# New materials of plesiacerathere (Perissodactyla, Rhinocerotidae) from the late Early Miocene of Northern China

## TL;DR

New fossils of Plesiaceratherium from China reveal a new species, P. tongxinense, expanding our understanding of rhinoceros evolution in the Miocene.

## Contribution

The discovery and description of a new Plesiaceratherium species from Northern China, with detailed morphological and phylogenetic analysis.

## Key findings

- Plesiaceratherium tongxinense is a new species identified from well-preserved fossils in Northern China.
- The species exhibits unique dental and cranial features distinguishing it from other Plesiaceratherium species.
- Phylogenetic analysis places P. tongxinense in a basal position within the genus.

## Abstract

As a member of Aceratheriinae, the genus Plesiaceratherium in Europe is widely distributed and highly diverse. However, only one species of Plesiaceratherium (i.e., P. gracile) exists in China with a discontinuous distribution range. Recently, we have discovered new materials of Plesiaceratherium in the lower layers of the Zhang’enbao Formation exposed in Miaoerling in Tongxin County, China. The new materials are well-preserved and can be separated from other Plesiaceratherium species by the following combination of features: the long and generally flat skull, with closed frontoparietal crests; the deep nasal notch at the level of P4; the high supraorbital margin, with its anterior margin at the level of the M1/M2 boundary; the medium-sized upper I1, with an oval abraded surface; the semi-molarized upper premolars with the protocone and hypocone joined by a lingual bridge; the strong constrictions of protocone on the upper molars; the absent buccal cingulum on upper cheek teeth; the cheek teeth are covered by cement on the buccal walls; the convex base of mandibular corpus; the inclined backward ramus; and the mandibular foramen above the teeth neck. Based on the combination of characteristics and phylogenetic analysis, we herein establish the new species as Plesiaceratherium tongxinense sp. nov. living in the late Early Miocene. Phylogenetic analysis reveals that P. tongxinense is in the basal position of the genus Plesiaceratherium, providing more detailed morphological characteristics of the plesiaceratheres.