New fossil remains of Rhinocerotidae (Perissodactyla) from the early Late Miocene Tebingan area, central Myanmar

Abstract

ABSTRACT New fossil remains of Rhinocerotidae, dated from the early Late Miocene, were discovered from the lowermost part of the Irrawaddy Formation in the Tebingan area, Magway Region, central Myanmar. The Tebingan rhinoceros fossils, consisting of isolated teeth, maxillae, and mandibles, are assigned to three taxa: Brachypotherium perimense defined by a constricted protocone, a well-developed parastyle and broad upper teeth, to ‘Brachypotherium’ fatehjangense with a flat ectoloph, crochet, and the absence of tubercle at the entrance of the median valley. Other specimens were assigned to Rhinoceros sp. due to having a developed parastyle, crochet and a strong anterior cingulum and the absence of a constricted protocone and ante-crochet. The evolutionary history of Rhinocerotidae is poorly known in Southeast Asia, and few rhinoceros’ species have been identified from the Irrawaddy Formation. The newly identified Rhinoceros specimens from the early Late Miocene Tebingan area are the oldest fossil records for Rhinoceros in Southeast Asia. The Tebingan mammal fauna is similar to the Nagri and Dhok Pathan faunas of the lower/middle Siwaliks of the Indian subcontinent, indicating the faunal exchange between these two regions in the late Neogene.