Paleontologists have discovered a new genus and species of medium-sized Paleasaurus, identified from two fossilized specimens found in China in 2018.
Artist Reconstruction Yinshanosaurus angustus. Image credit: X.-C. Guo, Institute of Vertebrate Paleontology and Paleontology.
The newly recognized species, Yinshanosaurus angustus, existed during the latest Permian period, around 259 to 254 million years ago.
These ancient creatures were part of Paleiasauria, a distinct group of herbivorous tetrapods that thrived across the Supercontinent Pangaea during the Middle Permian.
“Pareiasauria was a bizarre quadrupedal herbivorous clade present during the Guadalpian and Ropingian epochs, significantly impacted by both the late Capitanian and Permian mass extinction events,” stated the Chongqing Institute of Paleontology.
“Fossils of Pareiasauria have been discovered globally, spanning Africa, Europe, Asia, and South America.”
“Pareiasaurus served as a primary herbivorous consumer within various terrestrial tetrapod faunas, including those from the late Permian in northern China.”
“Since the 1960s, eight species of Chinese Paleasaurus have been documented.”
Two significant specimens—a partial post-skull skeleton with a nearly complete skull and another partial skeleton—were excavated in China in 2018.
“The first specimen was found in a dark purple siltstone layer of the Sunjiagou Formation, near Zhangjiage Tuo Village in Bird County, Shanghai,” reported the paleontologist.
“The second specimen was located in purple silty mudstone at the upper section of Member I of the Naobaogou Formation near Qiandian Village in the Siguai district of Baotou, Inner Mongolia.”
According to the researchers, Yinshanosaurus angustus features the narrowest skull of all Pareiasaurus species, with a length over twice its width at the lateral edge of the cheek.
“With the skeleton of Yinshanosaurus angustus, we present the complete skull and detailed post-cranial structure of this Chinese Pareiasaurus for the first time,” they emphasized.
Their study was published this month in the journal Paleontology Papers.
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Jian Yi & Jun Liu. 2025. Tetrapod fauna of the Upper Permian Naobagou Formation in China: A new medium-sized Pareiasaurus Yinshanosaurus angustus and its implications for the phylogenetic relationship of Pareiasaurus. Paleontology Papers 11(3): E70020; doi: 10.1002/spp2.70020
Source: www.sci.news
