Eurasiatic elements in the upper cretaceous nonmarine biotas of penisular India

Abstract

The Upper Cretaceous terrestrial biotas of the Indian peninsula provide a good example of the presence of several taxa recorded previously in the Late Cretaceous-early Palaeocene sequences of Laurasia, particularly Central Asia and Europe. Such occurrences are noted in diverse groups including vertebrates (mammals, crocodiles, frogs), invertebrates (ostracodes) and plant remains (charophytes, palynomorphs). Of particular significance is the existence of small-sized palaeoryctid mammals which are closely allied to forms known from mid-western North America and Central Asia. Pelobatid frogs and alligatorine crocodiles provide additional supportive evidence. Similarly, the Eurasiatic affinity is also reflected by ostracodes and charophytes, many of which are generically identical to forms known from Mongolia and China (e.g. the charophyte genus Nemegtichara and the ostracodes Altanicypris and Talicypridea. These examples along with other taxa demonstrate the cosmopolitan nature of the Indian Cretaceous nonmarine biotas and necessitate rethinking of current geodynamic models for dispersal involving island arcsmicroplates; an Indian plate not far removed from its present position; and a Terminal Cretaceous collision.