Tag Archives: dinosaurs

The Rise of Dinosaurs Told through Fossilized Feces

Posted on by
Reply

A plant-eating sauropod dinosaur that evolved in a humid environment during the early Jurassic period.

Marcin Ambrozik

The contents of feces and vomit from 200 million years ago are helping to show how dinosaurs conquered the world at the beginning of the Jurassic period.

Whole insects embedded in various shapes and sizes of well-preserved plants, bones, fish parts, and even ancient animal feces show that dinosaurs varied in comparison to other groups of animals. This suggests that dinosaurs were able to survive in the ecosystem thanks to their wide-ranging diet. This led to their further growth and eventually led to the establishment of a “land dynasty.” Martin Kvarnström At Uppsala University, Sweden.

Fossil evidence shows that the first dinosaurs had prominent hip joints that placed their legs underneath their bodies like mammals, rather than sprawling sideways like lizards. More than 230 million years ago During the Triassic. For tens of millions of years, these early dinosaurs blended into a landscape filled with many other types of reptiles. But by about 200 million years ago, dinosaurs had essentially taken over the Earth, around the time most other reptiles disappeared during the end-Triassic extinction.

What led to this dominance remains somewhat of a mystery. Kvarnström and his colleagues suspected that important clues might be hidden in the bromalites (fossilized feces and vomit) of dinosaurs and other animals. So they Polish Geological Institute collected by a prior research group from eight locations in Poland between 1996 and 2017.

The research team estimated the age of each bromalite based on the layer of sediment in which it was found, and determined its size, which ranges from a few millimeters to a “fairly large fecal mass,” and the animals that may have produced it. A suitable shape was used. The researchers then 3D scanned the fossil to examine its contents. “We noticed that it was clogged with food debris,” Kvarnström says.

Coprolites, or fossilized feces, of herbivorous dinosaurs containing plant remains

Grzegorz Niedzwicki

Combining the known fossil record and past climate information, researchers determined that the emergence of dinosaurs occurred in several different stages. First, the omnivorous ancestors of early dinosaurs began to outnumber non-dinosaurs. They then evolved into the first carnivorous and plant-eating dinosaurs.

At that point, increased volcanic eruptions and movement of tectonic plates caused flooding and waterway development. The resulting humidity and related changes in climate likely led to a wider range of plants and the evolution of larger and more diverse herbivorous dinosaurs. On the other hand, animals other than dinosaurs (such as dicynodonts, which eat plants weighing up to 1 ton) Lisowisia, Their feces contained mainly coniferous debris and they were less able to adapt to changes in vegetation.

As herbivorous dinosaurs grew larger, so did their predators. By the beginning of the Jurassic period, about 30 million years after the first dinosaurs appeared, the transition to a dinosaur-dominated world was complete, Kvarnström says.

“This study shows how climate primarily affected dominant plants, which created opportunities for new herbivores at certain points in time,” he says. michael benton from the University of Bristol, UK, was not involved in the study.

Although it's difficult to be sure that the researchers matched the scat to the right animal, the discovery nonetheless suggests that the dinosaur species had already expanded significantly in South America before major climate change. This confirms earlier research, he says. “But it took the end-Triassic mass extinction for the final stage of the takeover to begin.”

for emma dunn The study, conducted at Germany's Friedrich-Alexander University, helps answer long-standing questions about the emergence of dinosaurs. “It's not every day that a fossil poop is published in such an influential journal,” said Dunn, who was not involved in the study. “This is obviously interesting, but it's also very useful for understanding prehistoric environments. So if you think of the evolution of early dinosaurs like a jigsaw puzzle with pieces missing, there are new It’s just a lot of pieces thrown in.”

topic:

Source: www.newscientist.com

Hikers and melting snow reveal ancient ecosystem in the Alps before dinosaurs

Posted on by
Reply

Deep beneath the snow-covered slopes lie prehistoric wonders waiting to be discovered. Recently, hikers in the Italian Alps stumbled upon an ancient ecosystem that predates even the dinosaurs, thanks to melting snow.

The groundbreaking discovery was announced on Wednesday, revealing well-preserved reptile and amphibian footprints dating back 280 million years to the Permian period, according to scientists.

