| 论文摘要 |
The East Asian records of Amphicyon are rare, fragmented, and unclear. Heretofore, no material could be definitely assigned to this genus. Here, we report a maxillary fragment with P4–M2 and the M3 alveolus from the early middle Miocene Dingjia’ergou fauna, Tongxin, northern China. The enlarged and anteroposteriorly elongated M2 clearly allows us to assign the specimen to Amphicyon as Amphicyon zhanxiangi, sp. nov. The new species is closest to European A. giganteus (e.g., presence of the parastyle and a posteriorly located protocone of P4) and represents an immigrant from Europe during the late early or the earliest middle Miocene. The morphological differences between Amphicyon zhanxiangi, Amphicyon ulungurensis, and North American Amphicyon species suggest at least three dispersal events of the genus from Europe to East Asia during the early and middle Miocene. Amphicyon sp. from the late Miocene site in the Lower Irrawaddy near Magway, Myanmar, shares the enlarged and anteroposteriorly elongated M2 with Amphicyon zhanxiangi and could be a descendant of the latter species. |
