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    Omkar Verma

    Vertebrate fossils have been known from South India's Cauvery Basin since the 1840s, but records of marine vertebrates from the late Albian to Turonian Karai Formation have been limited to a single set of ichthyosaur remains. Recent... more
    Vertebrate fossils have been known from South India's Cauvery Basin since the 1840s, but records of marine vertebrates from the late Albian to Turonian Karai Formation have been limited to a single set of ichthyosaur remains. Recent surface collecting and sieving of lower Cenomanian glauconitic mudstones has yielded the first ichthyosaur material reported in India over the last 140 years, as well as a diverse and previously unrecorded shark assemblage. The ichthyosaur material, including several teeth and vertebrae, is assigned to the sole described Cretaceous genus Platypterygius and to the species P. indicus (Lydekker, 1879). Eight species of shark (one squaliformes, two hexanchiformes, and five lamniformes) are recorded. A new hexanchiform genus Gladioserratus is erected, and two new species (Gladioserratus magnus, gen. et sp. nov., and Dwardius sudindicus, sp. nov.) are named. Many of the shark genera within this largely species-level endemic fauna are known from high paleolatitudes elsewhere, with many showing an antitropical distribution, but are absent in Tethyan areas. This first description of the Karai Formation marine fauna documents the previously unappreciated diversity and unique character of India's Cretaceous marine vertebrates, and indicates a cool-water paleoenvironment for the marine vertebrate assemblage.
    Although a very high invertebrate faunal diversity is known from the outcrops of the Ariyalur group in the Cauvery Basin, southern India, little is known about its vertebrate fauna. Recent fieldwork in the badland exposures of the Karai... more
    Although a very high invertebrate faunal diversity is known from the outcrops of the Ariyalur group in the Cauvery Basin, southern India, little is known about its vertebrate fauna. Recent fieldwork in the badland exposures of the Karai Formation (Upper Cenomanian–Lower Turonian) near Garudamangalam in the basin has yielded two teeth belonging to the Late Cretaceous shark Ptychodus decurrens (Ptychodontidae). The fossil record of Ptychodus decurrens from the southern continents is very poor, being known from a single Late/Middle Albian occurrence in Australia. This finding documents the first record of fossil P. decurrens in India and second from a Gondwanan landmass, and provides the first evidence of a cosmopolitan, Pangaean, distribution of the species during the Albian–Turonian and additional insights into the palaeoecology of the Cauvery Basin during the deposition of the Karai Formation.► This paper describes the Late Cretaceous shark Ptychodus decurrens (Ptychodontidae) from the Cauvery Basin, India. ► The species is found in association with an ichthyofauna comprising squaliform, hexanchiform and lamniform sharks, and ichthyosaur remains. ► Extends the geographical distribution of Ptychodus decurrens into Gondwanan landmasses. ► Paper also describes the palaeobiogeographical implication of the new find.
    Vertebrate fossils have been known from South India's Cauvery Basin since the 1840s, but records of marine vertebrates from the late Albian to Turonian Karai Formation have been limited to a single set of ichthyosaur remains. Recent... more
    Vertebrate fossils have been known from South India's Cauvery Basin since the 1840s, but records of marine vertebrates from the late Albian to Turonian Karai Formation have been limited to a single set of ichthyosaur remains. Recent surface collecting and sieving of lower Cenomanian glauconitic mudstones has yielded the first ichthyosaur material reported in India over the last 140 years, as well as a diverse and previously unrecorded shark assemblage. The ichthyosaur material, including several teeth and vertebrae, is assigned to the sole described Cretaceous genus Platypterygius and to the species P. indicus (Lydekker, 1879). Eight species of shark (one squaliformes, two hexanchiformes, and five lamniformes) are recorded. A new hexanchiform genus Gladioserratus is erected, and two new species (Gladioserratus magnus, gen. et sp. nov., and Dwardius sudindicus, sp. nov.) are named. Many of the shark genera within this largely species-level endemic fauna are known from high paleolatitudes elsewhere, with many showing an antitropical distribution, but are absent in Tethyan areas. This first description of the Karai Formation marine fauna documents the previously unappreciated diversity and unique character of India's Cretaceous marine vertebrates, and indicates a cool-water paleoenvironment for the marine vertebrate assemblage.