Cristiano Dal Sasso, a paleontologist at the Natural History Museum of Milan, described the impressive footprints left by animals at that time, with some measuring 2 to 3 inches long. These fascinating finds are now on display at the museum.

The fossil was unearthed in the mountains of Lombardy, Italy, where the melting snow and ice exposed these ancient treasures due to the ongoing climate crisis.

Researchers move rocks containing fossil footprints in the Italian Alps.
Elio della Ferrera / Milan Museum of Natural History

In the summer of 2023, Claudia Steffensen stumbled upon one of these fossils while hiking in the Valtellina Orobie mountains. This discovery led to a series of investigations by experts like Orsonio Ronchi and Lorenzo Marchetti, unraveling the mysteries of this ancient ecosystem.

Researchers were amazed by the abundance and preservation of the fossils, which provide valuable insights into the Permian period just before the dinosaurs roamed the Earth.

Computer-generated images show what prehistoric reptiles looked like.
Fabio Manucci / Milan Natural History Museum

The rapidly changing climate has played a significant role in revealing these fossils, as rising temperatures have caused snow and ice to melt, exposing the long-hidden remains.

As more footprints and fossils emerge from the mountains in the coming years, researchers warn that studying the past can shed light on the environmental challenges we face today. It serves as a stark reminder of the impact our actions can have on the world.

Source: www.nbcnews.com

Uncovering the Secrets of Dinosaurs: An Interview with David Horn on the Impact of New Technology

Posted on by
Reply
New Scientist. Website and magazine featuring science news and long-form articles covered by expert journalists on developments in science, technology, health and the environment.

Paul Riding/Joseph Woodhouse

Dinosaurs ruled the earth for around 180 million years. But fossils that are at least 65 million years old are incredibly hard to decipher, so we know very little about what these iconic prehistoric creatures lived. Finding out more has long seemed impossible, but not anymore.

Over the past few decades, new techniques and new specimens have provided previously unimaginable insights into the behavior and ecology of dinosaurs. Combined with insights from modern animals, this has finally enabled paleontologists to understand dinosaur biology, from parental care, migration, and hunting styles to communication, sociality, and combat.

David Horne is one of the researchers trying to find out more about life during the time of the dinosaurs: the paleontologist at Queen Mary, University of London, is soon to publish a book about his latest findings. Revealing dinosaur behavior: What they did and how we know. New Scientist From mobile herbivores and semi-aquatic predators to why ostriches are problematic for understanding which dinosaurs doted on their young, here’s some of what’s been discovered so far.

Collin Barrass: Some of the biggest dinosaurs were Diplodocus or BrachiosaurusFor example, dinosaurs were not at all similar to living animals, so how do we figure out how they behaved?

David Horne: One of the most important things we can do as paleontologists is to better utilize our knowledge of the biology and behavior of modern animals. Mouth shapes are a good example. People with small mouths usually target nutritious food, such as shoots and leaves, one by one. If…

Source: www.newscientist.com

Research: Extinction of dinosaurs led to swift evolution of bird genomes

Posted on by
Reply

About 66 million years ago, at the end of the Cretaceous period, a 10 km-wide asteroid struck Earth near what is now the town of Chicxulub in Mexico. The impact wiped out about 75% of Earth's animal and plant species, including groups such as non-avian dinosaurs and ammonites. A new study identifies key changes in bird genomes caused by the end-Cretaceous mass extinction that ultimately contributed to the remarkable diversity of modern birds.

This painting depicts an asteroid impact in the shallow tropical ocean of the sulfur-rich Yucatan Peninsula in what is now southeastern Mexico. The impact of this massive asteroid, which occurred about 65 million years ago, is believed to have wiped out the dinosaurs and many other species on Earth. The painting shows a Pterodactylus, a flying reptile with a wingspan of up to 50 feet, gliding above low tropical clouds. Image by Donald E. Davis/NASA.

“By studying the DNA of modern birds, we can detect patterns in gene sequences that changed shortly after one of the most significant events in Earth's history,” said Dr Jake Barb, from the University of Michigan.

“The signatures of these events appear to be imprinted in the genomes of survivors in ways that are detectable tens of millions of years later.”

