摘要: Currently, there are still different views regarding the chronology of the Late Cenozoic
deposits in the Nihewan Basin, which results from the contradiction between biostratigraphic
correlations based on mammalian fossils and magnetostratigraphic dating results. Biostratigraphic
correlations indicate that the aeolian red clay exposed in the Sanggan River canyon, the fluviolacustrine
red clay with sands and gravels, and the sandy clay of swamp facies on both sides of the
lower reaches of the Huliu River belong to the Upper Pliocene, whereas the magnetostratigraphic
dating usually correlates them to the Lower Pleistocene. In October 2011, a collection of
mammalian fossils was unearthed from a block of collapsed deposits at Yegou in the Nihewan
Basin, which is about 300 m north of the Laowogou section that is well known for the Pliocene
mammalian fossils from its lower part. The Yegou fossils are identified herein as 10 species in
9 genera: Nyctereutes tingi, N. sinensis, Pachycrocuta pyrenaica, Homotherium sp., Hipparion
(Plesiohipparion) houfenense, Dicerorhinus sp., Muntiacus sp., Axis shansius, Gazella blacki, and
Paracamelus sp. The fauna is quite different from the classic Early Pleistocene Nihewan Fauna in
composition and provides new evidence for the existence of the Upper Pliocene in the Nihewan
Basin. Based on a systematic description of the fauna, its composition and geological age are
discussed, and the compositional features of large mammals of the Late Pliocene and the Early
Pleistocene mammalian faunas in the Nihewan Basin are summarized.