Ancient Long-Necked Marine Reptiles Discovered in China

The remarkably long neck of Lijangosaurus johnschengensis. The research team, led by paleontologists from the Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, identified 42 cervical vertebrae at the site.

Reconstruction of nososaurs from approximately 240 million years ago showcases previously hidden diversity in southwestern China: Lijangosaurus johnschengensis (center), Nososaurus janjuanensis (top left), Nososaurus luopingensis (top right), Brevicaudosaurus janshanensis (bottom left), and Lariosaurus hongoensis (bottom right). Image credit: Kelai Li.

Lijangosaurus johnschengensis thrived in the mid-Triassic oceans between 247 and 241 million years ago.

The following ancient creatures belong to the Notosaurus clade of marine sauropterygian reptiles.

Nososaurs could reach lengths of up to 7 meters (23 feet) and swam using four paddle-like limbs.

They possessed flat skulls with a network of slender conical teeth specialized for catching fish and squid.

“Sauropterygia emerged as a dominant marine reptile clade in the Early to Middle Triassic, maintaining its significance for approximately 180 million years within the Mesozoic marine ecosystem,” stated lead author Dr. Xiang Qinghua and colleagues.

“Early diverging sauropterygians include placodonts, pachysaurids, nososaurs, and early pistosaurs.”

“The iconic group known as plesiosaurs represents a clade that diverged later from pistosaurs within the suborder Pterosauria.”

“Nososauridae represents the systematic paleontological equivalent of nososaurids and encompasses more than just nososaurids (nososaurus and lariosaurus) as well as other nososaur species.”

“Although numerous species have been described, nososaurs show low diversity at the genus level and in anatomical morphology relative to other sauropterygian subgroups.”

“Typically, nososaurs are larger than pachypleurosaurs but smaller than pistosaurs, including plesiosaurs.”

The skull of Lijangosaurus johnschengensis was small, while its body extended over 2.5 meters (8 feet) in length.

It evolved an extraordinarily long neck with 42 cervical vertebrae, twice the number seen in most sauropterygians of its time.

“Plesiosaurs are generally recognized for their surprisingly long necks,” noted the paleontologists.

“Despite some late-diverging plesiosaur species exhibiting short necks, early plesiosaurs and their Triassic ancestors, early pistosaurs, featured impressively elongated necks with more than 30 cervical vertebrae, indicating a conformational lineage between early pistosaurs and plesiosaurs.”

“In line with this traditional understanding, we consider only necks with more than 30 cervical vertebrae as long or elongated necks in our research.”

“This distinctive feature of plesiosaurs is unmatched among secondary marine quadrupeds; in contrast, other leading marine animals like ichthyosaurs, thalatoids, mosasaurs, and cetaceans typically possess shorter necks and exhibit more fish-like traits.”

The fossilized skeleton of Lijangosaurus johnschengensis was unearthed in a previously unidentified Early Middle Triassic zone of the Beiya Formation in Yunnan Province, China, near the eastern Tibetan Plateau and northern Myanmar.

“This location differs from previously documented fossil-rich regions in southwestern China along the Yunnan-Guizhou border,” the researchers remarked.

Lijangosaurus johnschengensis marks the earliest known instance of a sauropterygian reptile with an exceptionally long neck featuring 42 cervical vertebrae.

“Our findings demonstrate that extreme cervical elongation, defined as possessing more than 30 cervical vertebrae, emerged in sauropterygians prior to the arrival of plesiosaurs and their pterosaur ancestors,” the scientists concluded.

“Moreover, Lijangosaurus johnschengensis shows a unique type of accessory facet joint differing from other reptiles, which is believed to reduce body undulation.”

“This discovery enhances our understanding of the variety of accessory facet joints in reptiles and underscores the high degree of spinal flexibility during the early evolution of sauropterygians.”

The team’s paper is published in the journal Communications Biology.