An organism's genome is made up of four nucleotide molecules designated by the letters A, T, G, and C. The order of these nucleotides in the genome defines the blueprint of life.

The DNA code can evolve in ways that change the overall composition of DNA nucleotides across the genome.

These changes in composition are important in determining what genetic variations are possible and contribute to an organism's evolutionary potential, or ability to evolve.

Dr. Belf and his colleagues found that the mass extinction caused a change in nucleotide composition.

The researchers also found that these changes appear to be related to the birds' development as young birds, their adult size, and their metabolism.

For example, in the approximately 3 to 5 million years following the mass extinction at the end of the Cretaceous period, surviving bird lineages tended to decrease in body size.

The development of hatchlings has also changed, with more species becoming 'altricial'.

“This means that when they hatch they are still in a fetal state and need to be fed by their parents, and it may take several weeks for them to fledge,” Dr Barb said.

“Birds that are ready to fend for themselves immediately after hatching, like chickens and turkeys, are called 'precocious.'”

“We found that adult body size and pre-hatching developmental patterns are two important traits of bird biology that we can link to the genetic changes we are detecting.”

“One of the most important challenges in evolutionary biology and ornithology is unraveling the relationships between the major bird groups. The structure of the extant bird phylogenetic tree is difficult to determine.”

Over the past 15 years, researchers have been trying to solve this problem by applying increasingly large genomic datasets.

So far, they have used genomic data to study the evolution of bird genomes using statistical models based on strong assumptions.

These traditional models allow researchers to reconstruct the history of genetic change, but they typically assume that the makeup of DNA, i.e. the proportions of A, T, G and C nucleotides, remains constant throughout evolutionary history.

The study authors developed software tools to more closely track DNA composition over time and across different branches of the tree of life.

This tool allowed us to relax the assumption that DNA's composition is constant.

“This allows us to vary our models of DNA evolution across the evolutionary tree and identify places where there may have been changes in DNA makeup,” said Professor Steven Smith, from the University of Michigan.

“In this new study, these changes were clustered within about five million years of the end-Cretaceous mass extinction,” Dr Belff added.

This approach also allowed the team to estimate which bird traits are most closely associated with changes in DNA composition.

“This is an important type of genetic change that we think is associated with mass extinctions,” Dr Barb said.

“To our knowledge, changes in DNA composition have never before been so clearly linked to the end-Cretaceous mass extinction.”

“We know that mass extinctions can have dramatic effects on biodiversity, ecosystems and the forms of life,” said Professor Daniel Field, from the University of Cambridge.

“Our study highlights that these extinction events can have even larger effects on organismal biology by altering key aspects of genome evolution.”

“This study improves our understanding of the dramatic biological impact of mass extinction events and highlights that the mass extinction that wiped out the giant dinosaurs was one of the most biologically consequential events in the entire history of the Earth.”

By relaxing typical assumptions used in evolutionary biology, the researchers are developing more nuanced insights into the sequence of events in birds' early history.

“We haven't typically thought of changes in DNA configurations and models across the tree of life as changes that indicate something interesting happened at a particular time and place,” Prof Smith said.

“This study shows that we've probably missed something.”

of study Published in the journal Scientific advances.

_____

Jacob S. Belf others2024. Genomic and life-history evolution link bird diversification and the end-Cretaceous mass extinction. Scientific advances 10(31); doi: 10.1126/sciadv.adp0114

This article is a version of a press release provided by the University of Michigan.

Source: www.sci.news

7 Dinosaurs that Are Completely Misunderstood by Everyone

Posted on by
Reply

Despite their intimidating appearance, dinosaurs were not slow, lumbering creatures as previously thought. As our knowledge of these prehistoric creatures grows, our early assumptions are being proven wrong. Here are seven significant ways our understanding of dinosaurs has evolved:

1. Tyrannosaurus Rex

In 1902, paleontologist Barnum Brown discovered a massive pile of bones in Hell Creek, Montana. These bones belonged to a towering, bipedal creature with a fierce, predatory look – the Tyrannosaurus Rex. Over the years, numerous T. rex skeletons have been unearthed, revealing it as one of the largest and most powerful carnivorous animals to have lived. Recent discoveries, such as the presence of feathers, suggest T. rex was more complex than originally thought.

