Skip to main content
Dryad

Fossil snakes from the Eocene of India: New material with comments on phylogenetic relations and biogeographic and palaeoecological implications

Data files

Jan 21, 2025 version files 9.13 KB

Abstract

Eocene snakes of India have the potential to shed light on the nature of snake diversification on the subcontinent following the Deccan volcanism at the Cretaceous–Paleogene boundary (K-Pg), when India was still a northward drifting isolated landmass prior to its collision with Asia. Here we report a diverse snake fauna from the Eocene of Kutch, western India. The fauna, dominated by aquatic forms, include palaeophiids, a giant madtsoiid and a possible nigerophiid. The palaeophiids from the middle Eocene (late Lutetian) comprise ?Palaeophis and Pterosphenus rannensis sp. nov. Together, these taxa enrich the record of fossil snakes the poorly known late Lutetian of India and represent the youngest record of Palaeophiidae from the Indian subcontinent. Pt. rannensis shows intermediate morphology between Palaeophis and Pterosphenus-grade snakes, and is phylogenetically the earliest-diverging member of Pterosphenus. Additionally, the middle Eocene Pt. biswasi is reassessed and retained as a valid taxon based on pterapophyseal morphology and overall form. Biogeographic considerations highlight the importance of Indian fossil record in understanding the origin and diversification of the genus Pterosphenus. The prevalence of niche partitioning is suggested for the palaeophiids, with Pt. rannensis recovered from a tidal setting and ?Palaeophis sp. from a marsh/swamp setting. The new Indian madtsoiid from the middle Eocene (early Lutetian) represents a sympatric taxon with the terrestrial/semi-aquatic giant Vasuki indicus co-existing in a back swamp marsh setting. The early Eocene (Ypresian) nigerophiid is among the oldest Cenozoic occurrences of this family globally.