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W. Wang et al. 2025. The oldest long-necked sauropterygians, Lijangosaurus johnschengensis: Plasticity of vertebral evolution in sauropterygian marine reptiles. Communications Biology August 1551. doi: 10.1038/s42003-025-08911-1

Source: www.sci.news

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

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.

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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

Identification of a newly discovered species of long-necked marine reptiles from the Triassic era in China.

Paleontologists have identified a new genus and species of small dinophalosaurid archosauromorph from a fossilized skeleton found in China’s Yunnan province.



Holotype of Austronaga Minuta Most of the caudal vertebrae, which were found in looping in Yunnan Province, China, were found, and preserved in the skull, anterior cervical spine, and blocks. Image credit: Wang et al. , doi: 10.19615/j.cnki.2096-9899.231013.

Austronaga Minuta lived in the Thetis Sea during the Middle Triassic period around 244 million years ago.

This new species is an Archosauromorph, a member of a group that contains all forms more closely related to it (such as Crocodilians and dinosaurs, etc.) than Lepidosaurs.

Ancient reptiles are sister species Dinocephalosaurus orientalis, another amazing marine reptile from the Triassic period in central China.

“The Medium Triassic in southern China has produced a prominent marine vertebrate assembly that dramatically alters the understanding of the Tethys Sea and its coastline biota,” says Vertebrate paleontology and paleontology. A colleague and colleague at the institute said. National Geopark.

“The Triassic non-quadrilateral alxaulmorph group holds an important position in these findings.”

“They were traditionally called prototrosauria or prototrosaurs, but are now considered paraphrasing groups.”

“One species belonging to this group of reptiles, Dinocephalosaurus orientalis one of the most interesting reptiles discovered in recent years from the Triassic period in southern China,” they added.

“Its very elongated neck reminds me of a similar condition as seen in the ausauromorph, another aquatic creature. Tanistrophius. ”

“Both species have more than twice the necks as the trunk.”

“Yunnan’s new non-crocodile Archosauromorph shares many features Dinocephalosaurus And along with the latter, it can be distinguished from other long-necked Archosauromorphs. ”

“However, this new species also exhibits many different anatomical features. Dinocephalosaurus therefore, new genus and species have been proposed. ”

A small but mature skeletal specimen of Austronaga Minuta was recovered from the Guanling Formation in Waina village in Yunnan Province, southwestern China.

“The specimen is very compacted, but contains almost completely completely complete, with the anterior part of the skull joint with the skull, and most of the caudal tail of about 60.” The paleontologist said.

Their phylogenetic analysis shows that Austronaga Minuta With Dinocephalosaurus and Pektden It forms a clade representing the Dinocephalosauridae of the Archosauromorph family.

New marine reptiles probably had an aquatic or semi-aquatic lifestyle.

“The dentition Austronaga It's less specialized than that Tanistrophius and Dinocephalosaurus yet they have enlarged teeth like these species. This corresponds to the food possibilities of small aquatic animals, such as fish and cephalopods,” the researchers said.

“Other potential indicators for aquatic movement are Austronaga. ”

“The elaborate structure of the caudal neural spines and chevrons is only observed in Austronaga and Dinocephalosaurus Among these non-crocopodan alxaulmorphs. ”

“These structures of the tail are not essential for aquatic propulsion, taking into account the absence of other aquatic reptiles and even some aquatic lines.”

“Nevertheless, similar morphology converges in many aquatic reptiles: caudal neural spines like plates have been developed in basal fishy disease. Sclerocormus and Chaohusaurus. ”

“The T-shaped chevron is found in the mysterious Zauroptari horn Atopodentatus and with primitive placedonts Paraplacodos and Placodus. ”

“Therefore, we consider the morphology of the caudal vertebrae. Austronaga Suitable for aquatic or at least semi-aquatic animals. ”

Findings are reported in a paper In the journal Palasiatica spine.

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W. Wang et al. 2024. A small dinophalosaurid archosauromorph from the Triassic period in central Yunnan Province, southwestern China. Palasiatica spine 62(1):13-32; doi:10.19615/j.cnki.2096-9899.231013

Source: www.sci.news