Rodent-Like Mammals Thrived in the Ancient Arctic Before Dinosaur Extinction

Posted on May 20, 2026 by Igor Mitreski

Paleontologists have identified three new species of multituberculate mammals: Camurodon, Kayaku Gluk Peregrinus, and Crab Cosmodon Polaris. These fascinating creatures thrived in the polar forests around 73 million years ago. Notably, Kayaku Gluk Peregrinus shows a strong connection to Mongolian species, providing the earliest direct evidence of polytuberculates migrating from Asia to North America. This discovery challenges the long-held belief that the Arctic was evolutionarily isolated.

Reconstruction of the Late Cretaceous paleoenvironment of Alaska. Image credit: James Havens.

These species ranged in size between a mouse and a rat. Multituberculates are notable for being the longest-surviving group of mammals in Earth’s history, existing for over 100 million years from the Jurassic period until the end of the Eocene epoch, about 35 million years ago.

Remarkably, they survived the Chicxulub impact that led to the extinction of non-avian dinosaurs 66 million years ago.

Scientists have been intrigued by the longevity of multituberculates, and the discovery of these three new Arctic species may hold vital clues.

Dr. Sarah Shelley, a paleontologist at the University of Lincoln, stated, “Although polar regions lack the biodiversity of tropical areas, they have been vibrant habitats where life has thrived for eons.”

Fossil teeth from Camurodon, Kayaku Gluk Peregrinus, and Crab Cosmodon Polaris were found in a deposit dating back 73 million years in the Prince Creek Formation, located in the Arctic Circle.

These ancient creatures thrived even in a harsh environment marked by long winters, freezing temperatures, and potential food shortages.

“These three new mammal species bolster evidence that this ancient Arctic region was a habitat for unique polar-adapted species,” noted Dr. Patrick Druckenmiller, a paleontologist at the University of Alaska Fairbanks.

The research revealed significant variations in tooth shape among the three species, implying that they likely had diverse diets.

Camurodon exhibited herbivorous teeth, while Kayaku Gluk Peregrinus displayed characteristics of an omnivore, likely consuming both insects and plants.

Crab Cosmodon Polaris also seems to have been omnivorous, with a possible diet primarily consisting of plants.

In environments with limited food sources, the ability to adapt and diversify diets may have been key to the coexistence of various multituberculate species.

“Such adaptability may have also enabled them to survive the asteroid impact,” Dr. Shelley observed.

Researchers found that Kayaku Gluk Peregrinus is closely related to species native to modern-day Mongolia, indicating that these ancestors migrated from Asia to North America.

This migration is estimated to have occurred around 92 million years ago, marking one of the earliest known instances of mammals crossing continents.

“This finding implies that there was a land route between Asia and North America that facilitated movement for these small mammals,” said Professor Jerin Eberle, curator at the University of Colorado Museum of Natural History.

“This land bridge was already active around 90 million years ago.”

This discovery adds to the understanding of how species have migrated across continents, reshaping ecosystems throughout history.

“This challenges our perspective on native species,” Dr. Shelley remarked.

“Deep moments like these remind us that a place isn’t merely a dot on a map, but a tapestry of overlapping histories related to its landscape and inhabitants.”

The findings are detailed in a recent study published in the Proceedings of the National Academy of Sciences.

_____

Sarah L. Sherry et al. 2026. Arctic ecosystems influenced the dispersal and diversification of mammals prior to the Cretaceous-Paleogene mass extinction. PNAS 123 (22): e2601794123; doi: 10.1073/pnas.2601794123

Source: www.sci.news

Newly Discovered Giant Dinosaur Species in Thailand Unveils Asia’s Hidden Diversity of Ancient Giants

Posted on May 15, 2026 by Igor Mitreski

Paleontologists have unveiled an exciting discovery: a new genus and species of Somphospondylan titanosaur dinosaur, heralded as the largest ever found in Southeast Asia. Fossilized bones uncovered in Thailand provide compelling evidence that this region once hosted a remarkably diverse array of giant herbivores during the Early Cretaceous period.

Reconstruction of the life of Nagatitan chaiyapumensis in the arid floodplains of the Late Early Cretaceous Aptian-Albian period. Image credit: Pachanop Boonsai.

This newly described dinosaur species inhabited what is now northeastern Thailand approximately 113 million years ago.

Named Nagatitan chaiyapumensis, this ancient giant measured about 27 meters (89 feet) in length and weighed between 25 and 28 tons.

During its time, it coexisted with smaller plant-eating dinosaurs like iguanodonts and early ceratopsians, as well as predatory dinosaurs such as carcharodontosaurs and spinosaurs, alongside sharks, turtles, crocodile relatives, and pterosaurs.

“Our dinosaur is large by most standards, likely weighing at least 10 tons more than Dippy” (referring to Diplodocus carnegie), stated lead author Titiut (Pers) Sesapanitisakul from University College London.

“However, it still pales in comparison to massive sauropods like Patagotitan (60 tons) and Luyangosaurus (50 tons).

The fossil of Nagatitan chaiyapumensis was excavated from the Khok Kruat Formation in Chaiyaphum Province, Thailand.

“We consider Nagatitan chaiyapumensis the ‘last giant’ of Thailand,” Sesapanitisakul explained, “because it was found in a rock formation that contains the youngest dinosaurs.”

“Younger sediment deposited towards the end of the dinosaur era is unlikely to reveal dinosaur remains, as the area transformed into a shallow ocean by then.”

“This could represent the final or most recent large sauropod discovered in Southeast Asia.”

To classify Nagatitan chaiyapumensis, paleontologists compared its anatomy with over 150 other dinosaur species, situating it within the sauropod family tree.

The analysis established that the new species belongs to Euhelopodidae, a group of Somphospondylan titanosaurs primarily found in Asia.

This group also includes notable species such as Puwiangosaurus cylindornae from Thailand and Tanvayosaurus hofeti from Laos.

“This discovery highlights a trend of increased body size among Asian titanosaurs during the Mid-Cretaceous, likely driven by rising temperatures and the expansion of suitable habitats,” the researchers commented.

The identification of Nagatitan chaiyapumensis enhances the known diversity of sauropods in Southeast Asia and significantly contributes to our understanding of titanosaurs’ biogeography in this region.

The team’s paper has been published in the scientific journal Scientific Reports.

_____

T. Setapanitisakul et al. 2026. The first sauropod dinosaur discovered from the Early Cretaceous Khok Kruat Formation in Thailand enriches the diversity of vertebrate titanosaurids in Southeast Asia. Scientific Reports 16, 12467; doi: 10.1038/s41598-026-47482-x

Source: www.sci.news

Discover a New Species of Giant Long-Necked Dinosaur in Argentina

Posted on May 12, 2026 by Igor Mitreski

Fossils discovered at a secluded ranch in Argentina reveal a new genus and species of large sauropod dinosaur, identified by an international team of paleontologists from Ludwig-Maximilians-University Munich.

Reconstruction of Vicaracosaurus dionydei. Image credit: Felipe Cutro-Lev.

The newly identified sauropod species roamed the southern region of the Gondwana supercontinent during the Late Jurassic period, approximately 157 million years ago.

Named Vicaracosaurus dionydei, this dinosaur measured around 20 meters (65 feet) in length.

“Sauropods are a key lineage of dinosaurs, representing one of the most significant groups of herbivorous vertebrates from the Mesozoic era,” said lead author Alexandra Reuter, a doctoral student at Ludwig-Maximilians-University Munich, alongside her research team.

“These giant herbivores first emerged in the late Triassic period and thrived until the end of the Cretaceous period.”

“Sauropods displayed considerable taxonomic diversity and included the largest terrestrial animals in history.”

“Neosauropoda eventually branched into two primary clades, Diplodocoideae and Macronariidae, early in their evolutionary journey. This major classification has been widely accepted since the 1990s, though there is ongoing debate regarding the classification of many Jurassic taxa into these subclades or Neosauropoda as a whole.”

Fossil remains identified as Vicaracosaurus dionydei, including vertebrae, ribs, and parts of a hip joint, were first reported to paleontologists in March 2001 by local farmer Dionid Mesa.

This fossil site belongs to the Canadon Carcareo Formation, located in central to northern Chubut province, Argentina.

Historically, researchers have relied heavily on fossils from North America, Europe, and other Northern Hemisphere regions to piece together the evolution of neosauropods.

Both the Canadon Carcareo Formation and the Tendaguru Formation in Tanzania stand out as rare Gondwanan deposits preserving skeletons of multiple sauropods.

“For years, the only significant archaeological site in the southern continent was in Tanzania,” stated lead author Professor Oliver Rauchat, a paleontologist at the Bavarian Institute of Paleontology and Geology, as well as Ludwig-Maximilians-University of Munich.

“The fossils from the Chubut province, including Vicaracosaurus dionydei, provide critical comparative material that enhances our understanding of these creatures’ evolutionary history, particularly in the Southern Hemisphere.”

Fossil evidence indicates that Vicaracosaurus dionydei is part of a giant herbivore group known as Macronaria, which later gave rise to iconic giants like Brachiosaurus.

Yet, this new dinosaur’s anatomy also shows remarkable similarities to diplodocids, another sauropod lineage that includes famous species like Diplodocus.

To ascertain its position within the dinosaur family tree, researchers employed two distinct phylogenetic datasets for analysis.

Most analyses positioned Vicaracosaurus dionydei as sharing traits with Macronaria and Brachiosauridae, including Brachiosaurus and the African giant Giraffatitan.

“Our phylogenetic analysis indicates that Vicaracosaurus dionydei is closely related to brachiosaurids, making it the earliest known brachiosaur to inhabit South America during the Jurassic period,” Reuter concluded.

The research team’s paper was published in the online journal Peer J.

_____

A. Reuter et al. 2026. Vicaracosaurus dionydei, a new giant herbivorous dinosaur (sauropod) from the Late Jurassic Canadon-Carcareo Formation in Argentina and insights into the early evolution of giant sauropods. Peer J 14: e20945; doi: 10.7717/peerj.20945

Source: www.sci.news

Ancient Sauropod Dinosaur Fossil Discovered in China: Insights into Prehistoric Giants

Posted on May 5, 2026 by Igor Mitreski

A newly discovered genus and species of Masopodan sauropodomorph, named Kounryu Hōmei, has been identified from a partial skeleton found in southwestern China, dating back to the early Jurassic period. This remarkable dinosaur represents a crucial link between early herbivores and the massive four-legged sauropods that would later dominate the Mesozoic Era.

Artist’s impression of Kounryu Hōmei. Image credit: Connor Ashbridge / CC BY 4.0.

Kounryu Hōmei inhabited what is now China approximately 190 million years ago during the early Jurassic period.

Fossil evidence suggests that this dinosaur measured about 9 to 10 meters (30 to 33 feet) in length, making it one of the largest known early-branching sauropods unearthed in China.

This species belongs to the Masopodan group, which existed from the Late Triassic to the Late Cretaceous.

“The Early Jurassic was a key era in dinosaur evolution, marking the diversification and emergence of sauropod dominance in terrestrial ecosystems,” stated Dr. Ya-Ming Wang from the China Museum of Geology and colleagues.

“Within this group, non-sauropod Masopoda sauropods played a significant role in the evolutionary trajectory leading to the distinctive large body shapes associated with sauropods.”

“Therefore, understanding the anatomy, diversity, and paleobiogeography of these early-diverging sauropods is essential for unraveling the origins of one of the most successful dinosaur clades, the sauropods.”

The partial skeleton of Kounryu Hōmei was discovered in the Fengjiahe Formation located in Luming Town, Yunnan Province, China.

The specimen consists of the neck, back, tail vertebrae, and part of the hip joint.

Analysis of these fossils revealed an unusual combination of traits, indicating an alternative evolutionary path. Notably, it had a strong, elongated tail rather than the long neck typically associated with large dinosaurs.

Despite its relatively short neck for its body size, the tail may have played a balancing role, enabling this dinosaur to stand on its hind legs and feed.

Through phylogenetic analysis, researchers found that Kounryu Hōmei occupies a pivotal evolutionary position between early sauropods and more advanced forms closer to true sauropods.

“The discovery of this new specimen greatly enriches the known Early Jurassic dinosaur fauna of southwestern China,” the authors remarked.

“This provides essential new anatomical features that enhance our understanding of morphological differences and evolutionary patterns among early-diverging sauropods.”

The findings were published in the Royal Society Open Science on March 25th.

_____

Hu Shaobin et al. 2026. A neosauropod dinosaur discovered from the Lower Jurassic Fengjiahe Formation in Dali, Yunnan Province, China. R Soc Open Science 13 (3): 252219; doi: 10.1098/rsos.252219

Source: www.sci.news

Scientists Uncover Terrifying ‘Kraken’: The True Apex Predator of the Dinosaur Era

Posted on April 24, 2026 by Igor Mitreski

Scientists have recently uncovered that giant octopuses, reaching lengths of up to 19 meters (62 feet), were the true apex predators of the ocean during the dinosaur era.

In a groundbreaking study published in the magazine Science, researchers examined the fossilized jaws of two octopus species: Nanaimoteutis Zeretsky and N. Hagarty. These fossils were recovered from Late Cretaceous deposits dating back 100 million to 72 million years ago.

The extensive wear observed on the jaws of these adult specimens indicates that these colossal creatures were powerful, active carnivores, capable of crushing hard shells and bones. The largest octopuses of this time rivaled the size of the ocean’s largest marine reptiles.

According to Yasuhiro Iba, an associate professor at Hokkaido University, “They lived in the oceans during the age of the dinosaurs, alongside marine reptiles, large fish, sharks, ammonites, and large-shelled animals” as reported by BBC Science Focus.

Nanaimoteutis likely utilized its impressive size and extended arms for capturing prey while employing its powerful jaws to crush shells and bones, making it a formidable, intelligent predator at the top of the ocean food web.

In their research, scientists discovered 12 previously hidden octopus jaws through an innovative technique called digital fossil mining. This method transforms the interiors of rocks into high-resolution image datasets, allowing AI to create 3D models of fossils.

Unlike sharks and reptiles, this giant was at the top of the food chain despite its soft body – Photo courtesy of Hokkaido University

According to Iba, this advanced method can enhance fossil discovery rates by over 10,000 times compared to traditional techniques.

The asymmetrical wear on these jaws suggests a potential unilateral preference, indicating that these ancient octopuses may have exhibited behaviors similar to modern species, such as arm and eye preference, implying a remarkable level of intelligence.

These remarkable creatures might be the largest invertebrates ever recorded, earning Iba’s team the nickname “Cretaceous Kraken.”

However, the descendants of these octopuses now inhabit the depths of the ocean, having been displaced by newer generations of apex predators.

As Iba noted, “It was probably overtaken by a modern predator, such as a whale.”

Read more:

Source: www.sciencefocus.com

Newly Discovered Triassic Dinosaur Species Unearthed in New Mexico

Posted on April 18, 2026 by Igor Mitreski

A newly identified genus and species of carnivorous herrerasaurid dinosaur has been revealed from a well-preserved skull unearthed in northern New Mexico.

Artistic rendition of Ptychoterates buculentus. Image credit: Megan Sodano / Virginia Tech.

This newly discovered dinosaur species lived approximately 201 million years ago during the Rhaetian period of the Late Triassic era.

Identified as Ptychoterates buculentus, this species offers a rare glimpse into a lesser-known chapter of dinosaur evolution.

“Dinosaurs emerged during the Carnian period (237 to 227 million years ago) in the early Late Triassic and eventually branched into three lineages that thrived into the Jurassic: ornithischians, theropods, and sauropods,” explained Virginia Tech paleontologists Simba Srivastava and Stirling Nesbitt.

“While most of the earliest dinosaur fossils have been found in high-latitude regions of Pangea (present-day Brazil, Argentina, Zimbabwe, and India), comparable dinosaur remains from lower latitudes (like Late Triassic deposits in the southwestern United States and Morocco) are rare.”