Cast of a Tyrannosaurus Rex skeleton on display in the main gallery of the Oxford University Museum of Natural History in Oxford, UK – Image credit: Alamy

2. Iguanodon

In 1822, Gideon Mantell presented a fossil discovered in Sussex, England, to the Royal Society. Initially mistaken for belonging to a giant fish or rhinoceros, the tooth actually belonged to a dinosaur, later named Iguanodon. Subsequent findings have revealed Iguanodon as a giant, ground-dwelling dinosaur with spikes on its hands for defense.

3. Dryptosaurus

Discovered in New Jersey in 1866, Dryptosaurus was one of the first well-preserved carnivorous dinosaur skeletons found in North America. Originally named “Laelaps,” it was later corrected to Dryptosaurus. The predator’s agility and speed challenged old perceptions of dinosaurs as slow-moving creatures.

Dryptosaurus as imagined in 1869 – Image courtesy of Alamy

4. Elasmosaurus

When Elasmosaurus was discovered, its long, snake-like neck puzzled scientists. Initially mistaken for a sea snake-turtle hybrid, it was later identified as a plesiosaur with an unusually long neck, setting it apart from other marine reptiles of its time.

Early studies of Elasmosaurus fossils led some to imagine it was a giant sea snake-turtle hybrid – Image credit: Alamy

5. Stegosaurus

Stegosaurus, known for its distinctive plates, initially puzzled paleontologists due to its unique features. Misinterpreted as an aquatic creature with shell-like plates, subsequent discoveries revealed its upright plates and raised questions about their purpose – whether for display or thermoregulation.

Previous depictions of Stegosaurus were unclear on the plate – Image credit: Alamy

6. Ichthyosaur

Mary Anning’s discoveries in England led to the naming of the Ichthyosaur, an extinct aquatic reptile with flippered limbs and a streamlined body. Initially mistaken for a fish or crocodile, the Ichthyosaur was later recognized as an ancient marine reptile.

Painting “Duria Antiquior” by Henri de la Beche – Image courtesy of Alamy

7. Pterosaur

Pterosaurs, flying reptiles with winged fingers, were initially misunderstood as sea creatures or mammals. Georges Cuvier’s recognition of their wing-supporting fingers led to the understanding of these creatures as early fliers, distinct from dinosaurs but closely related to them.

Early visualizations of pterosaurs made them look almost rodent-like – Image credit: Alamy

Source: www.sciencefocus.com

7 Dinosaurs We All Need to Understand Better

Posted on by
Reply

Dinosaurs were once thought to be big and fearsome creatures, but our understanding of them has changed over time. As we learn more about them, we realize how incorrect our early assumptions were.

Here are seven significant ways our understanding of dinosaurs has evolved…

1. Tyrannosaurus Rex

In 1902, paleontologist Barnum Brown discovered a massive pile of bones in Hell Creek, Montana. These bones belonged to a muscular animal that walked on its hind legs and stood several meters tall. Its skull and jaws portrayed a formidable predator.

The discovery was exhibited at the American Museum of Natural History in 1905, astounding the audience. This monster was called Tyrannosaurus Rex, known as one of the largest and most powerful carnivorous animals to have ever lived on Earth.

Further studies have revealed that T. rex had a large brain, keen senses, and likely had some feathers on its body.

Cast of a Tyrannosaurus Rex skeleton on display in the main gallery of the Oxford University Museum of Natural History in Oxford, UK – Image credit: Alamy

Read more:

2. Iguanodon

In 1822, Gideon Mantell presented fossilized teeth found in Sussex to the Royal Society. These teeth were later recognized as belonging to a dinosaur called Iguanodon. This dinosaur roamed the earth with its spiked hands for self-defense.

Read more:

3. Dryptosaurus

Dryptosaurus as imagined in 1869 – Image courtesy of Alamy

Discovered in the late 1800s in New Jersey, Dryptosaurus was the first well-preserved carnivorous dinosaur skeleton known in North America. It was originally named “Laelaps” but later renamed Dryptosaurus, showcasing its speed, ferocity, and tenacity.

