A team of paleontologists recently identified a new species of nothosaurid. The small and stocky marine reptile evolved during the Triassic period around 240 million years ago. Details of the study are published in the Journal of Vertebrate Paleontology.
Prehistoric marine reptile
A few months ago, paleontologists from the Chinese Academy of Sciences and the Canadian Museum of Nature came across two similar, near-complete, small fossils in a quarry in Fuyuan County, southwest China. They immediately understood that they were nothosaurids, an extinct family of marine reptiles that lived in the Triassic period between 252 and 200 million years ago.
Due to their size, the researchers initially thought that these fossils belonged to juvenile nothosaurs. Further analysis finally revealed that they were adults and that they represented a whole new species.
Nicknamed Brevicaudosaurus jiyangshanensis, this ancient reptile is thought to have lived around 240 million years ago. At that time, Earth was naturally very different. Most of today’s continents were still grouped. Oxygen levels were also significantly lower due to a mass extinction twelve million years earlier that destroyed many land plants. The dinosaurs, for their part, we’re only beginning to emerge.
For those interested, note that there is an interactive map allowing you to see where your address was at that time. You can also go back as far as 750 million years ago.
Small and stocky
Coming back to our reptile, B. jiyangshanensis used its short, flat tail to float and maintain its balance in shallow water, in search of small prey. Also, the reptile’s bones were visibly very thick and dense, which must have limited its ability to swim quickly but increased its stability underwater.
Based on the analysis of its ribs, the reptile also seemed to benefit from a large pair of lungs. We know that nothosaurids needed to come to the surface to breathe oxygen. Also, this one could likely stay a little longer than the others underwater.
The lead author of the study, Dr. Qing-Hua Shang, points out that the forelimbs of Brevicaudosaurus jiyangshanensis were also more strongly developed than its hindlimbs. According to the researcher, the reptile was probably leaning on it to evolve in its environment.
Finally, B. jiyangshanensis presented a stirrup – the innermost of the bones in the chain of the three ear ossicles – particularly thick and elongated. In other words, it suggests that he enjoyed good hearing underwater. “This small, slow-swimming marine reptile probably had to maintain its vigilance to avoid large predators, while it hunted itself in shallow water,” the researchers conclude.