The fossil remains of Ptychoterates buculentus include a nearly complete skull, which features an intact braincase and the majority of the skull roof, discovered in 1982 at the Coelophysis Quarry in northern New Mexico.

The skull measures about 22 cm (9 inches) in length, indicating it was a relatively tall and narrow-headed dinosaur.

“The skull reveals this species had prominent cheekbones, a broad braincase, and likely a short, deep snout,” added the paleontologist.

“These characteristics are the first of their kind seen in early dinosaurs, highlighting the ongoing evolution of these magnificent creatures.”

Ptychoterates buculentus belongs to one of the earliest-known families of carnivorous dinosaurs, the Herrerasauria.

This species is closely related to two other Triassic dinosaurs, Tawa Harae and Chindesaurus briansmalli.

These species form part of a newly defined clade, Morphoraptora, characterized by a mix of anatomical traits found in both primitive dinosaurs and later theropods.

“Our anatomical comparisons with other Triassic archosaurs support the identification of Ptychoterates buculentus as a new taxon within the saurischian dinosaurs, closely linked to Tawa Harae,” explained the researchers.

“More broadly, our findings position Ptychoterates buculentus as a member of Morphoraptora, a clade known primarily from Late Triassic deposits in the southwestern United States.”

Previously, scientists believed that by the late Triassic period, the earliest lineages of carnivorous dinosaurs had vanished, replaced by more advanced theropods.

However, the discovery of Ptychoterates buculentus indicates that some of these lineages survived much longer than anticipated, at least in the lower latitudes of the ancient supercontinent Pangea.

“Ptychoterates buculentus was found in strata that appear to date just before the Great Extinction at the end of the Triassic, and members of this family never appeared again, suggesting that this group perished due to the mass extinction,” the scientists noted.

“This finding necessitates a reevaluation of the end-Triassic extinction’s impact, showing that it not only eliminated competing dinosaur species but also long-established dinosaur lineages,” Srivastava added.

“Furthermore, since herrerasaurids have not been discovered elsewhere in the Late Triassic, it is likely that what is now the American Southwest served as the final refuge for these dinosaurs.”

The discovery of Ptychoterates buculentus is detailed in a research paper published in this week’s edition of the journal Paleontology Papers.

_____

Simba Srivastava & Sterling J. Nesbitt. 2026. A new taxon of saurischian dinosaurs (Triassic: modern Norian or Rhaetian) from Coelophysis Quarry in New Mexico, USA, highlighting the diversity of Herrerasaurus in the Late Triassic. Paleontology Papers 12 (2): e70069; doi: 10.1002/spp2.70069

Source: www.sci.news

Fossil Evidence Reveals Tyrannosaurus Attack on Duck-Billed Dinosaur

Posted on March 23, 2026 by Igor Mitreski

Discover the Semi-completed Skull of an Adult Edmontosaurus – A captivating snapshot from the Late Cretaceous period, preserved at the Montana State Museum of the Rockies, showcases a dramatic encounter where a Tyrannosaurus rex attacks a duck-billed dinosaur.

A striking scene of a Tyrannosaurus rex attacking an adult Edmontosaurus. Image credit: Jen Hall.

This damaged Edmontosaurus skull was unearthed in 2005 within the Hell Creek Formation of eastern Montana.

Now housed in the Museum of the Rockies’ paleontology collection, this fossil offers a remarkable detail: the interior of the skull is filled with Tyrannosaurus teeth.

According to Taia Winberg-Henzler, a doctoral student from the University of Alberta, “While bite marks on fossils are somewhat common, discovering embedded teeth is exceptionally rare.”

“Analyzing these teeth, especially those lodged in a skull, allows us to identify the bitten and the biter,” she explains.

“This phenomenon enables us to envision the harrowing encounter involving this Edmontosaurus. It’s akin to being a detective at a prehistoric crime scene.”

Comparative analysis of the embedded teeth with all carnivorous species from the Hell Creek Formation revealed a match with the Tyrannosaurus. A CT scan of the skull provided deeper insights into this event.

“Fossils like this one are particularly fascinating because they capture the behavior of a Tyrannosaurus rex attacking this herbivore,” states John Scannella, the curator of paleontology at the Museum of the Rockies.

“With no signs of healing around the embedded Tyrannosaurus teeth, it suggests that the Edmontosaurus may have been deceased at the time of the attack or succumbed to its injuries.”

Based on the way the teeth are embedded in the nose of the Edmontosaurus, “This indicates what often transpires when predators kill their prey,” Winberg-Henzler notes.

“The force required to embed these teeth into the bone also signifies the use of lethal strength.”

“To me, this paints a chilling picture of the final moments for this Edmontosaurus,” she adds.

“The typical feeding habits of the Tyrannosaurus—considered one of the largest carnivores to ever roam the Earth—have sparked extensive research and debate over the years,” Dr. Scannella remarks.

“Insights gained from the teeth embedded within the Edmontosaurus skull allow for a deeper understanding of Tyrannosaurus behavior.”

For detailed findings, refer to the published study in the online journal PeerJ.

_____

TCA Winberg-Henzler and JB Scannella. 2026. Behavioral Effects of Tyrannosaurus Teeth and Associated Tooth Marks Embedded in an Articulated Skull of Edmontosaurus from the Hell Creek Formation in Montana. PeerJ 14: e20796; doi: 10.7717/peerj.20796

Source: www.sci.news

New Herbivorous Dinosaur Species Discovered in South Korea: A Breakthrough in Paleontology

Posted on March 19, 2026 by Igor Mitreski

A newly discovered species of small herbivorous dinosaur has been unveiled from a partial skeleton of a juvenile found in South Korea.

Artist’s interpretation of Durisaurus humini. Image courtesy of Jun Song Yi.

Durisaurus humini, a dinosaur species that thrived in what is now Korea during the mid-Cretaceous period, approximately 113 to 94 million years ago.

This prehistoric species belongs to the Thescelosauridae family, a group of bipedal dinosaurs known to populate East Asia and North America during the Cretaceous.

“The fossil record of dinosaur skeletons in South Korea has historically been limited in abundance and completeness,” stated paleontologist Dr. Jeong-yoon Jeong from the University of Texas at Austin and Chonnam National University.

“Currently, only two dinosaur species from South Korea have been recognized, both characterized by partial posterior skulls from the late Cretaceous period: Coriaceratops fasongensis and the newly identified Collenosaurus bosongensis from the Senso Zaibatsu.”

The fossilized remains of Durisaurus humini were uncovered in 2023 within mid-Cretaceous rocks, specifically in the Nishiroyama layer on the southwestern coast of the Korean Peninsula.

The specimen encompasses a skull, vertebrae, hind limbs, and multiple bezoars (digestive stones).

Advanced X-ray micro-computed tomography (micro-CT) allowed researchers to reveal hidden anatomical details of the dinosaur’s interior embedded within the rock.

With a fuzzy coat, the dinosaur was likely about the size of a turkey but still a juvenile. Durisaurus humini may have eventually reached double this size.

Histological analysis suggests that this individual was very young, possibly around 2 years old.

“It would have been incredibly cute, resembling a young lamb,” commented Julia Clark, a paleontologist at the University of Texas at Austin.

Durisaurus humini marks the first new dinosaur species discovered in South Korea in 15 years, and it is the first dinosaur fossil with a partial skull to be found in the country.

“Upon discovering the specimen, we immediately noted some preserved leg bones and vertebrae,” Dr. Jung said.

“We were pleasantly surprised to find parts of the skull and other bones hidden within the rock blocks, creating significant excitement among the team.”

The clusters of gastroliths and their dimensions suggest that Durisaurus humini may have had a more omnivorous diet than previously assumed.

“The morphology of the gastroliths associated with Durisaurus humini and other early neoplacolates may imply a generalized or omnivorous dietary approach for this group,” the researchers noted.

“However, variations in gastric anatomy and bezoar use observed in modern birds indicate a cautious approach is necessary when interpreting dietary habits of non-avian dinosaurs.”

This groundbreaking discovery emphasizes the potential for further skeletal finds in South Korea, particularly at paleontological sites like Afed, where environmental conditions differ from those at locations known for rich trace fossil deposits.

Durisaurus humini suggests a greater diversity of Cretaceous dinosaurs in Korea than currently reflected in the trace fossil record,” the authors concluded.

For detailed insights, refer to their paper, published today in the online journal Fossil Record.

_____

J. Jung et al. 2026. A new species of dinosaur discovered in Korea and its implications on the diversity of early-diverging neoplates. Fossil Record 29 (1): 87-113; doi: 10.3897/fr.29.178152

Source: www.sci.news

Newly Discovered Dinosaur Could Change Our Understanding of Tyrannosaurus Origins

Posted on March 12, 2026 by Igor Mitreski

A 74-million-year-old leg bone unearthed from a fossil bed in New Mexico Tyrannosaurus rex suggests groundbreaking insights in a recent study published in Scientific Reports.

This discovery supports the theory that Tyrannosaurus did not migrate from Asia, but instead originated in what is now the American Southwest. This shift in understanding implies that the group evolved into giants much earlier than previously believed.

The shin bone, found in the Kirtland Formation of New Mexico and dating to the late Campanian period, measures 96 centimeters (3.1 feet) long—approximately 84 percent the size of the largest known Tyrannosaurus specimen’s tibia.

Based on its measurements, researchers estimate that the animal weighed around 4,700 kg (10,400 lb), making it the largest known Tyrannosaurus of its time—roughly 50 percent heavier than its contemporary rivals.

The researchers propose three possible origins for the bone: it may belong to a particularly large theropod dinosaur, identified as Vista hebersol; it could represent a newly recognized lineage of giant tyrannosaurs; or it might be an early member of the Tyrannosaurini, related to Tyrannosaurus and its closest relatives.

Of these theories, the authors believe the last is the most plausible. Lead researcher Dr. Nicholas Longrich from the University of Bath noted that the bones closely resemble those of Tyrannosaurus.

“This sounds like Tyrannosaurus,” he remarked in an interview with BBC Science Focus. “If these bones were found in the same beds we know Tyrannosaurus were found, no one would doubt it.”

This bone belonged to an animal that predates Tyrannosaurus by 8 to 9 million years – Photo credit: Nick Longrich

This suggests that the Tyrannosaurus lineage may have originated in southern North America, with connections to the giant tyrannosaurus, Tyrannosaurus macraiensis, identified from the slightly younger Hall Lake Formation in New Mexico. Longrich discovered this latest bone while photographing specimens on a museum shelf.

Large-scale clustering of Tyrannosaurus remains in the American Southwest indicates that this lineage likely evolved in that area before dispersing across the continent, millions of years prior to their emergence further north.

Further excavations of the Kirtland Formation may help clarify the ownership of this bone. Longrich expressed that “the potential for new materials to be discovered is very high,” noting that teeth might be a promising avenue for discovery due to their superior preservation compared to bones.

A more complete skeleton would allow researchers to formally name the species and determine if it represents a direct ancestor of Tyrannosaurus or an early relative.

Read more:

Source: www.sciencefocus.com

Scientists Uncover 90 Million-Year-Old Dinosaur ‘Rosetta Stone’ in Major Paleontological Discovery

Posted on March 6, 2026 by Igor Mitreski

A groundbreaking discovery of a 90-million-year-old fossil in Argentina is reshaping our understanding of the evolutionary history of a unique group of bird-like dinosaurs. This find helps settle a longstanding debate regarding their distribution across the ancient world.

The fossils detailed in Nature belong to Arunachetri seropolisiensis, a member of the Alvarezaurus family. This small dinosaur is characterized by its tiny teeth and stout arms, which end in a prominent single thumb claw.

While most well-preserved Alvarezsaurus fossils have been discovered in Asia, the existence of Alvarezsaurus in South America raises intriguing questions due to the vast ocean separating these continents.

A nearly complete skeleton uncovered at the La Buitrera fossil site in northern Patagonia has provided remarkable evidence regarding this species. This region was also home to primitive snakes and small saber-toothed mammals.

“Creating a nearly complete, articulated animal from a fragmented skeleton is akin to discovering the Rosetta Stone of paleontology,” stated Peter Makowiecki, a professor at the University of Minnesota, and the study’s first author.

Unlike their later relatives, Arunashetri had longer arms and larger teeth. This indicates that Alvarezsaurids likely reduced their body size before evolving the characteristic small limbs and teeth suited for an ant and termite diet.

“Our study suggests that alvarezsaurids form a compact group of dinosaurs, with species sizes ranging from crows to humans,” Makowiecki told BBC Science Focus. “Body size appears to fluctuate within this limited range without a clear trend.”

Peter Makowiecki discovers fossilized bones in Patagonia’s La Buitrera Fossil Field – Photo credit: Minyoung Son, University of Minnesota

This discovery also addresses an intercontinental mystery. A detailed anatomical study of Arunashetri led Makowiecki and his team to examine fossil collections globally. “We found other Alvarezaurids hiding in plain sight,” he noted.

“These species, which existed during the Jurassic period in North America and the Early Cretaceous in Europe, enhance our understanding of Alvarezsaurus’s widespread presence prior to the major rift between the Northern and Southern Hemispheres.”

Approximately 200 million years ago, all of Earth’s continents formed a single supercontinent named Pangea. This landmass gradually fragmented over tens of millions of years, evolving into its current configuration while transporting its fauna along with it.

The research team is preparing additional specimens from the same site, though Professor Makowiecki has remained tight-lipped about their specifics. “The new specimen confirms some of our findings regarding size and specialization,” he disclosed. “Currently, we have no further plans.”

Read more:

This version maintains SEO optimization by incorporating keywords, improving readability, and retaining necessary HTML tags.

Source: www.sciencefocus.com

Unearthed in Canada: Rare Fossil of Baby Dome-Headed Dinosaur Discovered

Posted on March 3, 2026 by Igor Mitreski

For years, the fossil record of pachycephalosaurs (dome-headed dinosaurs) has primarily consisted of fossilized skulls. In contrast, the postcranial remains of young pachycephalosaurs have remained largely unexplored. Recent paleontological findings have unveiled the youngest known example of a pachycephalosaur body, shedding light on how these fascinating dinosaurs grew and moved during their early months of life.

Reconstruction of the life of the pachycephalosaur individual CMNFV 22039 in a typical environment of the Upper Maastrichtian French Formation. Image credit: Caitlin Lindblad.

Paleontologist Brian Moore from Carleton University and his team noted that pachycephalosaurs predominantly comprised small, bipedal dinosaurs (ranging from 2 to 6 meters long) found in Asia and North America during the Santonian to Maastrichtian periods (85 to 66 million years ago).

This clade is particularly recognized for its unique frontal and parietal bones, which merge to create a bulbous dome on their skulls.

The cranial elements surrounding this dome are occasionally integrated into the structure, often featuring nodes, spikes, and other decorative traits.

Notably, the frontoparietal dome is the most resilient part of the pachycephalosaur skeleton (besides the teeth), resulting in a fossil record that heavily favors partial skull remains.

Consequently, much of the understanding regarding the ontogeny and phylogeny of pachycephalosaurs relies significantly on skull morphology.

The recently described pachycephalosaur specimen, cataloged as CMNFV 22039, dates back to roughly 67 million years ago during the Maastrichtian period of the Late Cretaceous.

This fossil was discovered in the French Formation, the youngest of the five Maastrichtian formations located in southern Saskatchewan, Canada.

Remarkably, this dinosaur was likely under a year old at the time of its death, marking it as the youngest known pachycephalosaur from fossil records.

“Despite its small size (estimated at just 90 centimeters or 3 feet), the skeleton displays several features characteristic of pachycephalosaurs,” the paleontologists confirmed.

These findings indicate that many traits used to identify adult pachycephalosaurs were present from a very young age.

Additionally, they provide insight into how juvenile pachycephalosaurs moved. In comparison to adults, the hindlimbs of juveniles were proportionately longer, suggesting that they had a more agile physique during their early development.

