New specimen of Triassurus and the early evolution of salamanders

[DD1991]

A new exciting paper regarding early lissamphibian evolution is available online:

 

Rainer R. Schoch; Ralf Werneburg; Sebastian Voigt (2020). A Triassic stem-salamander from Kyrgyzstan and the origin of salamanders. Proceedings of the National Academy of Sciences of the United States of America 117. doi:10.1073/pnas.2001424117. https://www.pnas.org/content/early/2020/05/05/2001424117

 

For a long time, a bonafide salamander from the Triassic remained elusive in the fossil record, although the recent description of Chinlestegophis has helped shed light on early caecilian evolution. Triassurus had been assigned to Caudata by Ivakhnenko (1978), but Estes (1981) questioned this placement and viewed it as a larval temnospondyl, while Milner (1994, 2000) noted that Triassurus has a suite of traits that distinguish it from Jurassic salamanders. Now, however, the paper by Schoch et al. confirms the initial placement of Triassurus as a member of Caudata, effectively making that genus the earliest bonafide salamander and filling another gap in the fossil record of early lissamphibians. Additionally, the new specimen of Triassurus happens to further confirm the temnospondyl origin of lissamphibians by sharing physical features with branchiosaurids and amphibamiforms.