Siwalik Mammalian Faunas from Ramnagar (J. & K.) and Nurpur (H.P.) and Lower Limit of Hipparion

Abstract Recent collections of mammalian fossils from the Siwalik sediments of Ramnagar (J.& K.) and Nurpur (Kangra, H. P.) indicate the presence of Chinji Fauna in the red bed sequence exposed in the vicinity of Ramnagar, but in Nurpur despite the dominance of the red clays which are usually considered as characteristic for the Lower Siwalik Subgroup, the fauna indicates an age equivalent to the Middle Siwalik. The mammalian fossils collected by the earlier workers are reinterpreted and the fossils, which include Propotamochoerus hysudricus. Merycopolamus dissimilis and Bramatherium megacephalumminus, are found to be indicative of Middle Siwalik age rather than the Lower Siwalik or the Lower-Middle Siwalik transitional age as was considered earlier. Hipparion (includes Hipparion and Cormohipparion) has been recorded by all the workers in Nurpur and now its arrival in India is considered at about 10m.y. The 12.5 m.y. dispersal event of hipparion in the Old World is found missing in the Siwalik Group. Though hipparion has been recorded from the so-called Lower Siwalik sequence of Kalagarh, U. P. but so far it is not recorded from the type section of Chinji in Potwar and in Dang Valley, Nepal. In the present collection, the presence of hipparion along with Dicoryphochocrus vinayaki, Hydaspifherium megacephalum, etc. from Nurpur is indicative of the Middle Siwalik age for the Nurpur Local Fauna. It is inferred that the red clays considered characterisitic of the Lower Siwalik are time transgressive and even the fauna colIected by earlier workers from Haritalyangar (Himachal) and Kalagarh (U.P.) is (at least a part of it) of Middle Siwalik age. Ramnagar Fauna, recently collected by the authors, is true Chinji Fauna and is characterised by the presence of Dicoryphochoerus haydeni, Conohyus chinjiensis, Anthracotherium punjabiense, Dorcabune anthracotherioides, Hemimeryx pusillus, Giraffa priscilla etc. In Ramnagar area the Lower Siwalik Subgroup and the underlying Murree Formation have a conformable contact and fauna collected at the base of the Lower Siwalik Subgroup is found to be of Chinji age. So there are all possibilities that upper part of the Murree Formation may be of Kamlial age (i.e., lower part of the Lower Siwalik).