As the dinosaur matured, its body seemingly transitioned to the more robust proportions observed in adults, indicating a shift in physical capabilities as it increased in size and weight.

“The relatively long hind limbs of juveniles compared to those of adults imply a likely negative ontogenetic allometry in the hind limbs,” the researchers concluded.

The team’s findings are detailed in a paper published in the February 26th issue of the Journal of Vertebrate Paleontology.

_____

Brian R.S. Moore et al. Posterior skull of ontogenetically youngest known pachycephalosaur (Dinosauria: Ornithischia). Journal of Vertebrate Paleontology, published online on February 26, 2026. doi: 10.1080/02724634.2026.2616325

Source: www.sci.news

90-Million-Year-Old Patagonian Fossils Uncover Key Insights into Alvarezauroid Dinosaur Evolution

Posted on February 26, 2026 by Igor Mitreski

Discover the fascinating skeleton of the Alvarezauroid dinosaur species Arunachetri seropolisiensis. This groundbreaking find includes two specimens from Patagonia, Argentina, along with two from the Northern Hemisphere, providing insights into how this enigmatic lineage of theropod dinosaurs evolved and dispersed before the separation of continents, challenging established beliefs regarding its origins.

Arunachetri seropolisiensis. Image credit: Gabriel Díaz Yanten, Universidad Nacional de Rio Negro.

Learn more about Arunachetri seropolisiensis, which thrived in Argentina during the Cenomanian period of the Late Cretaceous, approximately 90 million years ago.

This species was initially described from partial remains in 2012 and is categorized under Alvarez Sauroidea.

These unique small dinosaurs are noted for their tiny teeth and short arms, each ending in a prominent thumb claw.

“The Alvarezauroidea represents a mysterious clade of mainly small theropod dinosaurs, primarily found in the Jurassic to Cretaceous periods of Asia and South America,” states paleontologist Peter Makowiecki from the University of Minnesota, Twin Cities, along with his research team.

“Late Cretaceous Alvarezauroids are believed to have been carnivorous, primarily consuming ants, and possessing specialized forelimbs suitable for digging, microscopic supernumerary teeth, and heightened sensory abilities.”

“They are thought to have undergone evolutionary miniaturization alongside dietary specialization.”

The almost complete skeleton of Arunachetri seropolisiensis was discovered in the La Buitrera fossil site in Rio Negro, northern Patagonia.

Microscopic examination confirmed that this specimen was an adult, estimated to be at least four years old.

Weighing less than 0.9 kg (2 lb), it ranks as one of the smallest-known dinosaurs from South America.

In contrast to its later relatives, Arunachetri seropolisiensis featured longer arms and larger teeth.

Paleontologists conclude this indicates that some alvaresaurids transitioned into smaller forms well before they developed adaptations for an ant-based diet.

Researchers, by analyzing previously discovered alvaresaurid fossils housed in museums across North America and Europe, further demonstrate that these dinosaurs originated earlier than previously presumed, existing during the period when the continents were still part of the supercontinent Pangaea.

Their distribution appears to have resulted from the fragmentation of Earth’s landmass, making ocean crossings unlikely.

“Our biogeographical study suggests a Pangean ancestral distribution for Alvarezsauroroidea, indicating that the clade’s early history was primarily influenced by surrogates,” the scientists remarked.

Read their groundbreaking research in the paper published in Nature.

_____

PJ Makowiecki et al.. Discovery in Argentina reshapes the evolutionary narrative of a fascinating dinosaur clade. Nature published online on February 25, 2026. doi: 10.1038/s41586-026-10194-3

Source: www.sci.news

Discover the Tiny Predatory Dinosaur Lighter than a Chicken

Posted on February 25, 2026 by Igor Mitreski

Reconstruction of *Arunashetri seropolisiensis*

Credit: Gabriel Díaz Yantén, National University of Rio Negro.

Reconstruction of Arunashetri seropolisiensis — Reconstruction of *Arunashetri seropolisiensis*

Credit: Gabriel Díaz Yantén, National University of Rio Negro.

The nearly complete skeleton of a small dinosaur, weighing less than a domestic chicken, has provided significant insights into the evolution of Alvarezaurus, one of the smallest dinosaur species ever documented.

This 95 million-year-old fossil, identified as Arunashetri seropolisiensis, was unearthed in 2014 at the La Buitrera site in northern Patagonia, Argentina.

The first specimen of Arunashetri consisted of incomplete hind limb bones found in 2012. Peter Makowiecki from the University of Minnesota contributed to the research on this new fossil. At the time, only fragmentary remains were available, leaving the classification as a probable alvaresaurid. “We didn’t even know if it was a juvenile or an adult,” says Makowiecki.

“With the entire skeleton now complete, we suddenly have all the information required to understand how Arunashetri functioned. Its anatomical structure is both similar and distinct from other species, providing key insights into the evolution of Alvarezsaurus’s unusual anatomy,” notes Makowiecki.

The new fossil features very elongated and slender hind limbs, along with unexpectedly long forelimbs equipped with three well-developed fingers. Detailed analysis revealed that this dinosaur was an adult, estimated to be at least four years old.

It is believed that it weighed only 700 grams in its lifetime. “These specimens are incredibly small, even smaller than a chicken,” explains Makowiecki.

Previously, Alvarezsaurus was thought to be an early ancestor of birds. Recent findings clarify that while Arunashetri may have superficially resembled a bird, it, along with all Alvarezsaurus, are indeed non-avian theropods. “This new discovery confirms our understanding,” states Makowiecki.

It was once believed that all small alvaresaurids had short, robust forelimbs with prominent thumbs but reduced lateral digits and small teeth, interpreted as evolutionary adaptations for a diet of ants and termites. However, as Makowiecki points out, “Arunashetri does not fit that mold. Although it is a smaller member of the Alvarezauridae family, it signifies a relatively early branch in the evolutionary tree, hence its teeth and forelimbs remain quite substantial.”

In fact, he adds, its forelimbs are more characteristic of other theropods rather than anteater specialists. “Arunashetri, while smaller, structurally resembles a typical theropod. Considering its size, it likely consumed a significant variety of invertebrates, along with a broader prey spectrum,” he further explains.

This indicates that paleontologists still lack a full understanding of why these dinosaurs evolved to such small sizes. “We are left with a vague understanding that Alvarezsaurids successfully occupied a very small predator niche,” concludes Makowiecki.

Topics:

Source: www.newscientist.com

New Sauropod Dinosaur Species Discovered in Brazil: A Groundbreaking Find

Posted on February 24, 2026 by Igor Mitreski

Researchers in Brazil have unearthed a newly identified species of vertebrate sauropod dinosaur resembling those from Europe, hinting at an ancient migration route that once linked two continents, now divided by the Atlantic Ocean.

Artist’s impression of Dasosaurus tocantinensis. Image credit: TotalDino / CC BY 4.0.

This newly discovered dinosaur species lived approximately 120 million years ago during the Early Cretaceous period, a time when the world’s landmasses were consolidated within the southern supercontinent Gondwana.

Dubbed Dasosaurus tocantinensis, this dinosaur measured about 20 meters (66 feet) in length.

It belonged to the Somphospondyli clade, which includes titanosaur-like sauropods that thrived from the late Jurassic to the end of the Cretaceous period.

The partial skeleton of Dasosaurus tocantinensis was unearthed in the Itapecur Formation located in northeastern Brazil.

This dinosaur features distinct anatomical traits, such as elongated ridges and grooves on its caudal vertebrae, as well as a notably pronounced lateral bulge on its femur, characteristics not previously identified in any known species.

These unique features indicate that Dasosaurus tocantinensis lies outside the titanosaur lineage, a subgroup of sauropods that would later dominate the southern continents.

Interestingly, this new species appears most closely related to Galumbachitan morelensis, another sauropod that existed in present-day Spain around 122 million years ago.

The discovery not only catalogs a new species but also reinforces the idea that Early Cretaceous South America was not an isolated evolutionary niche.

Instead, it formed part of a vibrant network of land connections that facilitated dinosaur migrations between continents long before the Atlantic Ocean was fully formed.

“This finding expands the known diversity of Early Cretaceous sauropods in northern South America and underscores their biogeographical ties to Europe and other regions in northern Gondwana,” stated lead author Max Langer from the University of São Paulo and colleagues.

“Indeed, numerical biogeographical analyses suggest that a clade consisting of Dasosaurus tocantinensis and Galumbachitan morelensis originally arose in Europe, with their lineages migrating from Europe to South America through North Africa during the Valanginian (137 to 133 million years ago) and Aptian (121 to 113 million years ago) periods.”

The discovery of Dasosaurus tocantinensis was reported in a research paper published on February 12th in the Journal of Systematic Paleontology.

_____

Elver L. Mayer et al. (2026). A new European-like titanosaur from the Early Cretaceous of Brazil: Insights into the phylogeny, histology, and biogeography of Somphospondyli. Journal of Systematic Paleontology 24(1); doi: 10.1080/14772019.2025.2601579

Source: www.sci.news

Massive New Dinosaur Species Unearthed in Sahara Desert

Posted on February 23, 2026 by Igor Mitreski

Paleontologists have made an exciting discovery of a monumental new dinosaur species in a secluded area of the Sahara Desert. Named Spinosaurus mirabilis—which translates to “amazing spinosaurus” in Latin—this colossal creature roamed more than 95 million years ago in what is now Niger, far from the coastal regions typically associated with similar fish-hunting dinosaurs.

Measuring as long as a school bus and weighing several tons, Spinosaurus mirabilis stands out from other spinosaurs due to its distinctive scimitar-shaped crest on its head. This unique feature was so rare that researchers did not recognize its importance during the initial excavation in 2019; they only grasped its significance upon returning in 2022 to unearth additional specimens.

“This discovery was so sudden and surprising that it was incredibly exciting for our team,” said Paul Sereno, Professor of Organismal Biology and Anatomy at the University of Chicago. Sereno led the groundbreaking research, which was published in a 2016 Science study.

“I will cherish the moment we gathered around our laptops at camp to observe the new species for the first time, after one of our team members generated a 3D digital model of the bones we uncovered to assemble the skull. It was then that the full significance of the discovery became clear,” he added.

The interlocking upper and lower teeth of the skull form a lethal trap for slippery fish. Fish-eating is a proven adaptation found in ichthyosaurs, crocodiles, and pterosaurs, and distinguishes Spinosaurus from its dinosaur relatives. – Photo credit: Keith Ladzinski

Previous Spinosaurus fossils are mainly found near ancient coastlines. These dinosaurs, characterized by their long snouts and conical teeth reminiscent of modern crocodiles, were exceptionally adapted for hunting fish.

The extent of their aquatic capabilities is still debated, with some researchers asserting they were powerful swimmers, while others believe they spent most of their time paddling through shallow waters.

Interestingly, S. mirabilis was discovered hundreds of kilometers away from the nearest coast. Researchers propose that this region of Niger may have once been a lush forest landscape crisscrossed by rivers, rather than a coastal area.

Ana Lazaro, a participant in the 2022 Niger Expedition, holds the third and most complete head print known from the new spinosaurid *Spinosaurus mirabilis*. – Photo credit: Alvaro Simarro

“I envision this dinosaur had no difficulty entering 2 meters (6.5 feet) of water with its robust legs, but likely spent most of its time stalking through shallower areas, hunting for the day’s many large fish,” Sereno remarked.

Nevertheless, many mysteries remain about this new species and its closely related counterparts in the Spinosauridae family.

“This new discovery will only enhance its mystique,” said Steve Brusatte, a professor and paleontologist at the University of Edinburgh, who was not involved in the study. BBC Science Focus.

“This surprising discovery underscores that there is still much to learn about Spinosaurus. While dinosaurs have long been shrouded in enigma, each new fossil sheds light on their true nature, bringing Spinosaurus into clearer focus.”

Read more:

Source: www.sciencefocus.com

Unlocking Australia’s Ancient Past: Study Reveals 230 Million-Year-Old Dinosaur Footprints as the Oldest in the Country

Posted on February 3, 2026 by Igor Mitreski

Unearthed in 1958 by a young fossil hunter in Albion, Brisbane, Queensland, Australia, dinosaur footprints have been officially recognized as the continent’s oldest, dating back approximately 230 million years to the late Triassic period. This discovery indicates that dinosaurs inhabited the Brisbane region far earlier than previously thought by paleontologists.

Living fossils unearthed from Petrie Quarry, Albion, Brisbane, Queensland, Australia. Image credit: Anthony Romilio & Bruce Runnegar, doi: 10.1080/03115518.2025.2607630.

The 18.5 cm (7 in.) long dinosaur footprint was discovered at Petrie’s Quarry, part of the Aspley Formation, alongside a slab featuring narrow linear grooves interpreted as possible tail traces.

Both specimens were extracted before the quarry site was redeveloped, passing through several university collections since then.

“This is the only dinosaur fossil discovered in an Australian capital, highlighting how significant finds can remain hidden in plain sight,” stated Dr. Anthony Romilio, a palaeontologist from the University of Queensland.

“Urban development has rendered the original site inaccessible, leaving behind these footprints as the only evidence of dinosaurs in the area.”

The footprints show impressions of three forward-facing toes, with the central toe demonstrating a faint fan-shaped outline, characteristics typical of a bipedal dinosaur.

Advanced 3D modeling and morphometric analysis revealed that this footprint closely resembles the Ichnogenus Evazoum, commonly linked to early sauropod dinosaurs found elsewhere.

Based on the dimensions of the footprints, Dr. Romilio and Professor Bruce Rannegar estimated that the corresponding dinosaur stood about 78 centimeters (31 inches) tall at the waist and weighed around 144 kilograms (89 pounds).

Utilizing established scaling equations, researchers calculated the maximum potential running speed to be about 60 km/h (37 mph).

While no dinosaur skeletons have been found in the Aspley Formation, these footprints serve as the only direct evidence of dinosaur presence in this time and place.

“Dinosaurs may have walked along waterways, leaving their tracks preserved in sandstone that was later cut to build structures across Brisbane,” Dr. Romilio explained.

“If not for the foresight to conserve this material, the history of Brisbane’s dinosaurs would have remained completely unknown.”

“These footprints were made in sediment by large animals and exemplify a unique kind of trace fossil,” stated Professor Rannegar.

The associated tail print, approximately 13 centimeters (5 inches) long, aligns with structures interpreted as a dinosaur’s tail track. However, the authors caution that without preservation of the corresponding footprint in an appropriate location, its origin remains uncertain.

“The shallow linear grooves found in the tail block closely match reported tail drag traces, yet lack any remaining evidence of Manus or Pes. Their true identity remains ambiguous,” they noted.

“These grooves could have resulted from caudal contact in the orbits of prosauropods, but typically on-site and near the midline of such orbit, which isn’t applicable in this case.”

The team’s research paper has been published this week in The Alcheringa, Australian Journal of Paleontology.

_____

Anthony Romilio and Bruce Rannegar. Australia’s oldest dinosaur: Reproductive fossils unearthed from the Carnian Aspley Formation in Brisbane, Queensland, Australia. Alcheringa published online on February 1, 2026. doi: 10.1080/03115518.2025.2607630

Source: www.sci.news

Newly Discovered Small Herbivorous Dinosaur Species Found in Spain

Posted on February 2, 2026 by Igor Mitreski

A groundbreaking discovery has unveiled a new genus and species of small bipedal dinosaur from fossils found in Burgos, Spain.

Reconstruction of Foskeia pelendonum. Image credit: Martina Charnel.

Foskeia pelendonum thrived during the Early Cretaceous period, approximately 120 million years ago.

This newly identified species is part of the Rhabdodontomorpha, a group of ornithischian dinosaurs that existed primarily from the early to late Cretaceous period.

The diminutive dinosaur was roughly the size of a modern chicken, setting it apart from many of its larger ornithischian relatives.

