Cretaceous insular India - Consequences for biological evolution and faunal interchanges

India underwent a significant length of northward journey after its break-up from the contiguous landmasses of Gondwana and remained for a large part of the time, particularly during the Cretaceous Period, physically isolated from other landmasses.The consequences of a long period of isolation for constituent biological communities are evaluated in this review by examining the Late Cretaceous fossil biota of India.The fossil record from the Upper Cretaceous Lameta Formation, Deccan intertrappean beds, and the Kallamedu Formation bring forth fauna and flora that are considered to have taxonomic affinities either to those of Gondwana or Laurasia or had origins in the northward drifting Indian plate.During the present analysis, it is inferred that the fauna of Gondwana affinity confirms a vicariant biogeographic scenario with many of the taxa having sister group relationships with those of Madagascar.Several taxa, such as adapisoriculid mammals, bothremydid turtles, ostracods, and at least five plant groups were endemic to India and made their way to Laurasia following India/ Asia collision thus supporting out of India dispersal hypothesis.The taxa of Laurasian lineages are interpreted to have dispersed into India using Kohistan-Dras-Oman island arcs as steppingstones, facilitated by a sweepstakes mode of dispersal.