Read more:

4. Elasmosaurus

Early studies of Elasmosaurus fossils led some to imagine it was a giant sea snake-turtle hybrid – Image credit: Alamy

Elasmosaurus, named in the 1860s, had the longest neck of any animal that ever lived. Its skeleton baffled paleontologists for years until a more complete understanding was reached.

5. Stegosaurus

When Stegosaurus bones were first found in the 1870s, they were thought to belong to a strange aquatic creature due to the large vertical plates on its back. Later discoveries revealed a different picture, with some suggesting the plates were for display or thermoregulation.

Previous depictions of Stegosaurus were unclear on the plate – Image credit: Alamy

6. Ichthyosaur

Mary Anning’s discovery of Ichthyosaur fossils in 1811 led to the recognition of these creatures as extinct aquatic reptiles. This marked an important milestone in paleontological understanding.

Painting “Duria Antiquior” by Henri de la Beche – Image courtesy of Alamy

7. Pterosaur

In 1784, the first Pterosaur fossil was discovered, leading to the recognition of these creatures as flying reptiles. They were not dinosaurs but were closely related and the first bony animals to evolve powered flight.

Early visualizations of pterosaurs made them look almost rodent-like – Image credit: Alamy

Read more:

Source: www.sciencefocus.com

How intelligent were the Tyrannosaurus and other giant theropod dinosaurs?

Posted on by
Reply

Large theropods were as intelligent as reptiles, but not as smart as apes, according to a new study led by paleontologists at the University of Bristol.

tyrannosaurus rex Holotype specimen at the Carnegie Museum of Natural History in Pittsburgh, USA. Image credit: Scott Robert Anselmo / CC BY-SA 3.0.

in study Vanderbilt University paleontologist Suzana Herculano-Hausel announced last year that dinosaurs tyrannosaurus It had a huge number of neurons and was much more intelligent than expected.

She argued that these high numbers of neurons could directly inform intelligence, metabolism, and life history. tyrannosaurus In some habits they were more like monkeys.

Theropod dinosaurs of North America from the Late Cretaceous tyrannosaurus “It is an apex predator, one of the largest, heaviest, and most powerful (in terms of bite force) terrestrial carnivores ever known,” said Dr. Heidi George from the University of Bristol.

“Recently, Dr. Herculano Hausel proposed that we should add primate-level intelligence to great apes. tyrannosaurusAlready an impressive predation history, based on high estimates of the number of neurons in the forebrain. ”

“This conclusion arose from the paradigm that neurological variables inferred from endocasts can be used to infer metabolic parameters, behavior, and lifespan of fossil species.”

In the new study, Dr. George and his co-authors took a closer look at the techniques used to predict both brain size and number of neurons in dinosaur brains.

They found that previous assumptions about the size of dinosaur brains and the number of neurons they contained were unreliable.

This new study follows decades of analysis in which paleontologists and biologists studied the size and anatomy of dinosaur brains and used these data to infer behavior and lifestyle.

Information about dinosaur brains comes not only from the shape of the brain cavity itself, but also from its mineral fillings, called endocasts.

The authors found that their brain size, particularly the size of the forebrain, was overestimated, and thus the number of neurons was also overestimated.

Furthermore, we show that estimates of neuron number are not a reliable guide to intelligence.

“To reliably reconstruct the biology of a long-extinct species, researchers need to examine multiple lines of evidence, including skeletal anatomy, bone histology, the behavior of living relatives, and trace fossils.” the researchers said.

“To determine the intelligence of dinosaurs and other extinct animals, it's best to use a wealth of evidence, from gross anatomy to fossilized footprints, rather than relying solely on estimates of neuron counts,” Dr. Heidi said. added.

“We argue that it is not a good idea to predict the intelligence of extinct species when only the number of neurons reconstructed from endocasts is sufficient,” said Dr. Kai Kasper, a paleontologist at Heinrich Heine University. Ta.

“Neuron number is not a good predictor of cognitive ability, and using neuron number to predict intelligence in long-extinct species can lead to very misleading interpretations,” Mikel Crusafont Catalan Paleontologist said Dr. Ornella Bertrand, a paleontologist at the Institute.

“The possibility is that tyrannosaurus The possibility that they were as intelligent as baboons is both fascinating and frightening, and has the potential to transform the way we view our past,” said Dr Darren Naish, a palaeontologist at the University of Southampton. .

