An armoured marine reptile from the Early Triassic of South China and its phylogenetic and evolutionary implications

作者：Andrzej S. Wolniewicz, Yuefeng Shen, Qiang Li, Yuanyuan Sun, Yu Qiao, Yajie Chen, Yiwei Hu, Jun Liu · 发表于：eLife · 年份：2023 · DOI：10.7554/elife.83163 · 被引用次数：29 · 研究领域：Paleontology and Evolutionary Biology、Ichthyology and Marine Biology、Evolution and Paleontology Studies

Sauropterygia was a taxonomically and ecomorphologically diverse clade of Mesozoic marine reptiles spanning the Early Triassic to the Late Cretaceous. Sauropterygians are traditionally divided into two groups representing two markedly different body plans – the short-necked, durophagous Placodontia and the long-necked Eosauropterygia – whereas Saurosphargidae, a small clade of armoured marine reptiles, is generally considered as the sauropterygian sister-group. However, the early evolutionary history of sauropterygians and their phylogenetic relationships with other groups within Diapsida are still incompletely understood. Here, we report a new saurosphargid from the Early Triassic (Olenekian) of South China – Prosaurosphargis yingzishanensis gen. et sp. nov. – representing the earliest known occurrence of the clade. An updated phylogenetic analysis focussing on the interrelationships among diapsid reptiles recovers saurosphargids as nested within sauropterygians, forming a clade with eosauropterygians to the exclusion of placodonts. Furthermore, a clade comprising Eusaurosphargis and Palatodonta is recovered as the sauropterygian sister-group within Sauropterygomorpha tax. nov. The phylogenetic position of several Early and Middle Triassic sauropterygians of previously uncertain phylogenetic affinity, such as Atopodentatus , Hanosaurus , Majiashanosaurus, and Corosaurus , is also clarified, elucidating the early evolutionary assembly of the sauropterygian body plan. Finally,...