A Pleistocene rhinocerotid (Mammalia, Perissodactyla) from the Bisan-Seto area, western Japan

Abstract

We describe the characteristics of a Rhinocerotidae femur and tibia found within sea-floor sediments in the Bisan-Seto region, western Japan, a region for which the mammal fauna has been assigned the Middle Pleistocene age. Based on morphological and metrical comparisons between the studied specimens and those from Pleistocene rhinoceroses from Eurasia (Stephanorhinus, Coelodonta, and Rhinoceros), the studied specimens can be referred to as Stephanorhinus sp., although their more specific identification is not possible given a lack of further skeletal elements. Nevertheless, our study confirms the presence of Stephanorhinus during the Middle Pleistocene in Japan and supports similar finds elsewhere in western Japan (e.g., Isa in Yamaguchi Prefecture).