Discovery of a primitive Gomphotherium from the Early Miocene of northern China and its biochronology and palaeobiogeography significance

ABSTRACT

Gomphotheres are age-informative mammals that had widespread distribution during the Neogene. In this paper, we report new fossil Gomphotherium remains from the Early Miocene of Tongxin County, North China. The new material is similar to Gomphotherium cooperi in cheek tooth morphology and can be assigned to the same species. Gomphotherium cooperi, was previously reported only from Dera Bugti, the Early Miocene of South Asia. According to the research of relevant stratigraphic correlation and biostratigraphy, we estimated the age of the lower layer of the Zhangenbao Formation, where the new fossil was recovered, is approximately between 18 and 19 Ma. The occurrence of a similar Early Miocene proboscidean assemblage in both China and South Asia is further evidence that mammal dispersal between the two regions may have existed at that time. It also suggests that the Tibetan plateau was not high enough to block exchange among large animals like proboscideans. This work reveals the distribution and dispersal of Gomphotherium between South Asia and China through the Tibetan region during the Early Miocene and provides important biochronology and palaeobiogeography significance.

KEYWORDS:

• Gomphotherium
• Early Miocene
• North China
• dispersal
• biochronology

Acknowledgments

We thank Jie Ye for his great guidance and suggestions on stratigraphy. We thank Licheng Guo at the Institute of Geology and Geophysics, Chinese Academy of Sciences for his help and suggestions on the last figure. We are grateful to the reviewers and editor for providing constructive advice and suggestions.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (XDA20070203, XDB26000000, XDA20070301), the Second Comprehensive Scientific Expedition on the Tibetan Plateau (2019QZKK0705), Natural science foundation of Ningxia, the Genesis of Geological Relics and Ecological Protection in the Yellow River Basin of Ningxia (2020AAC03462), and the Special Research Program of Basic Science and Technology of the Ministry of Science and Technology (-DD20190009)