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

Abstract

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.