Palaeogeography, Palaeoclimatology , Palaeoecology, 31(1980): 39--62 39 © Elsevier Scientific Publishing Company, Amsterdam -- Printed in The Netherlands NEOGENE PALAEOBIOGEOGRAPHY OF THE INDIAN SUBCONTINENT WITH SPECIAL REFERENCE TO FOSSIL VERTEBRATES ASHOK SAHNI 1 and HARISH CHANDRA MITRA Geology Department, Lucknow University, Lucknow 226007 (India) (Received April 19, 1979; revised version accepted January 22, 1980) ABSTRACT Sahni, A. and Mitra, H.C., 1980. Neogene palaeobiogeographyof the Indian subcontinent with special reference to fossilvertebrates. Palaeogeogr., Palaeoc]imato].,Palaeoecol., 31: 39--62. The geologicalhistory of the Indian subcontinent during the Neogeneshows firstly, a progressive continentality in sedimentation ; secondly,variable climatic trends ranging from warm, tropical rain-forestconditions throughout the Mioceneup to the Early Plio- cene, with a drier climate in the P]iocene, graduallychangingto glacialconditions by the Middle Pleistocene;thirdly, a southerly and easterly shifting of climatic zones; and lastly, a remarkable stability in marine and non-marinesedimentaryregimes, with the Himalayas representing the main source of sediments for north India from the Mioceneonwards. This stability is also evidencedby marine and non-marinefaunas. Thirty to forty percent of the species of the Miocenemarine molluscsand elasmobranchs are common to Recent taxa in the Arabian Sea and Bay of Bengal.Pliocene Siwalikfishes are referable to present-day forms in the Indo-Gangetic Plain rivers with the exception of Heterobranchus which is presently restricted to Africa. In contrast to the Palaeogene,coal occurs less frequently in the Neogene. The Neogene also shows a widespread distribution of mammalianfaunas, which con- stitute the main criteria for stratigraphic correlation of non-marinedeposits. The occur- rence of certain Mioceneand Pleistoceneplain-dwelling mammalsin areas which today are highly elevated (Kashmir)testifies to Neogene impulsesof the Himalayanorogeny. Early Neogene (Lower Miocene) mammalsfrom the Indian subcontinent show an inter- mixture between southern Russianand African forms. INTRODUCTION This paper is a sequel to an earlier study which dealt with the Palaeogene palaeobiogeography of the Indian subcontinent (Sahni and Kumar, 1974). In view of the rather varied and new data that have been obtained as a result of studies connected with a plate-tectonics model of the subcontinent, it becomes necessary to evaluate data concerned with marine zoogeographic and terrestrial phytogeographic provenances during the Late Tertiary. Other parameters such as a chronological documentation of transgressions and re- gressions mark important stratigraphic datum lines and also give the relative I Present address: Centre of Advanced Study in Geology, Punjab University, Chandigarh 160014 (India).