“From the outset, we recognized the uniqueness of these bones due to their small size,” stated Dr. Fidel Torcida Fernández Baldor, a paleontologist at the Salas de los Infantes Dinosaur Museum.

“Remarkably, this study challenges established global theories regarding the evolution of ornithopod dinosaurs.”

“Miniaturization does not imply evolutionary simplicity. This skull is distinctive and highly specialized,” added Dr. Marcos Becerra from the National University of Córdoba.

“Foskeia pelendonum bridges a 70-million-year gap, serving as a small key to unlock a vast chapter of evolutionary history,” remarked Dr. Thierry Tortosa, a paleontologist at the Sainte-Victoire Nature Reserve.

“This is not a ‘mini’ iguanodon; it’s fundamentally different,” emphasized Dr. Tabata Zanesco Ferreira from the Federal University of Rio de Janeiro.

“Its anatomy is peculiar in a way that fundamentally alters the evolutionary tree,” said Dr. Penélope Cursado-Caballero from the University of La Laguna.

The fossilized remnants of at least five individuals of Foskeia pelendonum were excavated from the Vegaguete site in Burgos, Spain.

“This site is part of the Castrillo de la Reina Formation, located between Villanueva de Calazo and Salas de los Infantes,” the researchers noted.

Histological analysis confirmed that the largest specimen was a sexually mature adult.

“The microstructure of the bones suggests that at least one individual was an adult with a metabolic rate akin to that of small mammals and birds,” said Dr. Cohen Stein from Vrije Universiteit Bruxelles.

“Understanding growth and development is vital for comparing anatomical structures within Foskeia pelendonum and other species.”

“Juveniles often exhibit anatomical changes as they mature.”

Phylogenetic analysis indicates that Foskeia pelendonum is closely related to the Australian dinosaur Muttaburasaurus, extending the European clade Rhabdodontia.

“Our findings indicate that herbivorous dinosaurs comprise a natural group called Phytodinosauria,” stated Dr. Paul-Emile Dieudonné from the National University of Rio Negro.

“This hypothesis requires further examination with additional data.”

Despite its modest size, Foskeia pelendonum exhibits specialized dentition and postural changes during growth, adapting for rapid movement through dense vegetation.

“These fossils illustrate that significant evolutionary experiments occurred at both small and large body sizes,” Dieudonné concluded.

“The future of dinosaur research relies on recognizing the significance of small details.”

The discovery of Foskeia pelendonum is detailed in a research paper published in the journal Paleontology Papers.

_____

l-Emile Dieudonné et al. 2026. Foskeia pelendonum, a new rhabdodontomorph from the Early Cretaceous of Salas de los Infantes (Burgos Province, Spain), and a new lineage of ornithischian dinosaurs. Paleontology Papers 12 (1): e70057; doi: 10.1002/spp2.70057

Source: www.sci.news

New Troodontid Dinosaur with Thick Skull Discovered in Mexico

Posted on January 13, 2026 by Igor Mitreski

A groundbreaking study by a team of paleontologists from Mexico and the United States has unveiled a new species of bird-like dinosaur, Xenovenator Espinosai, notable for its exceptionally thick, dome-shaped skull. This unique adaptation suggests it may have engaged in headbutting behaviors during conflicts with its peers.

Reconstruction of the life of Xenovenator Espinosai. Image credit: Connor Ashbridge / CC BY 4.0.

This newly identified dinosaur species thrived during the late Cretaceous period, approximately 73 million years ago.

Xenovenator Espinosai is part of the Troodontidae family, which includes agile theropod dinosaurs closely related to modern birds.

The holotype and paratype specimens were uncovered during surface sampling in the Cerro del Pueblo Formation located in Coahuila state, northern Mexico, in the early 2000s.

While Troodontids are recognized for their larger brains and heightened sensory capabilities, this species distinguishes itself through an exceptionally thick skull roof.

The holotype specimen retains nearly the entire brain case, showcasing a strongly dome-shaped structure that reaches thicknesses of up to 1.2 cm.

CT scans reveal that the skull features a dense architecture with closely interlocked sutures and a rugged, textured exterior.

This structural resemblance to the reinforced skulls of dome-headed pachycephalosaurs highlights an evolutionary adaptation for intraspecific combat, particularly head-butting.

While display structures and combat weapons are common among many dinosaur species, detailed adaptations for fighting have yet to be recorded in non-avian maniraptoran theropods.

The paratype specimen of Xenovenator Espinosai shows less pronounced cranial thickening, which may indicate variability due to age or sex, suggesting that the most significant skull enhancements occurred later in development or were selective to one sex.

“The thickened, deformed skull of Xenovenator Espinosai is unparalleled among maniraptorans, with its precise function remaining unclear,” stated lead author Dr. Hector Rivera Silva from Museo del Desierto.

“Several traits that appear to serve no obvious survival advantage, such as cranial horns and crests, may be the result of sexual selection.”

“In contemporary mammals and birds, these attributes can be utilized for display or as weapons during courtship.”

“Considering our findings—skull thickening, cranial doming, and intricate sutures—it is likely that the domed skull of Xenovenator Espinosai was an adaptation for intraspecific combat,” they added.

This discovery marks the first documented case of a parabird exhibiting a specialized skull for combat among its species.

Interestingly, researchers noted that wrinkled frontal bones and similar features in the maxilla and nasal bones of troodontids may suggest widespread intraspecific fighting, with heightened intensity observed in Xenovenator Espinosai.

The phylogenetic analysis indicates that despite being part of a larger North American troodontid lineage, Xenovenator Espinosai’s distinctively thick, domed skull highlights its unique evolutionary niche within the group.

The recurrent evolution of intricate display features and weapons during the Cretaceous hints at the increasing importance of sexual selection in dinosaur evolution.

This finding enriches our understanding of the diversity among troodontid dinosaurs from southern Laramidia, offering rare insights into how even smaller, lighter theropods developed traits specialized for physical confrontation.

Researchers propose that related species like Xenovenator Robustus signify a distinct clade of heavily built troodontids endemic to the Southwest, emphasizing the uniqueness and diversity of southern Laramidian fauna.

“Sexual selection, encompassing adaptations for display and combat, was likely a pervasive phenomenon among dinosaurs during the Late Cretaceous period,” they concluded.

For further details on this discovery, refer to the research paper published in the journal Diversity.

_____

Hector E. Rivera-Silva et al. 2026. A troodontid theropod with a thick skull that lived in late Cretaceous Mexico. Diversity 18(1):38; doi: 10.3390/d18010038

Source: www.sci.news

Remarkable Discovery: 160 Million-Year-Old Dinosaur Footprints Unearthed in Chile

Posted on December 27, 2025 by Igor Mitreski

The recently uncovered theropod and sauropod footprints from the Late Jurassic Mahara Formation are the oldest dinosaur tracks documented in Chile and along the western edge of the ancient supercontinent Gondwana.

Palaeoartistic reconstruction of Quebrada Huatacon from the Late Jurassic period. Image credit: Nahuel Vazquez.

“The Late Jurassic fossil record highlights significant disparities in the density and distribution of dinosaur footprints between Laurasia and Gondwana,” stated Dr. Marco Yurac from the School of Paleontology and his colleagues.

“In Europe alone, numerous footprint sites have been identified, including regions in Italy, Croatia, Poland, Spain, Switzerland, France, Germany, and Portugal.”

“Moreover, North America boasts extensive track sites rich in ichthyological evidence.”

“Conversely, dinosaur footprints in Gondwana are relatively scarce and fragmentary, with notable exceptions like footprint-bearing outcrops in the High Atlas Mountains of Morocco.”

“Beyond these, ichthyological evidence is limited, with only a few records from Australia.”

“In South America, the majority of dinosaur footprints are found along the eastern coast, particularly in Brazil, Guyana, and Uruguay, with additional reports from northern locales like Colombia.”

“In contrast, on the western coast of South America, corresponding to Gondwana’s western boundary, Late Jurassic dinosaur footprints have only been discovered in Chile.”

A track consisting of four consecutive imprints from a large three-fingered dinosaur in the Mahalla Formation of Chile. Image credit: Yurac et al., doi: 10.1186/s13358-025-00419-9.

Paleontologists have discovered five distinct formations containing footprints within the Majara Formation in the Quebrada Huatacondo area of Chile.

These footprints were created by theropod and sauropod dinosaurs approximately 160 million years ago.

“Around 160 million years ago, northern Chile experienced cycles of flooding and drought,” explained the researchers.

“While the climate was primarily arid, temporary wetlands formed from seasonal water accumulation, attracting a variety of animals, from small theropods to massive carnivorous dinosaurs.”

“As dinosaurs traversed wet mud near these water sources, their footprints were imprinted into the soft sediment.”

“Subsequent flooding gently covered these tracks, preserving them for millions of years.”

The Majara footprints reveal the existence of giant (51-52.8 cm), large (43.5-46.5 cm), and medium-sized (25-27 cm) theropod dinosaurs.

One surface showcases over 25 footprints (ranging from 8 to 13 cm), attributed to microscopic theropods.

“These footprints represent the smallest theropod prints ever recorded in Chile, and likely extend across the entire western margin of Gondwana,” said the scientists.

Another surface is the only stratigraphic level exhibiting solely sauropod footprints (potentially undertracks).

“Due to their poor state of preservation, exact quantitative measurements were not feasible,” commented the authors.

“Nonetheless, analyses of the digital model suggest at least nine footprints with configurations indicative of potential movements.”

Paleontologists assert that this discovery represents the earliest known dinosaur footprints from Chile and the western margin of Gondwana.

“These footprints offer crucial insights for reconstructing the paleoenvironment and behavioral patterns of dinosaurs in northern Chile during the Late Jurassic, reflecting the temporary inhabitation of semi-arid floodplain and ephemeral wetland ecosystems,” the researchers concluded.

This significant finding is detailed in a research paper published in the Swiss Journal of Paleontology.

_____

M. Yurac et al. 2025. Upper Jurassic dinosaur footprints from the Mahara Formation of the Huatacondo region (Tarapaca Basin, Chile): Reassessment of known localities and discovery of new footprints. Swiss Journal of Paleontology 144, 72; doi: 10.1186/s13358-025-00419-9

Source: www.sci.news

Discover 6 Groundbreaking Dinosaur Species Unveiled in 2025

Posted on December 25, 2025 by Igor Mitreski

Zavasephale Rinpoche

Masaya Hattori

Meet the fascinating Zavasephale Rinpoche, a dome-headed dinosaur from Mongolia, dating back 108 million years. This remarkable creature is the oldest of its kind, with paleontologists describing its fossilized skull resembling a “cabochon gem.” While related species can grow up to 4 meters and weigh 400 kilograms, this juvenile measured around 1 meter in length and weighed approximately 6 kilograms.

<p xmlns:default="http://www.w3.org/2000/svg">
    <figure class="ArticleImage">
        <div class="Image__Wrapper">
            <img class="Image" alt="Spicomerus afar" width="1350" height="834" src="https://images.newscientist.com/wp-content/uploads/2025/12/05151921/SEI_276787454.jpg" srcset="https://images.newscientist.com/wp-content/uploads/2025/12/05151921/SEI_276787454.jpg?width=300 300w, https://images.newscientist.com/wp-content/uploads/2025/12/05151921/SEI_276787454.jpg?width=400 400w, https://images.newscientist.com/wp-content/uploads/2025/12/05151921/SEI_276787454.jpg?width=500 500w" sizes="(min-width: 1288px) 837px, (min-width: 1024px) calc(57.5vw + 55px)" loading="lazy" data-image-context="Article" data-image-id="2507371" data-caption="Spicomerus afar" data-credit="Matthew Dempsey"/>
        </div>
        <figcaption class="ArticleImageCaption">
            <div class="ArticleImageCaption__CaptionWrapper">
                <p class="ArticleImageCaption__Title">Spicomerus afar</p>
                <p class="ArticleImageCaption__Credit">Matthew Dempsey</p>
            </div>
        </figcaption>
    </figure>
</p>
<p>Scientists recently examined 165 million-year-old fossils from Morocco, leading to the identification of <em>Spicomerus afar</em>, a heavily armored dinosaur with a striking appearance. According to <a href="https://www.nhm.ac.uk/our-science/people/susannah-maidment.html">Suzanna Maidment</a> from the Natural History Museum, the unique features of this dinosaur led her team to describe it as "baroque."</p>

<p xmlns:default="http://www.w3.org/2000/svg">
    <figure class="ArticleImage">
        <div class="Image__Wrapper">
            <img class="Image" alt="Duonyx tsogtbatari" width="1350" height="964" src="https://images.newscientist.com/wp-content/uploads/2025/12/05151923/SEI_276787580.jpg" srcset="https://images.newscientist.com/wp-content/uploads/2025/12/05151923/SEI_276787580.jpg?width=300 300w, https://images.newscientist.com/wp-content/uploads/2025/12/05151923/SEI_276787580.jpg?width=400 400w" sizes="(min-width: 1288px) 837px, (min-width: 1024px) calc(57.5vw + 55px)" loading="lazy" data-image-context="Article" data-image-id="2507372" data-caption="Duonyx tsogtbatari" data-credit="Masato Hattori"/>
        </div>
        <figcaption class="ArticleImageCaption">
            <div class="ArticleImageCaption__CaptionWrapper">
                <p class="ArticleImageCaption__Title">Duonyx tsogtbatari</p>
                <p class="ArticleImageCaption__Credit">Masato Hattori</p>
            </div>
        </figcaption>
    </figure>
</p>
<p>The 90-million-year-old <em>Duonyx tsogtbatari</em>, found in the Gobi Desert, might remind you of Edward Scissorhands due to its bipedal stance and two elongated fingers. These fingers, each equipped with massive claws measuring up to 30 centimeters, were likely used to grasp branches for feeding.</p>

<p xmlns:default="http://www.w3.org/2000/svg">
    <figure class="ArticleImage">
        <div class="Image__Wrapper">
            <img class="Image" alt="Sri Rapax" width="1350" height="900" src="https://images.newscientist.com/wp-content/uploads/2025/12/05151928/SEI_276787719.jpg" srcset="https://images.newscientist.com/wp-content/uploads/2025/12/05151928/SEI_276787719.jpg?width=300 300w, https://images.newscientist.com/wp-content/uploads/2025/12/05151928/SEI_276787719.jpg?width=400 400w" sizes="(min-width: 1288px) 837px, (min-width: 1024px) calc(57.5vw + 55px)" loading="lazy" data-image-context="Article" data-image-id="2507373" data-caption="Sri Rapax" data-credit="Royal Belgian Institute of Natural Sciences, Brussels"/>
        </div>
        <figcaption class="ArticleImageCaption">
            <div class="ArticleImageCaption__CaptionWrapper">
                <p class="ArticleImageCaption__Title">Sri Rapax</p>
                <p class="ArticleImageCaption__Credit">Royal Belgian Institute of Natural Sciences, Brussels</p>
            </div>
        </figcaption>
    </figure>
</p>
<p>If you’re a fan of <em>Jurassic Park</em>, be wary of the <em>Sri Rapax</em>. This dinosaur, discovered in the Gobi Desert, features menacing claws and was likely one of the fiercest predators during its time, 75 to 71 million years ago, hunting in sprawling deserts and lakes.</p>

