Early rhinocerotids (Mammalia: Perissodactyla) from South Asia and a review of the Holarctic Paleogene rhinocerotid record

Abstract

The earliest rhinocerotids from South Asia are identified on the basis of few dental remains originating from the Late Eocene of Thailand (Wai Lek mine, Krabi Basin) and the Early Oligocene of Pakistan (Paali nala C2, Bugti Hills). Once synthesized, the Holarctic Paleogene rhinocerotid record points out a westward diachronism of rhinocerotid First Appearance Data, from North America to Europe via Asia, throughout mid-Cenozoic times. The faunal similarity among mammal localities from the Late Eocene and Early Oligocene of peninsular Thailand, southern China, and Pakistan suggests the existence of a single South Asian paleoprovince during this interval and the persistence of a tropical-subtropical climate. Substantial faunal changes recorded in eastern Balochistan reveal a significant climatic deterioration from the middle part of the Oligocene. Neither provinciality nor endemism is noticeable for rhinocerotoid taxa recognized in the Oligocene of the Indian subcontinent: neither the Himalayas nor the Tibet Plateau was a paleogeographic barrier for large mammals during this interval.