Scientists Discover Prehistoric Species From Northern China That Lived 259 Million Years Ago

Another prehistoric animal has made its way into the database of researchers, according to the findings of a recent study published in Papers in Palaeontology. The prehistoric animal in question is "Yinshanosaurus angustus," a large plant-eating reptile that roamed the planet around 259 million years ago, as reported by Earth. Experts think that the creature vanished from Earth after the Great Dying. They made the assertion based on insights gathered from fossils unearthed from a purple siltstone in northern China in 2018. It is also the first time a complete skull of a Chinese pareiasaur has been examined and discussed by researchers since 2019. 

Discovery of "Yinshanosaurus angustus"

Experts compared the two specimens dug out from Shanxi and Inner Mongolia. Both were well-preserved, with one being a nearly complete skull and the other an articulated partial postcranial skeleton. The more complete skull measured around ten inches long and four inches wide. It was clear that the specimens belonged to the extinct group of Pareiasauria, which lived in the epochs of Guadalupian and Lopingian, during the Permian period, and were killed due to the Late Capitanian and the end‑Permian mass extinction events. They thrived in ecosystems spreading across South Africa to Russia. This group was essentially a tetrapod that carried a small tail along with a head featuring rings made out of bony knobs. The specimens exhibited some unique features that made researchers conclude that they belonged to a new species altogether. 

Unique Features of the Specimens

The length-width arrangement noted in the specimens had never been noted in any other pareiasaur. It is the narrowest head that has ever been recorded in this group. Other noteworthy features include the snout being as wide as it was long, the frontal bone being slender, and being twice as long as it was wide. The upper-jaw teeth were also found to be vertically arranged, which was not the case for the species' other relatives, where the teeth were tilted backwards. Researchers also observed rear projection on the nasal bone and a notch on the back of the skull.

These features had never been recorded in the same creature to date from Pareiasauria. In the specimens, the paraoccipital process was U-shaped, but in close relatives it was V-shaped. These findings led researchers to conclude that the specimens were a previously unknown species from the group that lived on the northern side of Pangaea. To understand the positioning of this new species in the group's evolutionary tree, 183 anatomical characters were put into a computer program for analysis, which categorized Chinese pareiasaurs into three branches. The new species, named Yinshanosaurus angustus, was placed beside Shihtienfenia completus in a sub‑group.

Importance of this Discovery

Since Yinshanosaurus angustus died during the Great Dying, researchers believe it could reflect how creatures responded to the event. The fossils could indicate what adaptations worked and what didn't. The Great Dying happened due to volcanic eruptions in Siberia, leading to carbon dioxide emissions and global warming. There is a possibility that something like this happens again. Such discoveries could help experts suggest crucial strategies to safeguard humanity, and as much of the world as possible.