<p xmlns:default="http://www.w3.org/2000/svg">
    <figure class="ArticleImage">
        <div class="Image__Wrapper">
            <img class="Image" alt="Baminornis zhenghensis" width="1350" height="900" src="https://images.newscientist.com/wp-content/uploads/2025/12/05151936/SEI_276787651.jpg" srcset="https://images.newscientist.com/wp-content/uploads/2025/12/05151936/SEI_276787651.jpg?width=300 300w, https://images.newscientist.com/wp-content/uploads/2025/12/05151936/SEI_276787651.jpg?width=400 400w" sizes="(min-width: 1288px) 837px, (min-width: 1024px) calc(57.5vw + 55px)" loading="lazy" data-image-context="Article" data-image-id="2507374" data-caption="Baminornis zhenghensis" data-credit="ZHAO Chuang"/>
        </div>
        <figcaption class="ArticleImageCaption">
            <div class="ArticleImageCaption__CaptionWrapper">
                <p class="ArticleImageCaption__Title">Baminornis zhenghensis</p>
                <p class="ArticleImageCaption__Credit">Zhao Chuang</p>
            </div>
        </figcaption>
    </figure>
</p>
<p>Discovered in China, the 150 million-year-old fossil <em>Baminornis zhenghensis</em> raises intriguing questions about the evolutionary link between birds and dinosaurs. Researchers suggest it could be the oldest bird discovered, showcasing shorter tail features than <em>Archaeopteryx</em>, hinting that modern bird characteristics evolved earlier than expected.</p>

<p xmlns:default="http://www.w3.org/2000/svg">
    <figure class="ArticleImage">
        <div class="Image__Wrapper">
            <img class="Image" alt="Joaquinraptor casali" width="1350" height="900" src="https://images.newscientist.com/wp-content/uploads/2025/12/05151937/SEI_267730855.jpg" srcset="https://images.newscientist.com/wp-content/uploads/2025/12/05151937/SEI_267730855.jpg?width=300 300w, https://images.newscientist.com/wp-content/uploads/2025/12/05151937/SEI_267730855.jpg?width=400 400w" sizes="(min-width: 1288px) 837px, (min-width: 1024px) calc(57.5vw + 55px)" loading="lazy" data-image-context="Article" data-image-id="2507375" data-caption="Joaquinraptor casali" data-credit="Andrew McAfee, Carnegie Museum of Natural History"/>
        </div>
        <figcaption class="ArticleImageCaption">
            <div class="ArticleImageCaption__CaptionWrapper">
                <p class="ArticleImageCaption__Title">Joaquinraptor casali</p>
                <p class="ArticleImageCaption__Credit">Andrew McAfee, Carnegie Museum of Natural History</p>
            </div>
        </figcaption>
    </figure>
</p>
<p>The terrifying <em>Joaquinraptor casali</em>, discovered in Patagonia, showcases a unique predator adaptation—its jaw was found with a crocodile's foot lodged in it. With a thumb claw akin to a human forearm, this new <em>Megaraptor</em> species likely grew to over 7 meters long, weighing around 1 tonne, making it one of the fiercest contenders of the Cretaceous period.</p>

<section class="SpecialArticleUnit">
    <picture class="SpecialArticleUnit__ImageWrapper">
        <img class="Image SpecialArticleUnit__Image" alt="Explore the world of science with New Scientist" width="1200" height="800" src="https://images.newscientist.com/wp-content/uploads/2022/07/04143725/istock-622193346-.jpg" srcset="https://images.newscientist.com/wp-content/uploads/2022/07/04143725/istock-622193346-.jpg?width=300 300w, https://images.newscientist.com/wp-content/uploads/2022/07/04143725/istock-622193346-.jpg?width=375 375w" sizes="(min-width: 1277px) 375px, (min-width: 1040px) 26.36vw" loading="lazy" data-image-context="Special Article Unit" data-credit=""/>
    </picture>
    <div class="SpecialArticleUnit__CopyWrapper">
        <h3 class="SpecialArticleUnit__Heading">Dinosaur Hunting in Mongolia's Gobi Desert</h3>
        <div class="SpecialArticleUnit__Copy">
            <p>Join an exhilarating expedition to unearth dinosaur remains in the Gobi Desert, one of the world's premier paleontology sites.</p>
        </div>
    </div>
</section>

<section class="ArticleTopics" data-component-name="article-topics">
    <p class="ArticleTopics__Heading">Topics:</p>
</section>

Source: www.newscientist.com

Jurassic Dinosaur Fossils Illuminate the Evolution of Flight

Posted on December 19, 2025 by

Paleontologists studied fossils that are 160 million years old. Anchiornis Huxley, a non-avian theropod dinosaur, was unearthed from the Late Jurassic Tianjishan Formation in northeastern China. The preserved feathers indicated that these dinosaurs had lost their flying capability. This rare find offers insights into the functions of organisms that existed 160 million years ago and their role in the evolution of flight among dinosaurs and birds.

This fossil of Anchiornis Huxley has nearly complete feathers and coloration preserved, allowing for detailed identification of feather morphology. Image credit: Kiat et al., doi: 10.1038/s42003-025-09019-2.

“This discovery has significant implications, suggesting that the evolution of flight in dinosaurs and birds was more intricate than previously understood,” said paleontologist Yosef Kiat from Tel Aviv University and his team.

“It is possible that some species had rudimentary flight abilities but lost them as they evolved.”

“The lineage of dinosaurs diverged from other reptiles approximately 240 million years ago.”

“Shortly after (on an evolutionary timeline), many dinosaurs began developing feathers, unique structures that are lightweight and strong, made of protein, and primarily used for flight and thermoregulation.”

About 175 million years ago, feathered dinosaurs, known as Penaraputra, emerged as distant ancestors of modern birds; they are the only dinosaur lineage that survived the mass extinction marking the end of the Mesozoic Era 66 million years ago.

As far as we know, the Pennaraputra group developed feathers for flight, but some may have lost that capability due to changing environmental conditions, similar to modern ostriches and penguins.

In this study, the researchers examined nine specimens of a feathered pennaraptorian dinosaur species called Anchiornis Huxley.

This rare paleontological find, along with hundreds of similar fossils, had its feathers remarkably preserved due to the unique conditions present during their fossilization.

Specifically, the nine fossils analyzed were selected because they retained the color of their wing feathers: white with black spots on the tips.

“Feathers take about two to three weeks to grow,” explains Dr. Kiat.

“Once they reach their final size, they detach from the blood vessels that nourished them during growth and become dead material.”

“Over time, birds shed and replace their feathers in a process known as molting, which is crucial for flight.” He notes that birds that depend on flight molt in an organized and gradual manner, maintaining symmetry and allowing them to continue flying during the process.

Conversely, the molting of flightless birds tends to be more random and irregular.

“Molting patterns can indicate whether a winged creature was capable of flight.”

By examining the color of the feathers preserved in dinosaur fossils from China, researchers could reconstruct the wing structure, which featured series of black spots along the edges.

Additionally, newly grown feathers, which had not fully matured, were identifiable by their deviation in black spot patterns.

A detailed analysis of the new feathers in nine fossils revealed an irregular molting process.

“Based on our understanding of contemporary birds, we identified a molting pattern suggesting these dinosaurs were likely flightless,” said Dr. Kiat.

“This is a rare and particularly intriguing discovery. The preservation of feather color offers a unique opportunity to explore the functional characteristics of ancient organisms alongside body structures found in fossilized skeletons and bones.”

“While feather molting might seem like a minor detail, it could significantly alter our understanding of the origins of flight when examined in fossils,” he added.

“Anchiornis Huxley‘s inclusion in the group of feathered dinosaurs that couldn’t fly underscores the complexity and diversity of wing evolution.”

The findings were published in the journal Communication Biology.

_____

Y. Kiat et al. 2025. Wing morphology of Anchiornis Huxley and the evolution of molting strategies in paraavian dinosaurs. Communication Biology August 1633. doi: 10.1038/s42003-025-09019-2

Source: www.sci.news

New Study Confirms Nanotyrannus as a Distinct Species of Tyrannosaurid Dinosaur

Posted on December 9, 2025 by

Nanotyrannus lansensis — For years, many believed these specimens were juvenile tyrannosaurus rex — However, a team of American paleontologists analyzed the ceratobranchia (hyoid bone) and concluded that it was actually a distinct, fully grown small tyrannosaurid. This finding shed light on the growth history of Nanotyrannus lansensis.

Encounter between adults of Nanotyrannus lansensis (left) and two juvenile tyrannosaurus rex, with a sub-adult tyrannosaurus rex watching from a distance. Image credit: Jorge Gonzalez.

Nanotyrannus lansensis measures 5.5 meters (18 feet) tall, which is relatively small compared to its length of over 12 meters (40 feet) compared to tyrannosaurus rex.

Initially discovered in 1942, Nanotyrannus lansensis was first classified as gorgosaurus, but through further scientific investigation, it was redefined as a separate species in 1988.

The main cause of the lengthy debate over the classification is that the holotype consists solely of an isolated skull, while traditional assessments of maturity often rely on limb bones.

Until recently, studies on other more complete fossils of Nanotyrannus lansensis yielded conflicting conclusions.

In a recent study, paleontologist Christopher Griffin from Princeton University and his team discovered that the microstructure of small bones in the throat ceratobranchial can accurately indicate the age and skeletal maturity of fossil specimens.

“At the time, there was a general consensus that the holotype skull of Nanotyrannus represented an immature tyrannosaurus rex rather than a distinct species,” Dr. Griffin stated.

“We initially aimed to follow that consensus, but upon examining samples of the hyoid bone and noticing characteristics strongly indicating maturity, we realized we needed to reevaluate that notion.”

The researchers found that in both modern archosaurs (like ostriches and crocodiles) and extinct theropods, the ceratobranch bones retain unique signals of growth and maturation, making them particularly useful for determining the developmental stage of fully mature individuals.

Using this technique, the team studied the holotype of Nanotyrannus lansensis and analyzed three sections of its ceratobranchia, identifying several features that suggest near-complete skeletal maturity.

This indicates that Nanotyrannus lansensis is a taxonomically distinct species that coexisted with tyrannosaurus rex, suggesting a greater diversity of predators in Late Cretaceous ecosystems than previously understood.

“This smaller-bodied tyrannosaurus rex indicates that the carnivore’s hyoid displayed a growth pattern suggesting it had reached or was close to maturity,” remarked paleontologist Ashley Poust of the University of Nebraska State Museum.

“We can now confidently affirm our classification of Nanotyrannus as separate from tyrannosaurus rex.”

“This implies the presence of at least two carnivores of different sizes in the same environment, which has significant implications for dinosaur ecology and extinction,” he added.

“Understanding what existed helps us gauge the size of the fossil record and how species have evolved over time.”

“Furthermore, it’s crucial to comprehend the complexity of the ecosystem.”

Results from this study are published in the journal Science.

_____

Christopher T. Griffin et al. A small Tyrannosaurus rex lived alongside tyrannosaurus rex. Science published online on December 4, 2025. doi: 10.1126/science.adx8706

Source: www.sci.news

Bolivian Fossil Site Captures Thousands of Cretaceous Dinosaur Footprints, Tail Marks, and Swim Trails

Posted on December 5, 2025 by

The Carreras Pampas archaeological site within Bolivia’s Toro Toro National Park has documented 1,321 tracks and 289 isolated footprints, totaling 16,600 theropod dinosaur footprints. Additionally, 280 swim tracks have been identified, amounting to 1,378 swim tracks in total. Some of the tracks include tail traces.

Dinosaur footprints at the Carreras Pampas Stadium in Bolivia’s Toro Toro National Park. Image credit: Esperante et al., doi: 10.1371/journal.pone.0335973.

Bolivia boasts one of the most comprehensive and diverse records of dinosaur footprints globally, covering the Triassic, Jurassic, and Cretaceous periods.

Despite the abundance of track sites, there has been limited scientific research published.

A recent study led by paleontologist Raul Esperante from the Institute of Geosciences, along with his colleagues, has documented an extraordinary variety of dinosaur footprints at the Carreras Pampas site in Toro Toro National Park.

In nine different study areas, the research team uncovered 16,600 footprints left by three-toed theropod dinosaurs from the late Cretaceous.

These footprints vary in size from small (less than 10 cm) to large (over 30 cm) and capture a range of dinosaur behaviors, including running, swimming, tail dragging, and abrupt turns.

“The waist height of most (80%) of the trackmakers was between 65 cm and 1.15 meters, with a significant portion measuring between 75 cm and 1.05 meters,” stated the paleontologist.

“Interestingly, very few trackmakers exceeded 1.25 meters in height.”

The majority of these footprints are oriented approximately northwest to southeast, and the sediments retain ripple marks, indicating that these dinosaurs traversed ancient shorelines.

“The Carreras Pampas track set a new world record for the number of individual dinosaur footprints, continuous tracks, tail marks, and swimming marks,” the researchers noted.

“This exceptional frequency suggests it was a heavily trafficked area, and the parallel alignment of some footprints may imply groups of dinosaurs traveled together.”

“Numerous more footprints at this site and other locations in Bolivia remain to be studied,” they added.

“This site offers a remarkable glimpse into the region’s past. It reveals not only how many dinosaurs inhabited the area but also their behaviors during migration.”

“It’s truly incredible to work here, as the ground is covered with dinosaur footprints wherever you look.”

The team’s findings were published in the online journal PLoS ONE.

_____

R. Esperante et al. 2025. Morphology, preservation, and taphonomy of dinosaur footprints, tail prints, and swim tracks in the world’s largest athletic arena: Carreras Pampas, Toro Toro National Park, Bolivia (Upper Cretaceous). PLoS One 20 (12): e0335973; doi: 10.1371/journal.pone.0335973

Source: www.sci.news

Paleontologists Uncover New Species of Mamenchisaurid Dinosaur

Posted on December 2, 2025 by

A recently identified sauropod dinosaur, Mamenchisaurus, was discovered in China, originating from the late Jurassic period.

Reconstruction of the life of Mamenchisaurus species, Mamenchisaurus sinocanadorum. Image credit: Júlia d’Oliveira.

Mamenchisaurus sanggensis existed during the early Oxfordian stage of the Jurassic period, approximately 160 million years ago.

This dinosaur belonged to the divergent Mamenchisauridae family, sharing a close relationship with other Mamenchisaurus species.

“The diversity of sauropod dinosaurs peaked in the Late Jurassic, encompassing numerous geographically widespread non-neosauropod eusauropod lineages (like Mamenchisaurs and turiasaurs) alongside a broad array of globally distributed neosauropod members (Diplodocoidea and Macronaria),” stated Dr. Hui Dai, a paleontologist at the Chongqing Institute of Paleontology.

“Late Jurassic sedimentary formations in China preserve a rich sauropod fossil record, predominantly featuring mamenchisaurids, although precise neosauropod remains are largely recognized from the Middle Early Jurassic period.”

“The dominance of sauropod faunas in Asia contrasts sharply with that of contemporary European and North and South American strata.”

“Additionally, most of the late Jurassic Asian sauropod diversity is traced back to deposits from the lower section, particularly around the transition from the Middle to Late Jurassic.”

A partial skeleton of Mamenchisaurus sanggensis was uncovered at a fossil site in Chongqing, located in southwest China.

“The remains were found in reddish-purple silty mudstone near the upper layer of the Shaximyo formation,” paleontologists noted.

“While a general Callovian-Oxford age for this formation has traditionally been assumed, the exact age remains a subject of debate.”

The discovery of Mamenchisaurus sanggensis adds to the diversity of early-branching sauropod dinosaurs and offers further insights into the evolutionary history of sauropods in northwestern China.

“A deeper understanding of the evolutionary relationships among mid to late Jurassic Chinese eusauropods may have implications for testing theories regarding the isolation of East Asia from western Laurasia and Gondwana during this era and for the paleobiogeographic history of early diverging sauropods and more broadly, eusauropods,” the researchers remarked.

“Nonetheless, our knowledge of this evolutionary transition is incomplete, and a reexamination of specimens is essential to bridge the existing ‘gap’ in East Asian lineages.”

The study was published in the Journal on November 25, 2025 in Scientific Reports.

_____

H. Dai et al. A new mamenchisaurid sauropod dinosaur from the Late Jurassic of southwestern China reveals fresh insights into the evolution of East Asian eusauropods. Scientific Reports, published online on November 25, 2025. doi: 10.1038/s41598-025-29995-z

Source: www.sci.news

Ancient Sauropod Dinosaur Footprint, Dating Back 150 Million Years, Found in Colorado

Posted on November 26, 2025 by

Paleontologists conducted an analysis of the path taken by an exceptionally long sauropod at the West Gold Hill Dinosaur Tracking Station in Colorado, USA. Their findings suggest that the massive dinosaurs responsible for it might have exhibited a limp.

