Juvenile skulls and other postcranial bones of Coelodonta nihowanensis from Shanshenmiaozui, Nihewan Basin, China

Abstract

ABSTRACTShanshenmiaozui in the Nihewan Basin of China is the locality that has produced the richest sample of Coelodonta nihowanensis material, including a nearly complete juvenile skull and mandible as well as various other cranial, mandibular, and postcranial bones. All of the cranial and mandibular specimens belong to individuals around 1.5 years old. On the basis of both qualitative morphological characters and osteometric measurements, the new specimens can be provisionally referred to the species Coelodonta nihowanensis. They also fall within the range of variation seen in late Pleistocene Coelodonta antiquitatis, but are distinct from this species in having developed cingula, relatively low-crowned teeth either with or without very thin cement on the surface, vestigial lower incisors, less backward-curved protolophs, and more slender limb bones. The newly discovered juvenile skull of Coelodonta nihowanensis from Shanshenmiaozui represents the only known complete juvenile skull of an early member of Coelodonta, and therefore has great significance for understanding the development and evolution of the genus. Extensive comparisons with all other Coelodonta species, and with extant rhinoceroses, indicate that the new specimens are much more similar to the true woolly rhino Coelodonta antiquitatis than to any other taxon.SUPPLEMENTAL DATA—Supplemental materials are available for this article for free at http://www.tandfonline.com/UJVP.