“But our study shows how all the data we have contradicts this idea. They were more like smart giant crocodiles, which was just as fascinating. ”

of result Published in anatomical records.

_____

Kai R. Kasper other.How clever! tyrannosaurus• Examine claims about the extraordinary cognitive abilities of dinosaurs and the application of neuron number estimation in paleontological research. anatomical records, published online on April 26, 2024. doi: 10.1002/ar.25459

Source: www.sci.news

Could dinosaurs make a comeback in the future? Insights from a paleontologist

Posted on by
Reply

Dinosaurs, in the form of birds, continue to exist today. However, traditional dinosaurs like tyrannosaurus, triceratops, and stegosaurus, are unlikely to evolve again if the climate and temperatures return to Cretaceous conditions.

While pondering this idea is entertaining, it is impossible to accurately predict future evolutionary developments. Evolution is largely influenced by chance and natural selection, which occurs in response to immediate needs rather than long-term planning.

The late paleontologist Stephen Jay Gould once contemplated rewinding the tape of life to a past era and playing it again. He theorized that each replay would result in a different world, shaped by random quirks and unpredictable paths.

One thing that becomes clear with fossil record analysis is that once a species goes extinct, it is gone forever. Trilobites, for example, have not reappeared despite similarities in today’s climate to theirs in the past.

Evolution through convergence is a powerful force, leading different species to develop similar traits when faced with similar environmental challenges. Therefore, if Earth were to undergo a Cretaceous-like climate shift, it is possible that new large reptiles may evolve, but not necessarily tyrannosaurus and triceratops.

In response to a reader’s question about the possibility of dinosaurs evolving again under different Earth conditions, this article explores the unpredictable nature of evolution and the potential for new species to emerge under changing circumstances.

If you have any questions, please contact us at: questions@sciencefocus.com or reach out on our Facebook or Instagram pages.

Explore more fascinating science topics on our website and stay curious!

Source: www.sciencefocus.com

Cretaceous Dinosaurs with Armored Bodies had Two Cheek Horns

Posted on by
Reply

A new genus and species of ankylosaurid dinosaur have been identified from two specimens discovered in southeastern China.

type specimen of Datai Inliangis Rebuilt on site. The head, neck, and thorax of the specimen were discovered and extracted from a single block. Image credit: Xing other., doi: 10.18435/vamp29396.

named Datai Inliangisthe newly discovered dinosaur species roamed the Earth during the Late Cretaceous period, about 96 million to 90 million years ago.

ancient beast was a member strongosaursa group of club-tailed armored dinosaurs that reached a peak of diversity in the latest Cretaceous period.

“Ankylosaurids are iconic armored dinosaurs that characterized the terrestrial vertebrate fauna of Asia and Laramidia (western North America) during the Late Cretaceous period,” said a paleontologist from the China University of Geosciences. Rida Singh And my colleagues.

“The earliest members of this clade are known from the Early Late Cretaceous of Asia, but there is little consensus on how they relate to anatomically derived and chronologically younger forms. are not obtained.”

“In southeastern China, Cretaceous red sand beds extend into a basin from Zhejiang to Guangdong.”

“However, horizons corresponding to the early Late Cretaceous remain poorly sampled.”

Two well-preserved immature skeletons Datai Inliangis It was collected from the Zhoutian Formation in southeastern China.

The specimens were found combined, with one head placed on top of the other, representing slightly different stages of the ontogeny of the skeleton.

“This is the first definitive vertebrate skeleton, let alone an armored dinosaur skeleton, excavated from the Ganzhou Formation,” the paleontologists said.

According to the authors: Datai Inliangis It is characterized by having two cheekbones/square zygomatic angle.

“The primary horn develops in the posteroventral horn of the skull and projects posterolaterally,” the researchers explained.

“There is a small attached horn just in front of this that hides the jaw joint when viewed from the side.”

“Morphologically, it is intermediate to older Asian ankylosaurids (e.g. crichton pelta and Giyumperta) and derived post-Cenomanian ankylosaurines (e.g. pinacosaurus),” they added.

“Phylogenetic analyzes broadly support this assessment.”