Aerial view of the West Gold Hill dinosaur track site in Colorado, USA. Image credit: USDA Forest Service.

Paleontologist Anthony Romilio from the University of Queensland and his team examined over 130 footprints along a 95.5-meter trail that dates back 150 million years.

“This is a remnant from the late Jurassic period, a time when long-necked dinosaurs like diplodocus and camarasaurus thrived across North America,” stated Dr. Romilio.

“This track is particularly special because it forms a complete loop.”

“Although the reason for the dinosaur’s turnaround remains unclear, this trajectory provides a rare chance to analyze how the substantial sauropod executed a sharp turn before returning to its original direction.”

“The scale of the West Gold Hill Dinosaur Track necessitated a novel approach,” remarked Paul Murphy, a paleontologist from the San Diego Museum of Natural History.

“Given the size of the tracks, capturing these footprints from the ground proved to be quite challenging.”

“We utilized a drone to photograph the entire track in high resolution.”

“These images can now be leveraged to create detailed 3D models that can be digitally examined in the lab with millimeter-level accuracy.”

The virtual model reconstructed the sauropod’s movement throughout the entire path.

“It became evident right away that this animal started moving northeast, looped around, and ultimately ended up facing the same direction,” Dr. Romilio explained.

“Within that circular path, we discovered subtle yet consistent indications of its behavior.”

“A notable observation was the variance in width between the left and right footprints, which changed from very narrow to distinctly wide.”

“This transition from narrow to wide footprints suggests that the width may naturally fluctuate as dinosaurs walked. This implies that short segments of seemingly uniform width could misrepresent their typical walking style.”

“We also noted a small but ongoing difference in stride length of roughly 10 cm (4 inches) between the left and right sides.”

“It’s challenging to determine if this signifies a limp or merely a preference for one side.”

“Many extensive dinosaur trails worldwide could benefit from this method to uncover previously hidden behavioral insights.”

The team’s study was published in the journal Geography.

_____

Anthony Romilio et al. 2025. Track by track: West Gold Hill Dinosaur Tracking Site (Upper Jurassic, Bluff Sandstone, Colorado) reveals sauropod rotation and lateralized gait. Geography 5(4):67;doi: 10.3390/geomatics5040067

Source: www.sci.news

Dinosaur Eggshells Aid Paleontologists in Dating Fossil-Rich Rocks

Posted on November 12, 2025 by

Researchers from Stellenbosch University and other institutions utilized advanced uranium-lead (U-Pb) dating along with elemental mapping to analyze traces of uranium and lead in the calcite of fossilized dinosaur eggshells discovered in the United States and Mongolia.

An artist’s reconstruction of a troodontid dinosaur that had just hatched from a fragment of an egg shell. Image credit: Eva Utsukiyouhei.

The ages of numerous fossil remains globally remain uncertain.

Without precise geological age data for fossils, paleontologists face challenges in comprehending the relationships among different species and ecosystems over time and across regions.

Traditionally, they depend on dating minerals like zircon and apatite found alongside fossils, but these minerals are not always available.

Efforts to date fossils such as bones and teeth often lead to ambiguous results.

Dr. Ryan Tucker and his team at Stellenbosch University adopted a novel strategy. They applied advanced U-Pb dating and elemental mapping to identify trace quantities of uranium and lead in the calcite of fossilized dinosaur eggshells.

These isotopes function as a natural clock, enabling scientists to ascertain when an egg was buried.

Studies of dinosaur eggs sourced from Utah in the United States and Mongolia’s Gobi Desert have indicated that the eggshells can accurately reflect their ages to about 5% in comparison to the true ages of volcanic ash.

In Mongolia, researchers have for the first time directly dated a significant area where dinosaur eggs and nests have been preserved, tracing back to approximately 75 million years ago.

“Eggshell calcite is remarkably adaptable,” states Dr. Tucker.

“This introduces a fresh method for dating fossil sites lacking volcanic layers, which has posed a challenge for paleontology for many years.”

By demonstrating that dinosaur eggshells can reliably record geological time, this research bridges biology and earth sciences, providing scientists with a powerful tool for dating fossil remains worldwide.

“Directly dating fossils is a dream for paleontologists,” remarked Dr. Lindsay Zanno, a paleontologist at North Carolina State University and the North Carolina Museum of Natural Sciences.

“With this innovative technology, we can tackle previously insurmountable riddles of dinosaur evolution.”

The team’s study was published in the journal Communication Earth and Environment.

_____

RT Tucker et al. 2025. U-Pb calcite dating of fossil eggshells as an accurate deep-earth chronometer. Communication Earth and Environment 6,872; doi: 10.1038/s43247-025-02895-w

Source: www.sci.news

Orange Lichen Aids Paleontologists in Locating Dinosaur Fossils

Posted on November 5, 2025 by

Lichens, comprising symbiotic fungi and algae (and/or cyanobacteria), are crucial ecological components that inhabit various substrates, including fossils. A recent study highlights their role as biological indicators of fossils in western North America, and demonstrates that they can be identified through remote sensing techniques.

Preferential colonization of dinosaur bones by lichens. Image credit: Pickles et al., doi: 10.1016/j.cub.2025.09.036.

Dr. Brian Pickles from the University of Reading noted, “This research showcases how extant organisms can assist in uncovering ancient life forms.”

“It’s fascinating to realize that these lichens, which essentially represent miniature ecosystems, thrive on the remains of dinosaurs that went extinct over 75 million years ago.”

“Utilizing drone technology to identify spectral signatures in lichens could transform how paleontologists search for fossils.”

In their research, Dr. Pickles and his team identified two lichen species, Rusabschia elegans and Xanthomendoza trachyphylla, which colonized 50% of exposed fossil bones while affecting less than 1% of nearby rock fragments.

This preference can be attributed to the alkaline, calcareous, and porous nature of dinosaur bones that these lichens favor.

“Although the tendency of lichens to thrive on fossil bones has been observed for decades, it has never been quantitatively assessed until now,” stated Dr. Caleb Brown, a researcher at the Royal Tyrrell Museum of Paleontology.

“During our first encounter with a high concentration of exposed fossil bone, such as in a bone bed, our attention often shifts from the bones themselves to the vibrant orange lichen ‘meadows.’

The researchers deployed a drone fitted with specialized sensors to pinpoint lichen-colonized fossils from aerial imagery boasting a resolution of 2.5 cm.

Lichens reveal distinct spectral characteristics, exhibiting lower reflectance in blue wavelengths and increased reflectance in the infrared spectrum.

This innovative method presents considerable benefits for exploration in paleontology, particularly in remote locations where conventional ground surveys are challenging.

This strategy could expedite fossil discoveries while minimizing field expenses and ecological impacts.

The findings are rooted in decades of anecdotal observations made by paleontologists.

In 1980, paleontologist Darren H. Tanke observed that the orange pigmentation of lichens on centrosaurus bones might soon be detectable via satellite. The potential for locating bones using aerial drone technology appears more achievable than ever.

“This drone study sets the foundation for employing aircraft and satellites to map larger expanses,” remarked Dr. Derek Peddle, a researcher at the University of Lethbridge.

“Our newly developed lichen index will aid in fossil identification across vast terrains.”

“It’s exhilarating to merge our imaging technology with the expertise of this international team to enhance dinosaur discovery through remote sensing of lichens.”

The team’s publication appears in this week’s issue of Current Biology.

_____

Brian J. Pickles et al., 2025. Remote sensing of lichens by drone to detect dinosaur bones. Current Biology 35 (21): R1044-R1045; doi: 10.1016/j.cub.2025.09.036

Source: www.sci.news

New Research Uncovers Nanotyrannus as a Unique Dinosaur Lineage

Posted on November 1, 2025 by

Paleontologists investigated a remarkably preserved and nearly mature Tyrannosaurus rex skeleton found in the Hell Creek Formation of Montana. Their findings suggest that this specimen exhibits traits similar to the holotype of Nanotyrannus and confirm that this lineage is distinct from tyrannosaurus.

A pack of Nanotyrannus daringly attacks a young tyrannosaurus rex. Image credit: Anthony Hutchings.

“This fossil turns decades of research on its head,” stated Dr. Lindsay Zanno, a researcher at North Carolina State University and the North Carolina Museum of Natural Sciences.

The researchers utilized tree ring data, spinal fixation, and developmental anatomy to show that the new specimen reached physical maturity at around 20 years.

Skeletal characteristics like larger forelimbs, more teeth, fewer caudal vertebrae, and distinctive skull neural patterns are established early in development and are biologically incompatible with tyrannosaurus rex.

“For Nanotyrannus to develop into a tyrannosaurus rex would contradict everything we know about vertebrate growth. That’s not just unlikely; it’s impossible,” remarked Dr. James Napoli, a researcher at Stony Brook University.

For years, paleontologists have incorrectly modeled tyrannosaurus growth and behavior using Nanotyrannus fossils.

This new evidence indicates that those studies were based on two entirely different species, suggesting that multiple tyrannosaurus species coexisted in the same ecosystem during the last million years before the asteroid impact.

As part of their study, Dr. Zanno and Dr. Napoli analyzed over 200 Tyrannosaurus fossils.

They found one skeleton, previously thought to represent a juvenile tyrannosaurus rex, that differed from the documented species Nanotyrannus lansensis, which is part of the renowned dueling dinosaur fossil.

The authors concluded that this specimen is a new species of Nanotyrannus, named Nanotyrannus letaeus.

The confirmation of Nanotyrannus implies that predator diversity during the final million years of the Cretaceous was far greater than previously understood, indicating that other small dinosaur species may also have been misidentified.

“This discovery provides a more complex and competitive view of the last days of the dinosaurs,” Dr. Zanno mentioned.

“With its massive physique, powerful bite, and stereoscopic vision, tyrannosaurus rex was indeed a fierce predator, but it did not dominate its environment without competition.”

“Darting together were Nanotyrannus — a slimmer, faster, more agile hunter.”

These findings were published in today’s edition of Nature.

_____

LE Zanno and JG Napoli. Nanotyrannus and tyrannosaurus coexisted at the end of the Cretaceous period. Nature published online October 30, 2025. doi: 10.1038/s41586-025-09801-6

Source: www.sci.news

Nanotyrannus: Dinosaur Skeleton Resolves Long-Standing Debate Over ‘Small Tyrannosaurus’ Fossil

Posted on October 30, 2025 by

Artist’s interpretation of the pack Nanotyrannus assailing a young tyrannosaurus

Anthony Hutchings

Fossils previously thought to belong to a juvenile tyrannosaurus rex have been identified as a fully mature carnivore of a distinct species, resolving a long-standing debate in paleontology.

This controversy originated from a skull unearthed in the Hell Creek Formation in Montana during the 1940s, which was initially identified as gorgosaurus. It was later proposed to be a juvenile tyrannosaurus. In 1988, other researchers posited that the fossil represented an adult of a smaller related species, which they designated Nanotyrannus lansensis.

Since then, a number of additional fossils classified as Nanotyrannus have been discovered, although many paleontologists contend that they are merely tyrannosaurus juveniles.

Now, researchers have examined a complete skeleton for the first time, providing compelling evidence that Nanotyrannus is indeed a separate species.

The skeleton is among a pair of specimens known as “Dueling Dinosaurs,” found by private fossil hunters in 2006, which includes a triceratops and what was initially believed to be a juvenile T. rex buried approximately 67 million years ago.

It was only in 2020, when the fossil came into the possession of the North Carolina Museum of Natural Sciences, that paleontologists could conduct a thorough analysis of it.

“Upon receiving the specimen, we recognized it was extraordinary,” remarks Lindsey Zanno from the North Carolina Museum of Natural Science. “We had no inkling it would radically alter decades of research concerning the world’s most renowned dinosaur.”

Mr. Zanno collaborated with his colleagues, including James Naples, a postdoctoral researcher at Stony Brook University in New York. She had initially supported the juvenile tyrannosaurus theory but was compelled to reevaluate her stance based on the findings.

“Nanotyrannus displays unique nerve and sinus patterns, a greater number of teeth, larger hands, and shorter tails. These traits remain consistent as the species develops from juvenile to adult,” she notes.

Lindsay Zanno with the proposed *Nanotyrannuslansensis* skeleton

North Carolina State University

Zanno and Napoli’s examination of the dinosaur’s limb bones confirmed that it was a fully mature specimen, approximately 20 years old, weighing around 700 kilograms and measuring about 5.5 meters in length. “This is roughly one-tenth the weight of an adult human and half the length of a tyrannosaurus,” Zanno explains.

Additionally, Zanno and Napoli reanalyzed 200 tyrannosaur fossils and concluded that another nearly complete skeleton, known as Jane from the Hell Creek Formation, is misclassified as a tyrannosaurid fossil. They propose that Jane is actually a new species within this genus, designated Nanotyrannus letaeus.

“Although we possess only one skeleton of N. Retheus, its anatomy suggests it was part of a larger species,” remarks Zanno. “The configuration of the palatal sinuses and the shape of the bone behind the eye are distinctive.”

Proposed *Nanotyrannus lansensis* skull features more teeth than the *tyrannosaurus* skull.

Matt Zeher/North Carolina Museum of Natural Science

Scott Parsons, a researcher at the South Carolina State Museum, asserts that this latest study clarifies the debate surrounding Nanotyrannus being its own genus and species.

“In my opinion, Nanotyrannus was among the most formidable dinosaur predators, and being pursued by one would be quite a terrifying experience,” Parsons remarks, noting its long legs and fearsome thumb claws.

“In essence, we can compare Nanotyrannus and tyrannosaurus to modern-day cheetahs and lions. While they shared a similar overall anatomy, they had distinct hunting strategies.”

Thomas Carr from Carthage College in Wisconsin has expressed that the new findings are “quite definitive” that the dueling dinosaur specimen represents an almost adult species, one that differs from tyrannosaurus.

Additionally, Holly Ballard from Oklahoma State University, who led the 2020 research, stated that there is “no contention” regarding the team’s conclusion that the fossil belonged to an individual nearing adult size.

However, neither Ballard nor Carr are fully convinced that the other fossil, Jane, constitutes a new species of Nanotyrannus. “Jane is still maturing and large,” emphasizes Ballard, suggesting it may be a new taxon rather than a juvenile tyrannosaurus. “We’re returning to the old debates,” Ballard laments.

“Moreover, in the Hell Creek Formation, if there are numerous small tyrannosaurs in circulation, where are the juvenile tyrannosaurus? ” Kerr questions, stating that it complicates the fossil record. “We simply haven’t uncovered enough tyrannosaurs to fully elucidate what was occurring during the growth phases of the tyrannosaurids in the Hell Creek Formation.”

Dinosaur hunting in Mongolia’s Gobi desert

Embark on an exhilarating and unique expedition to discover dinosaur ruins in the vast wilderness of the Gobi Desert, one of the world’s most renowned paleontology hotspots.

Source: www.newscientist.com

New Sauropod Dinosaur Species Discovered in Museum Collection

Posted on October 30, 2025 by

Fossil brain box and partial skull roof Carnegie Museum of Natural History. This specimen underwent reevaluation and was reclassified, resulting in the establishment of a new genus and species of sauropod dinosaur from the Dicraeosauridae family: athena bellmani.

Holotype brain case of athena bellmani. Image credit: Whitlock et al., doi: 10.26879/1550.

The dinosaur athena bellmani inhabited what is now Utah, USA, during the Late Jurassic Period, approximately 151 to 150 million years ago.

This specimen, designated Carnegie Museum (CM) Specimen 26552, was first discovered in 1913 in the Morrison Formation at the Carnegie Quarry in Dinosaur National Monument.

