Himalayan Geology, Vol. 21 (1& 2), 2000, pp. 39-42, Printed in India

The Great Small Mammal Revolution

LAWRENCE J. FLYNN
Peabody Museum, Harvard University, Cambridge, Massachusetts 02138, USA

The small mammal fauna of the Indian Subcontinent underwent turnover of massive scale in early Miocene time. The archaic ctenodactyloid rodent assemblage known from Bugti, Sulaiman, and Ladakh deposits of early Miocene age was replaced in no more than two million years by a completely different fauna, different at the family and higher taxonomic levels. This scale of turnover is unheard of anywhere, at any time in earth history, except in the most catastrophic situations. Other small mammal groups participated in the turnover;the scale of change for large mammals is unstudied so far. Apparent diversity before and after the turnover is comparable. One lineage survived the event, although in reduced abundance as measured by fossils. This is the Fallomus-Diatomys clade of non-baluchimyine ctenodactyloids. This lineage endured the demise of the Bugti small mammal fauna, survived into early late Miocene time, and appeared sporadically in the Siwalik Group of rocks and elsewhere in Asia.