Middle Miocene small mammals from the Siwalik Group of Northwestern India

Abstract

The freshwater Siwalik deposits of the Himalayan foreland basin have long been known to yield prolific Miocene-Pleistocene mammalian fauna. Overwhelming of this data comes from the Siwalik sequence of Pakistan, where good palaeomagnetic control is available for various Siwalik lithounits. In contrast limited data on fossil mammals, more so on small mammals, is available from the Indian side of the Siwalik, where even most of the Siwalik formations lack palaeomagnetic and or radiometric calibration, despite the fact that several fossil yielding localities are known in India since long. In the present research work, small mammals discovered from a Lower Siwalik locality near Ramnagar town in Jammu province, Jammu and Kashmir State, India are reported and their age implication is discussed. The mammal fauna from the study area contains four species of rodents belonging to four subfamilies. These include Rhizomyinae represented by Kanisamys indicus, Ctenodactylinae by Sayimys sivalensis, Myomiminae by Myomimus sp. and Xerinae by Tamias urialis. The recovered biotas improve our knowledge on the rodent diversity of the Indian Lower Siwalik Subgroup and contribute to further constrain the age of the fossiliferous horizon between 13.6 and 13.2 Ma. The new fauna suggests a humid, forested palaeoecological setting.