So far, the specimens have been assigned to a genus of sauropod dinosaurs known as diplodocus.

Dr. John Whitlock, a researcher at Mount Aloysius College and the Carnegie Museum of Natural History, commented, “The Carnegie Museum of Natural History contains some of the most significant specimens for understanding the cranial anatomy of diplodocoid sauropods.”

“One specimen, CM 26552, is frequently overlooked in favor of a more complete skull; however, it holds immense historical significance as it provided the foundation for modern descriptions of brain case anatomy in the diplodocus genus.”

“In view of new discoveries since its initial description in 1978, we are reassessing the anatomical and taxonomic relationships of this specimen.”

The new analysis indicates that CM 26552’s characteristics align more closely with another group of sauropods, the Dicraeosauridae.

“CM 26552 showcases mosaic features that distinctly separate it from other known North American dicraeosaur species,” the paleontologists noted.

“Based on this evidence, we are assigning CM 26552 to a new genus: athena, with the specific name bellmani.”

Research has also revealed that athena bellmani is closely related to dicraeosaurids like Swasea.

The researchers stated, “Considering CM 26552 as a new species of Dicraeosaurina enhances our understanding of this family’s diversity in the Morrison Formation and North America broadly, thus enriching the historically underrepresented sauropod diversity of this region.”

The findings have been published in an online journal this month: Old Trogia Electronica.

_____

John A. Whitlock et al. 2025. athena bellmani, a new species of dicraeosaur sauropod discovered from Dinosaur National Monument in Utah, USA. Old Trogia Electronica 28 (3): a50; doi: 10.26879/1550

Source: www.sci.news

New Dome-Headed Dinosaur Species Discovered in Montana

Posted on October 21, 2025 by

A new genus and species of pachycephalosaur dinosaur has been identified by paleontologists from five fossil specimens found in the Late Cretaceous Two Medicine Formation in Montana, USA.

Reconstructing the life of Brontothorus harmony. Image credit: Connor Ashbridge / CC BY 4.0.

This newly identified dinosaur roamed North America during the late Cretaceous period, approximately 75 million years ago.

Named Brontothorus harmony, this ancient herbivore measured around 3 meters (10 feet) in length.

It is classified within the Pachycephalosauridae, a family of bipedal, dome-headed dinosaurs belonging to the ornithischian clade Pachycephalosauria.

“Pachycephalosaurs are a unique ornithischian clade characterized by distinct morphological features,” stated paleontologist D. Carey Woodruff, Ph.D., from the Philip Patricia Frost Museum of Science and the Museum of the Rocky Mountains, along with colleagues.

“These traits include bipedalism, heterodentary dentition, ossification of the caudal muscular septum, as well as the distinctive thickened frontoparietal dome and decorated skull.”

“Most pachycephalosaurid species are primarily known from cranial remains, making the anatomy, functional morphology, and phylogenetic significance of the frontoparietal dome particularly intriguing for paleontologists.”

“This clade is exclusively identified from Late Cretaceous Asia and western North America, with the latter showcasing a more diverse assemblage of pachycephalosaur species.”

“The oldest North American species is the Santonian variant, Acrotorus odeti, and this group evidently diversified during the middle to late Campanian period, resulting in a wealth of presently recognized species.”

A total of 5 specimens attributed to Brontothorus harmony were unearthed in the Two Medicine Formation located in Glacier County, Montana.

“This new species represents the first pachycephalosaur discovered from the Two Medicine Formation,” the paleontologists noted.

The notable dome structure of Brontothorus harmony positions it as the third largest pachycephalosaur in North America.

“Phylogenetic analyses indicate that this new species is significantly distinct from both Stegoceras and Pachycephalosaurus,” the researchers remarked.

“Thus, this species is not closely related to Stegoceras or Pachycephalosaurus.”

“This discovery not only enhances our understanding of the morphology and diversity of pachycephalosaurs but also highlights that this clade included relatively large species sizes during the early Middle Campanian.”

The finding of Brontothorus harmony is detailed in a paper published on October 9, 2025, in the Zoological Journal of the Linnean Society.

_____

D. Cary Woodruff et al. 2025. The first pachycephalosaurs from the Late Cretaceous Two Medicine Formation: Influence of the Western Interior Seaway on the evolution of North American pachycephalosaurs. Zoological Journal of the Linnean Society 205 (2): zlaf087; doi: 10.1093/zoolinnean/zlaf087

Source: www.sci.news

Paleontologists Uncover New Long-Necked Dinosaur Species from the Triassic Era

Posted on October 17, 2025 by

Paleontologists have discovered a new collection of Triassic fossils at the Quebrada Santo Domingo site in the northern Pre-Cordillera Basin of northwestern Argentina. Among their findings are nearly complete skeletons of a previously unknown sauropod dinosaur species, along with several cynodonts, rhinocosaurs, and aetosaurs.

Huayracursor jaguensis. Image credit: Jorge Blanco.

The newly identified species existed in what is now Argentina during the Carnian period of the late Triassic, approximately 230 million years ago.

Known as Huayracursor jaguensis, this dinosaur was an early and primitive member of the clade sauropodomorpha.

The ancient creature featured a relatively long neck and was larger than many of its contemporaries.

“The Carnian period (237 to 227 million years ago) is significant in the evolution of tetrapods, holding the earliest records of several major clades, including dinosaurs,” stated paleontologist Dr. Martin Hechenleitner of the La Rioja Regional Research Center and CONICET, along with colleagues.

“Following the Carnian pluvial period, dinosaurs faced unprecedented radiation levels and quickly established dominance for the remainder of the Mesozoic era.”

“Most of the earliest records originate from a few well-researched regions in South America, specifically the Izquiguarasto-Villa Union Basin in western Argentina and the Paraná Basin in southern Brazil.”

“These locales have produced a variety of early dinosaurs, encompassing ornithischians, herrerasaurs, theropods, and sauropods.”

“While sauropods are the most taxonomically diverse, the majority (with a few fragmentary exceptions) were small, bipedal, and short-necked.”

“Despite the advances in our understanding of the quadrupedal fauna from the Carnian, no dinosaur-containing groups have arisen outside of traditional classifications.”

Selected bone of the Huayracursor jaguensis holotype. Image credit: Hechenleitner et al., doi: 10.1038/s41586-025-09634-3.

Dr. Hechenleitner and his co-authors uncovered fossilized remains of Huayracursor jaguensis and other Triassic animals in the Santo Domingo formation at Quebrada Santo Domingo, a remote region of the Andes Mountains in La Rioja, northwestern Argentina.

“This newly discovered fauna is the first from the newly characterized northern Pre-Cordillera Basin,” the paleontologists remarked.

“Current findings encompass ceratopsians of the hyperodapedontid family, cynodonts from the traversodontid and probynognathic families, a eurysaurian, and at least two sauropod dinosaurs, indicating a Carnian age.”

“Among the sauropods, Huayracursor jaguensis provides the earliest evidence of concurrent weight gain and neck elongation in sauropods, suggesting that these crucial traits emerged at the dawn of dinosaurs.”

“This discovery enhances our understanding of the diversity and geographic distribution of early dinosaur faunas and illuminates the evolution of sauropods during the Carnian period.”

The findings regarding Huayracursor jaguensis are detailed in a paper published in the journal Nature.

_____

EM Hechenleitner et al. A newly discovered long-necked early dinosaur from the Upper Triassic basin of the Andes. Nature, published online October 15, 2025. doi: 10.1038/s41586-025-09634-3

Source: www.sci.news

Newly Discovered Carnivorous Dinosaur Species from the Triassic Period Identified in Argentina

Posted on October 16, 2025 by

New genus and species of theropod dinosaur named Antebi Sukuri Longs has been reported by a team of researchers from the National University of San Juan, the Bernardino Rivadavia Museum of Natural Sciences, the University of Birmingham, CONICET, and CIGEOBIO.

Reconstruction of Antebi Sukuri Longs. Image credit: Jorge Blanco.

Antebi Sukuri Longs inhabited the Earth during the Carnian period of the late Triassic, approximately 231 to 226 million years ago.

This dinosaur measured about 1.2 meters (4 feet) in length and weighed around 8 to 9 kilograms.

The species represents an early-diverging theropod outside the Neoheteropod group, with functional traits previously believed to be exclusive to that classification surprisingly derived.

“This is among the oldest and most primitive dinosaurs yet discovered,” stated Dr. Ricardo Martinez from San Juan National University and his team.

“The early diversification of dinosaurs triggered significant ecological transformations in terrestrial ecosystems, culminating in the dominance of dinosaurs in tetrapod populations by the Triassic-Jurassic boundary 201 million years ago.”

“Therefore, investigating the early diversification of dinosaurs is crucial for understanding the formation of Mesozoic populations.”

“Nonetheless, the absence of stratigraphically continuous fossil data in different geological formations, where the oldest known dinosaurs (dating from 233 to 227 million years ago) are found, has hindered our comprehension of this early diversification.”

Paleontologists uncovered fossilized remains of Antebi Sukuri Longs—including a partial skeleton and skull—discovered in 2014 within the Izquiguarasto formation in northwestern Argentina.

“Few locations in the world offer such ancient and well-preserved fossils,” Martinez remarked.

“One notable site is the Santa María Formation in Rio Grande do Sul, Brazil, and the other is the Izquiguarasto Formation.”

Antebi Sukuri Longs thrived around 2 million years after Earth’s formation in a warm, arid savannah, experiencing episodes from the Carnian rainy season.

“We demonstrate that dinosaur diversity and abundance in the Iskigualast Formation were greater than previously acknowledged, particularly among smaller herbivores (under 30 kg) and medium-sized predators (30 kg to 200 kg),” the researchers stated.

“This diversification took place in Iskigualast during a transition to semi-arid conditions, but a return to wetter conditions created a gap in the dinosaur record beginning around 229 million years ago.”

“Only 15 million years later, during the mid-Norian period, the abundance and diversity of dinosaurs in the basin rebounded, this time characterized by larger-bodied species.”

“Our findings suggest that early dinosaur diversification was interrupted by climate-induced faunal replacement, at least in southwestern Pangea.”

A paper detailing this discovery was published in this week’s edition of Nature Ecology and Evolution.

_____

RN Martinez et al. Carnian theropods with unexpectedly derived features during the initial radiation of dinosaurs. Nat Ecol Evol published online October 14, 2025. doi: 10.1038/s41559-025-02868-4

Source: www.sci.news

Britain Discovers Europe’s Longest Sauropod Dinosaur Footprint

Posted on October 15, 2025 by

In 2024, a remarkable discovery was made at Dewar’s Farm Quarry, located near Bicester, Oxfordshire, England, where new large sauropod dinosaur footprints were found. This year, palaeontologists from Oxford University, Birmingham University, Liverpool John Moores University, and the Oxford University Museum of Natural History uncovered approximately 200 additional footprints comprising four distinct tracks, including Europe’s longest sauropod dinosaur track.

A 166-million-year-old sauropod dinosaur footprint at Dewar’s Farm Quarry in Oxfordshire, England. Image credit: University of Birmingham.

The four newly discovered tracks at Dewar’s Farm Quarry date back to the Middle Jurassic period, approximately 166 million years ago.

These belong to sauropod dinosaurs, which are characterized as large-bodied, long-necked herbivores. Cetiosaurus.

Among these discoveries is Europe’s longest sauropod dinosaur footprint, extending roughly 220 meters from the first exposed footprint to the last.

Professor Kirsty Edgar from the University of Birmingham commented: “We were thrilled to return to the Dewar’s Farm quarry earlier this year to continue our excavation and unveil further dinosaur footprints.”

“This site in Oxfordshire boasts the largest dinosaur footprint in the UK and is likely the largest dinosaur footprint in the world that has been mapped, considering previous discoveries from the 1990s on the same surface nearby.”

Over seven days, the team faced a much drier and harder surface compared to previous years, concentrating on about 80 very large (up to 1 meter) sauropod footprints that create a remarkable trajectory running roughly north-south across the site.

In addition to the extensive sauropod track, three other shorter tracks were revealed, one of which is a continuation of a trace initially discovered in 2022.

While these findings may not be published continuously, the accumulation of data could lead to even longer orbital patterns.

Minor discoveries at the site included marine invertebrates, plant material, and a crocodile jaw.

Professor Richard Butler from the University of Birmingham stated: “Most of what we comprehend about dinosaurs is derived from their skeletons, but dinosaur footprints and deposits can offer valuable insights into how these creatures lived and the environments they inhabited over 166 million years ago.”

“A significant aspect of this latest excavation involves systematic sampling of the sediments associated with the footprints and those filling the footprints, which are currently under analysis to better understand the environment in which they were formed and how they have been preserved.”

“It is likely that additional footprint surfaces will be uncovered in the coming years, and a comprehensive explanation of their significance, new scientific findings, and potential future conservation of the site will be published soon.”

Source: www.sci.news

Paleontologists Discover New Species of Flat-Headed Herbivorous Dinosaur

Posted on October 7, 2025 by Igor Mitreski

Paleontologists from the United States and the Slovak Republic have identified and named a new genus and species of hadrosaur dinosaur that roamed what is now New Mexico during the Cretaceous period.

Reconstructing the life of Acisresaurus wimani based on the holotype and related species. Image credit: Sergey Krasovskiy.

“Hadrosauridae“, a family of large herbivorous dinosaurs, were once among the most prevalent dinosaurs in the Late Cretaceous terrestrial ecosystems of the Western Interior Basin of North America for nearly 20 million years,” stated paleontologist Sebastian Dalman from Montana State University, along with colleagues from Harrisburg University, Pennsylvania State University, New Mexico Museum of Natural History, and Pavol Josef Shafarik University.

“Known commonly as ‘duck-billed’ dinosaurs, this group displayed remarkable taxonomic diversity and success during the Cretaceous period.”

“In the final 20 million years of the Cretaceous, hadrosaurids spread across the globe, appearing in Africa, Antarctica, Asia, Europe, and the Americas.”

The newly identified species, Acisresaurus wimani, lived during the late Cretaceous period, roughly 75 million years ago.

Fossilized dinosaur bones were uncovered in the geological formations of the Kirtland Formation, located in the A Si Sle Pa Wilderness, situated between Chaco Canyon and the De Na Gin Wilderness in San Juan County, New Mexico.

“The holotype specimen includes a diagnostically incomplete skull, several isolated cranial elements such as the right zygoma, quadrate, and dentary, along with a series of articulated cervical vertebrae,” the researchers noted.

“Besides the holotype, additional specimens from the same layer could also belong to this newly described species, including a well-preserved left dentary, a partial skeleton, and two humeri—one from a large adult and the other from a juvenile.”

In prior research, Acisresaurus wimani was linked to Kritosaurus, an early genus of saurolophine hadrosaurids found in the Kirtland Formation.

Both species share a close relationship within the subfamily Hadrosaurinae, specifically the Saurolophinae.

However, phylogenetic analyses indicate that they are distinct groups existing during the Campanian period of the Cretaceous in southern Laramidia.

“The younger species, Kritosaurus, belongs to the Critosaurini clade, comprising various species from northern Laramidia,” the scientists explained.

“Furthermore, phylogenetic results indicate the existence of a clade that includes Acisresaurus and Naashoibitosaurus, having diverged from Critosaurini in the late Campanian (75 million years ago), alongside two unnamed species in southern Laramidia.”

According to the research team, Naashoibitosaurus and Acisresaurus represent flat-headed saurolophines that could form a new category of hadrosaurids.

“This clade points to the considerable taxonomic diversity of saurolophines, which were prominent herbivorous dinosaurs in southern Laramidia during the final 20 million years of the Cretaceous,” the authors remarked.

“The discovery of a new hadrosaur species in New Mexico reinforces the evidence of latitudinal variation in hadrosaur faunas across Laramidia during the Late Cretaceous.”

The team’s study will be published in the Bulletin of the New Mexico Museum of Natural History and Science.

