CTENODACTYLOID RODENT ASSEMBLAGE FROM KARGIL FORMATION, LADAKH-MOLASSE GROUP - AGE AND PALEOBIOGEOGRAPHIC IMPLICATIONS FOR THE INDIAN SUBCONTINENT IN THE OLIGOMIOCENE
Ac. Nanda et A. Sahni, CTENODACTYLOID RODENT ASSEMBLAGE FROM KARGIL FORMATION, LADAKH-MOLASSE GROUP - AGE AND PALEOBIOGEOGRAPHIC IMPLICATIONS FOR THE INDIAN SUBCONTINENT IN THE OLIGOMIOCENE, Geobios, 31(4), 1998, pp. 533-544
Two ctenodactyloid rodents, Fallomus razae FLYNN, JACOBS & CHEEMA and
F. ladakhensis nov. sp., are being described from the Kargil Formation
of the Ladakh Molasse Group of Kargil area. Fallomus (? Chapattimyida
e) is considered an endemic offshoot of the South Asian Eocene ctenoda
ctyloid stock. The new species is relatively larger and more hypsodont
with an ectostylid borne on a separate pillar. At Kargil, Iberomeryx
(= Cryptomeryx) savagei and Lophiomeryx kargilensis were earlier repor
ted and indicate an Upper Oligocene age for the lower part of the Lada
kh Molasse Group. Both these taxa show Eurasian affinity. From the upp
er part of the Ladakh Molasse Group i.e. Pashkyum Formation, Hyoboops
palaeindicus is known and indicates a Lower Miocene age for the lower
part of the Pashkyum Formation. The fossil vertebrates suggest an age
for the Ladakh Molasse Group extending from Upper Oligocene to Middle
Miocene. The incisor enamel ultrastructure of Fallomus is multi-serial
with average inclination of the Hunter Schreger Bands varying between
30 degrees-35 degrees.