A diverse snake fauna has been described from the early Eocene Cambay Formation of the Vastan lignite mine, Gujarat, western India, among which early colubroid caenophidians were the most remarkable. Here we describe a new snake assemblage from the approximately contemporary nearby Tadkeshwar mine situated about 10 km southwest of Vastan. As at Vastan, the material from Tadkeshwar is represented only by vertebrae. There are several species in common with Vastan, such as the small madtsoiid gen. et sp. indet. that possesses a haemal keel, the co-occurring palaeophiids Palaeophis sp. and Pterosphenus sp., the same indeterminate boid, and Thaumastophis missiaeni (Caenophidia incertae sedis). However, the most abundant snakes in Tadkeshwar are the madtsoiids. Among them is a new giant madtsoiid that exhibits morphology broadly similar to Gigantophis and Madtsoia. However, it differs in having dorso-ventrally compressed vertebrae with oval cotyles and condyles and a strong notch on the posterior part of the neural arch. The major axis of the prezygapophysis is transverse in dorsal aspect and the parapophysis is very developed and extends beyond the lateral extremity of the prezygapophysis. The haemal keel is absent. While the composition of the Tadkeshwar fauna, like that from Vastan, is reminiscent of the early Eocene of Europe,
the large madtsoiid suggests a Gondwanan paleogeographic origin. Indeed, such large madtsoiids are known only from the Late Cretaceous and Paleogene of South America, Africa and the Indian subcontinent, and the late Paleogene and Neogene of Australia. More importantly, the snake assemblage from Tadkeshwar indicates that Laurasian taxa of European affinities were still mixed with relict taxa from Gondwana during the early Eocene before or near the India-Asia collision.
Grant Information
National Geographic Society, Leakey Foundation, Wadia Institute of Himalayan Geology, Belgian Science Policy Office