_____

Sebastian Dalman et al. 2025. A new saurolophine hadrosaurid (Ornithischian: Hadrosauridae) discovered in the Late Cretaceous (Campanian) Hunter Wash Member, Kirtland Formation, San Juan Basin, New Mexico. Bulletin of the New Mexico Museum of Natural History and Science 101

Source: www.sci.news

New Abelisaurid Dinosaur Species Found in Argentina

Posted on October 4, 2025 by Igor Mitreski

Researchers from Argentina, Brazil, and the UK have identified a new genus and species of Abelisaurid Theropod Dinosaur.

Geological map indicating the location of Vitosaura Colozacani in the Los Lanos Formation, La Rioja, Argentina. Image credit: Jiménez Velandia et al., doi: 10.5710/amgh.24.09.2025.3653.

The newly identified dinosaur, Vitosaura Colozacani, existed approximately 80 million years ago during the late Cretaceous period.

This ancient species is part of the Abelisaurid family, a group of carnivorous dinosaurs that predominantly thrived in Gondwana throughout the Cretaceous.

Fossil evidence of this family currently comprises over 25 species, with the most comprehensive and well-preserved findings located in Patagonia, Argentina.

“The Abelisauridae is a clade first established in 1985, known for its distinctive features such as a robust and tall skull, well-protected maxillary and frontal areas, a highly compressed axial skeleton, and reduced forelimbs.”

“The discovery of numerous Abelisaurus species over recent decades, mainly on Gondwana’s landmasses, has significantly enhanced our understanding of this theropod lineage.”

“The Abelisauridae represented the predominant clade of theropod dinosaurs during the Cretaceous in Gondwana, with extensive records found in North Africa, India, and Madagascar, extending even into Laurasia, present-day Central Europe.”

“Beyond these findings, this group was remarkably successful in South America, boasting a rich fossil record.”

Fossilized remains of Vitosaura Colozacani were collected during field excursions in 2009 and 2010 at the Los Llanos Formation in La Rioja, northwest Argentina.

“The theropod remains include the first dorsal center, the second dorsal vertebra, a partial sacrum, left ilium, pubic bone, and other uncertain elements,” the paleontologist noted.

“These specimens were found alongside some post-titanosaur remains.”

Vitosaura Colozacani was a medium-sized Abelisaur measuring approximately 4.5-5.5 m (15-18 feet) in length.

The species inhabited a seasonally semi-arid environment where annual rainfall varied between 230 and 450 mm.

“The discovery of Vitosaura Colozacani expands the geographical range of Abelisaurus within the Campania Formation of the Los Lanos Formation in La Rioja; however, the implications of this new species are limited due to its incompleteness and the state of analysis reflected in various phylogenetic studies focusing on Abelisaurus interactions.”

“We believe further research is necessary to enhance the topological robustness of Abelisauridae phylogeny and to discover new materials that could be allocated to Vitosaura Colozacani to more thoroughly test the phylogenetic hypotheses discussed in our study.”

Research findings were published on October 2, 2025, in the journal Ameguinea.

____

Harold Zimenez Verandia et al. 2025. A new late Cretaceous species of Abelisaurus from the province of La Rioja in northwestern Argentina. Ameguinea 62(5): 1-23; doi: 10.5710/amgh.24.09.2025.3653.

Source: www.sci.news

Discovery of a New Carnivorous Dinosaur Species in Argentina

Posted on September 24, 2025 by Igor Mitreski

A recently identified member of the Megaraptran dinosaur family has been unveiled by a collaborative effort of Argentine and US paleontologists.

Joaquinraptor Casali. Image credit: Andrew McCuffy, Carnegie Museum of Natural History.

This newly discovered dinosaur species inhabited Patagonia, Argentina, during the later stages of the Cretaceous period, approximately 70 to 67 million years ago.

Dubbed Joaquinraptor Casali, these ancient predators were the apex carnivores in the region.

It is a member of the Megaraputra, a lineage of large, clawed carnivorous theropod dinosaurs recognized from Cretaceous deposits across Asia, Australia, and especially South America.

“Megaraptrands were carnivorous theropods characterized by elongated skulls, large claws, and robust forelimbs found in Asia, Australia, and South America,” stated Dr. Lucio Ibilik, a paleontologist at Patagonico de Geología y Paleontología.

“Nevertheless, our comprehension of this group is limited due to the scarcity of complete fossils.”

A well-preserved, partially articulated skeleton of a single Joaquinraptor Casali specimen was uncovered in the Lago Corfue Huapi Formation, situated in the South Central Chubut province of central Patagonia, Argentina.

The specimen comprised numerous dinosaur skulls, anterior limbs, hind legs, ribs, and vertebrae.

Based on the microstructure of the bones, paleontologists propose that the specimen is an adult, albeit possibly not fully matured.

Drawing from other megaraptran remains, they estimate that Joaquinraptor Casali measured about 7 meters in length and weighed over 1,000 kg.

Evidence from sediment suggests this dinosaur thrived in a warm, humid floodplain environment.

“The discovery of bones within the fossilized remains of a crocodilian’s leg pressed against the lower jaw of Joaquinraptor Casali provides insights into its feeding habits, suggesting it may have been a primary predator in its habitat,” the researchers noted.

“However, additional studies are necessary to enhance our understanding of its behavior and ecological role.”

According to scientists, Joaquinraptor Casali and other factions of Megaraputra remained dominant predators in this area of South America, ultimately facing extinction alongside other non-avian dinosaurs at the end of the Cretaceous period.

“It seems that South American megaraptolids achieved larger body sizes (over 7 m in length) than their generally smaller counterparts in Australia (5-6 m),” they added.

“The Patagonian Megaraputrids may have continued to grow throughout their evolutionary history, possibly influenced by the extinction of Carcharodontosaurus during the late Cretaceous.”

“Furthermore, this could have permitted Megaraptorids to fill a niche as apex predators within their ecosystems.”

“Moreover, as suggested by the stratigraphy of the Maastrichtian (likely late Maastrichtian), Joaquinraptor Casali may have survived until the Cretaceous-Paleogene boundary, perishing alongside all other non-avian dinosaurs.”

The discovery of Joaquinraptor Casali has been detailed in a paper published in the journal Nature Communications.

____

lm ibiricu et al. 2025. The latest Cretaceous Megaraptolid Cellopod dinosaurs shed light on the evolution and paleontology of megaraptrans. Nut commune 16, 8298; doi:10.1038/s41467-025-63793-5

Source: www.sci.news

New Species of Dinosaur Discovered Within Crocodile Jaw

Posted on September 23, 2025 by Igor Mitreski

Reconstruction of the artist’s dinosaur Joaquinraptor Casali

Andrew McAfee, Carnegie Museum of Natural History

During the Cretaceous period, South America was a site of significant dinosaur discoveries.

Named the dinosaur species Joaquinraptor Casali, this megaraptor was uncovered in 2019 along the banks of the Liochico River in Patagonia, Argentina. It is believed to have existed just before the mass extinction of non-avian dinosaurs 66 million years ago.

Recently, Lucio Ibiricu from the National Council on Science and Technology Research in Tubat, Argentina, and his team conducted an in-depth analysis of the fossil, revealing unexpected findings in the nearly complete skull.

“A relative humerus, likely belonging to an extinct crocodile, was found between the jaws of Joaquinraptor and was in direct contact with its teeth,” states Ibiricu. “This indicates a unique ecological interaction at the time of death.”

Further investigations of the crocodilian humerus are ongoing to ascertain its size, but initial assessments suggest it is considerable, according to Ibiricu.

In addition to the recovered skull, the excavation yielded vertebrae, feet, two claws, arms, legs, and hands. Notably, the thumb claw—approximately the size of a human forearm—could have been effective for tearing the flesh of its prey, according to Ibiricu.

Fossils of other megaraptors have been discovered across Asia, Australia, and South America. Joaquinraptor was first identified close to the Cretaceous period’s end, and it is among the more complete specimens found.

The thumb claw of the dinosaur

Matt Lamanna

The scientific team concluded that the dinosaur was at least 19 years old at the time of its demise, based on the microstructure of the tibia. It measured approximately 7 meters in length and weighed a minimum of 1 tonne.

Meanwhile, Tyrannosaurus Rex was considerably larger and boasted a massive head, as noted by Ibiricu. Nonetheless, he emphasizes that both species represented apex predators within their respective environments.

Dinosaur Hunting in the Gobi Desert, Mongolia

Experience an exciting and unique expedition that explores the renowned sites of dinosaurs in the vast expanse of the Gobi Desert, a premier paleontological hotspot.

Topics:

Source: www.newscientist.com

Paleontologists Uncover a New Species of Iguanodon Dinosaur

Posted on September 23, 2025 by Igor Mitreski

A collaborative team of paleontologists from Portugal, Italy, the United States, and Belgium has enriched their paleontological records with the identification of a new herbivorous dinosaur species: Cariocecus bocagei.

Cariocecus bocagei. Image credit: Victor Feijó de Carvalho.

Cariocecus bocagei inhabited what is now known as Portugal during the Valemia period of the Cretaceous, approximately 125 million years ago.

This newly identified species belonged to the medium-sized Iguanodon group, which includes robust herbivorous dinosaurs with intricate teeth structures.

“The Iguanodon faction plays a significant role in the herbivorous dinosaur fauna across various ecosystems of the Cretaceous period,” stated Dr. Filippo Bertozzo, a paleontologist at the Royal Institute of Natural Sciences and ci2paleo (Centro de Perebierosia de Nature Ecology, Paleontology of Rehabilitation Therapy).

“At the conclusion of the Jurassic, the Iguanodon factions exhibited limited diversity and body size, with the largest being Camptosaurus.

“These dinosaurs were primarily restricted to the central part of the northern landmass of the Jurassic, which now includes modern-day Wyoming, Tanzania, and Portugal.”

“By the mid-Cretaceous, these clades had achieved a worldwide distribution,” they further commented.

“The selective pressures and environmental factors that drove this diversification during the Jurassic to Cretaceous transition remain poorly understood, largely due to the scarcity of iguanodontian fossils in various regions, such as South Africa.

“The Iguanodon faction was among the first dinosaurs to be discovered and researched, with ongoing studies aimed at exploring the anatomical features and their functions,” they remarked.

“Nonetheless, various aspects of the skull, from the function of the supraorbital bone to paleoneurology and sensory systems, continue to be elusive.”

Digital reconstruction of the skull of Cariocecus bocagei. Image credit: Bertozzo et al., doi: 10.1080/14772019.2025.2536347.

The partial skull of Cariocecus bocagei was uncovered in 2016 along the cliffs of West Portugal from the Paposeco Formation.

This specimen, measuring approximately 37 cm long, is the first Iguanodontian skull recorded in the country.

“The specimen was excavated from the Seco Formation of Papo along the southern coast of the Setubal Peninsula, roughly 200 meters north of Praia de Areia do Mastro,” noted the paleontologist.

“A comprehensive sequence analysis indicates that the early Cretaceous layers found along this coastline were deposited during the fourth and final uplift episodes related to the formation of the Lusitania Basin.”

Upon examining the fossils, researchers identified anatomical characteristics not observed in other Iguanodon species.

“The upper jaw and Jugal bones are flawlessly fused. I have never encountered this in any other iguanodon,” Dr. Bertozzo expressed.

“This isn’t a random anomaly; it’s a genuinely unique feature, confirming it as a new species.”

MicroCT scans enabled scientists to explore the cranial nerves and inner ear with remarkable detail.

“A skull discovery is always significant. It reveals much more than isolated bones,” Dr. Bertozzo commented.

“In this instance, you can observe the impressions of the brain and nerves and even reconstruct parts of the inner ear.”

“The structure of the balance organs and auditory nerves offers insights into how this animal lived and oriented itself.”

“Another notable feature is the unusually low ‘brow’ bones, lower than those of other known Iguanodon factions.”

“This likely supported a heavy brow ridge akin to that of modern eagles.”

“Such structures may have implications for functionality or visibility.”

“The teeth of Cariocecus bocagei also provided remarkable insights,” he added.

“MicroCT scans uncovered not only visible teeth but also replacement teeth embedded within the jaw, designed to replace those that have worn down.”

“This tooth replacement mechanism is characteristic of iguanodons but is rarely observed in earlier species.”

The research team speculates that Cariocecus bocagei may have possessed a stronger bite relative to its kin.

“The discovery of Cariocecus bocagei enhances our understanding of the ecological dynamics within the Lusitania Basin’s early Cretaceous environment, indicating the presence of multiple Iguanodon species, reflecting trends seen in other symbiotic habitats in the UK, Belgium, Spain, and Central Africa,” the authors stated.

“The Valemian diversity in Iguanodon taxa resulted from island endemic events that emerged following the dispersal of dry morphs in North America during the Late Jurassic and Late Cretaceous periods.”

“In conclusion, the discovery of Cariocecus bocagei emphasizes the significance of the Balemian Psien of Hauteribia in the diversification and speciation of Iguanodonians, ultimately leading to the evolution of the more advanced Hadrosaurus in the Turonian period.”

Survey results were published in the Journal of Systematic Palaeontology.

____

Filippo Bertozzo et al. 2025. Cariocecus bocagei, a new basal hadrosauroid from the Lower Cretaceous period of Portugal. Journal of Systematic Palaeontology 23(1); doi:10.1080/14772019.2025.2536347

Source: www.sci.news

The Most Complete and Ancient Dome-Head Dinosaur Fossils Discovered in Mongolia

Posted on September 19, 2025 by Igor Mitreski

Researchers have uncovered the most ancient and well-preserved fossils of Pachycephalosaur, a category of dinosaurs distinguished by their domed skulls in Mongolia. A new study was released in the journal Nature on Wednesday.

The fossils, estimated to be between 108 and 105 million years old, belong to a juvenile of an unidentified species, referred to by scientists as Zavasepharelinpoche.

This discovery took place in the Klen Duk Formation in Mongolia’s Gobi Desert, located between China and Russia, and was led by paleontologist Tsogtbaatar Chinzorig from the Mongolian Academy of Sciences.

There is limited knowledge about these two-legged herbivores from the Cretaceous period, particularly in North America, but they are considered one of the “most enigmatic” dinosaur groups, according to the study. Their unique bone structures and representations in media like Jurassic Park have made them quite popular.

Previous finds of Pachycephalosaur fossils were largely restricted to skulls.

“You could fit all Pachycephalosaurus [fossils] known worldwide into two bathtubs, more or less. There are very few fossil examples,” remarked Michael Pittman, a paleontologist at China University in Hong Kong, in an interview with NBC News.

Fossilized skull of a dome-headed dinosaur from the Cretaceous period.
Alessandro Chiarenza / Via Reuters

The Mongolian discoveries are considered “most skeletally complete,” providing greater insight into the anatomy of Pachycephalosaurus than previously available.

The individuals identified as Zavasephale were at least two years old and measured approximately three feet in length. More than half of its skeleton has been recovered, featuring long legs, short arms, small hands, and gastroliths, or stones ingested to aid in digesting vegetation.

Though these animals were not fully grown, their skeletons showed already thickened bones above the skull.

The integrity of the fossils “will be a key specimen for understanding how the cranial dome of Pachycephalosaurus evolved,” said Chinzorig, based on insights from the National Museum of History in London.

Scientists have proposed that Pachycephalosaurus may have engaged in head-butting behavior or used their domes to attract mates, though the precise function of the dome is still undetermined.

These fossils are approximately 15 million years older than previously found Pachycephalosaurus specimens, enhancing our understanding of dinosaur evolution.

“This is the oldest variety we’ve encountered, thus providing insight into what earlier species looked like and how they evolved over time,” stated Pittman. “The discovery of earlier specimens indicates that they have possessed this dome for quite a while.”

Zavasephale was smaller than later species of Pachycephalosaurs, growing to an estimated length of about 14 feet.

Source: www.nbcnews.com