Despite their rarity today, rhynchocephalians formed a diverse Early Mesozoic clade with a comparatively good fossil record. They had a Pangaean distribution in the Late Triassic and Early Jurassic, although the Gondwanan record remains more limited than the Laurasian one. We report here on new sphenodontian material from the Jurassic Kota Formation of peninsular India. Two taxa are represented, and both are attributed t o new genera. One is a relatively derived sphenodontian with a premaxillary morphology similar to that of the Late Triassic/ Early Jurassic genus Cleuosaums. The other is somewhat more primitive in its morphology, although clearly a crown-group sphenodontian. In addition, three dentary fragments and a partial maxilla signal the presence of a primitive pleurodont lepidosauromorph similar t o the basal rhynchocephalians Gephyrosaurus and Diphydontosaurus from Britain.
The conventional view of a post-Turonian initiation and a prolonged duration of 50 Ma (exten ding up to Early Oligocene) for the Deccan volcanic activity is discarded in the light of new palaeontolo gical data from the infra-and intertrappean beds of peninsular India. The fish and molluscan fauna and the plant fossils, which were the basis for the above conclusion, are found to be unreliable for establishing tem poral relationships. It has also been demonstrated that dinosaurs, which were considered to have become extinct by the time of intertrappean deposition, do occur in the intertrappen beds. Latest palaeontological evidence from different groups of vertebrates, invertebrates, and palynofossils recovered from the infra
Extensive work done in the last decade on the sedimentary beds intercalated with the Deccan volcanic flows (infra-and intertrappean) has demonstrated the vast potential of these rocks for vertebrate, invertebrate and plant fossils. The infra-and intertrappean beds, especially those exposed on the eastern margin of the Deccan Traps, produced a large number of fossils which made it possible to establish the age and duration of Deccan volcanism (late Cretaceous -early Palaeocene) with some degree of confidence. Affinities of the late Cretaceous infratrappean vertebrates, such as pelomedusid turtles and sauropod dinosaurs, lie with those of Gondwanan landmasses. It seems more likely that these taxa are relicts of the Gondwanan stock that boarded the Indian plate well before its separation from Madagascar 70-80 Ma ago. Remnants of the former Gondwanaland fauna, such as pelomedusid turtles, leptodactylid frogs and titanosaurid dinosaurs did persist in relatively younger (latest Cretaceous) intertrappean beds. In addition to these Gondwanan elements, the intertrappean beds register many North American, European and Central Asiatic taxa (pelobatid and discoglossid frogs, anguid lizards, alligatorid crocodiles, palaeoryctid mammals, ostracodes and charophytes) suggesting that a contact between India and southern Asia was already established by the end of Cretaceous. An early India/Asia collision, long before the widely accepted early to middle Eocene date, is favoured to explain the presence of Laurasian elements in the late Cretaceous of India.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.