Fossil tapirids are representative members of the Quaternary megafauna in southern China. Previous studies have reviewed the evolution of Quaternary tapirids in China and proposed two evolutionary lineages: the Tapirus peii-Tapirus sinensis-Megatapirus augustus lineage, and the Tapirus sanyuanensis-Tapirus indicus lineage. Among Chinese tapirids, Tapirus sanyuanensis is the closest to modern species of Tapirus. Consequently, this taxon has attracted considerable attention from researchers studying the evolution of tapirids in China and East Asia. The present study describes newly discovered fossil specimens of tapirs from the early Early Pleistocene site at the Renzidong Cave, Fanchang, Anhui Province. Most of the specimens belong to juvenile individuals, including a juvenile maxillary with DP3–4, a juvenile mandible with dp2–4, two fragments of maxillary with DP1s, a fragment of maxillary with DP3, a broken DP4, and an M1. The sizes of these specimens are medium to large, consistent with the body size of Pleistocene Tapirus in China. The well-developed metalophid of the lower premolar and the mesostyle of the upper cheek tooth are consistent with the diagnostic characters of Tapirussanyuanensis previously discovered from Renzidong Cave and the Wushan Longgupo Site in Chongqing, southwest China. Moreover, the broad medisinus of the upper cheek tooth is a typical feature of the Renzidong form. The metalophid of the lower cheek teeth of the new specimens is weaker than that of the Wushan material. These consistent morphological traits indicate that Tapirussanyuanensis from Renzidong represents a local population. The new specimens include a juvenile mandible and an M1. The mandible shows a markedly shorter snout than that of an adult. The M1 displays well-developed crista and crochet. Therefore, the new specimens not only expand the fossil record of the Renzidong tapir but also provide significant information on its ontogeny.
SUN et al. (2026) studied this question.