A new rhinocerotoids (Mammalia, Perissodactyla) from the Late Oligocene of Linxia Basin, China

ABSTRACT

The Jiaozigou Formation, the lowest fossiliferous stratum in the Linxia Basin, produces the most abundant mammalian fossils in East Asia. Although the Jiaozigou Fauna is renowned for the ‘giant rhino’ (Paraceratheriidae), evidence of relatively small rhinocerotoids is scant, consisting only of fragments. The newly identified species, Megacanodon dongxiangense gen. et sp. nov. is characterised by its small-sized body, the presence of a large canine, nearly completely molarised upper premolars, retracted nasal notch, and not-elevated occipital part. It remains unclear whether the new genus is phylogenetically close to Hyracodontidae, Eggysodontidae, or Rhinocerotidae. We tentatively designate it as a basal genus within Rhinocerotoidea, with the uncertain family affiliation.

KEYWORDS:

• Rhinocerotoidea
• Oligocene
• Linxia basin
• giant rhino fauna

Acknowledgments

We thank Wang Shiqi, Bai Bing, Gao Wei, Chen Jin, Si Hongwei, Liu Yonghong, Zhang Xuelin, and Zan Hailong (Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing, China), for their help to this work. We are grateful to Xu Yong and Chen Yu for preparing the drawing.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/08912963.2024.2357606.

Author contributions

All authors contributed to study conception and design, data collection, interpretation of results, constructing figures, drafting the manuscript and editing the manuscript. All authors reviewed the results and approved the final version of the manuscript.

Additional information

Funding

The work was supported by the National Natural Science Foundation of China [42172001], the Second Comprehensive Scientific Expedition on the Tibetan Plateau [2019QZKK0705], and the National Key Research and Development Program of China [2023YFF0804501].