The first specimen with skin preserved of Lariosaurus (Eusauropterygia) from the Middle Triassic of Monte San Giorgio (Switzerland) allows inferences about its swimming method

A virtually complete specimen of Lariosaurus valceresii, the first of its kind with preserved skin, has been discovered in the UNESCO World Heritage Site of Monte San Giorgio. This rare find reveals that the hands and feet were webbed, suggesting a paraxial, otariid-like swimming method for rapid acceleration. The carbon-film-preserved skin outlines the body and limbs, providing insights into the muscular structure and swimming mechanics of this eosauropterygian nothosauroid from the Middle Triassic. This discovery sheds new light on the evolutionary adaptations of aquatic reptiles during the Triassic period.

Renesto, S., Ragni, C., & Magnani, F. (2025). The first specimen with skin preserved of Lariosaurus (Eusauropterygia) from the Middle Triassic of Monte San Giorgio (Switzerland) allows inferences about its swimming method. Swiss Journal of Palaeontology, 144(1). https://doi.org/10.1186/s13358-025-00396-z