“The new species will either be placed in the Asian ankylosaurine subfamily, which is close to the lineage of the derived taxon, or it will form a sister lineage.” pinacosaurus”

“Based on these insights, Datai This genus represents an important addition to the Early Late Cretaceous vertebrate fauna of southeastern China and highlights the region's future potential for a better understanding of the origins and early evolution of ankylosaurids. ”

of discovery is reported in Vertebrate anatomy, morphology, and paleontology.

_____

L. Shin other. 2024. A new armored dinosaur with double cheek horns that lived in the early Late Cretaceous of southeastern China. Vertebrate anatomy, morphology, and paleontology 11; doi: 10.18435/vamp29396

Source: www.sci.news

Paleontologists Say Early Dinosaurs Thrived and Survived Due to Advances in Motor Skills

Posted on by
Reply

Early dinosaurs were faster and more dynamic than their competitors, according to a study led by University of Bristol researcher Amy Shipley.

By adopting more diverse limb morphologies and styles, dinosaurs may have been able to occupy more terrestrial habitats and greatly diversify extinction events. Image credit: Sergey Krasovskiy.

In their study, Shipley and colleagues compared the limb proportions of a wide range of Triassic reptiles. The Triassic period is the period from 252 million years ago, when dinosaurs first appeared and became famous, to 201 million years ago.

They determined which of these ancient beasts were quadrupedal (quadrupedal) or bipedal (bipedal), and also examined the cursority index, a measure of running ability.

Researchers found that not only were dinosaurs and their relatives bipedal from the beginning, meaning they had limbs adapted for running, but they also We found that it showed a much wider range of running styles. pseudostia.

Pseudonesians also included the ancestors of modern crocodiles. Although there were some small bipedal animals that ate insects, most were medium to large carnivores or herbivores, and they were diverse throughout the Triassic.

The authors believe that dinosaurs and their relatives bird metatarsal maintained a higher range of motor modes throughout this period.

“When the crisis hit 233 million years ago, the dinosaurs won,” Shipley said.

“At that time, the climate changed from wet to dry and there was severe pressure on food.”

“For some reason, dinosaurs, which had been living in small numbers for 20 million years, appeared, but no pseudo-dinosaurs appeared.”

“Like many reptiles and birds today, early dinosaurs may have been good at conserving water.”

“However, our evidence shows that their high adaptability during walking and running played an important role.”

“After the mass extinction at the end of the Triassic period, dinosaurs expanded again,” added Professor Mike Benton from the University of Bristol.

“With the exception of the crocodile ancestors, most of the pseudodinosaurs went extinct in mass extinctions, and we found that these surviving dinosaurs once again expanded their range and took over many of the niches that had been vacated.”

“When we looked at the rate of evolution, we found that dinosaurs were not actually evolving particularly rapidly,” said co-author Dr Armin Elsler, a researcher at the University of Bristol.

“This was a surprise because we expected to see rapid evolution in ornithopods and slower evolution in pseudopods.”

“What this means is that while dinosaur locomotion style was advantageous for dinosaurs, it was not the driving force behind intense evolutionary selection.”

“In other words, when the crisis happened, they were in a better position to take advantage of the opportunities after the crisis.”

“We always think of dinosaurs as large, mobile animals,” says co-author Dr Tom Stubbs, also from the University of Bristol.

“This reminds us that dinosaurs actually started out as nifty little insect-eaters.”

“The first dinosaurs were only a meter long and walked bipedally with their legs raised high. Their leg posture meant they could move quickly and capture prey while fleeing from larger predators. I meant it.”

“And of course, dinosaurs' postural diversity and focus on fast running mean that dinosaurs could diversify given the opportunity,” said co-author Suresh Singh, also from the University of Bristol. the doctor said.

“After the mass extinction at the end of the Triassic period, truly gigantic dinosaurs emerged, over 10 meters long, some with armor, many quadrupedal, but many still bipedal, like their ancestors. Walking.”

“Their diversity of posture and gait means they are highly adaptable, and this ensured their great success for a long time on Earth.”

of study It was published in the magazine Royal Society Open Science.

_____

Amy E. Shipley other. 2024. Archosauromorph migration and early Mesozoic success. R. Soc. Open Science 11(2):231495; doi: 10.1098/rsos.231495

Source: www.sci.news