Fieldwork in the lowermost Triassic Panchet Formation of India sheds light on the early archosauromorph radiation

67. EZCURRA M.D., BANDYOPADHYAY S., BUTLER R.J., SENGUPTA D., SEN K., SOOKIAS R.B., NESBITT S.J.

Congreso; The Palaeontological Association 64th Annual Meeting; 2020

Proterosuchidae represents the oldest diversification of Archosauromorpha and the genusProterosuchus is the first new taxon to appear in the Karoo beds of South Africa after thePermian?Triassic boundary. Thus, the diversity of Proterosuchidae plays a key role inunderstanding the biotic recovery after the mass extinction. The taxonomic content of thisclade is currently limited to five species of the latest Permian of Russia and the Induan ofSouth Africa and China. In addition, a few isolated proterosuchid bones have also beenreported in the Induan Panchet Formation of India. Thus, we conducted fieldwork inthis unit to expand our knowledge of the Panchet proterosuchid. We collected multiplevertebrate specimens, including several proterosuchid bones, mostly vertebrae. ThePanchet proterosuchid possesses a unique combination of character states, indicating that itrepresents a new species. The new proterosuchid taxon shares apomorphies with the Early Triassic Russian species Chasmatosuchus rossicus and Chasmatosuchus magnus, whichare absent in other proterosuchids. A phylogenetic analysis recovered these three specieswithin Proterosuchidae, closer to each other than to other proterosuchids. Thus, thetaxonomic diversity of Proterosuchidae is substantially expanded here, indicating a broaderdiversification of the clade in the immediate aftermath of the mass extinction.