This paper describes new fossils of Equus huanghoensis from an Early Pleistocene bed in Nihewan, Hebei Province, which confirms the classification of E. huanghoensis by Chinese researchers. The new fossils include a relatively complete male skull and mandible with all upper and lower dentition, a broken female skull with fragment of mandible and a broken Mc III of Equus sp. The fossils were collected from the Yangshuizhan site of Nihewan. The age of the formation is about 1.6 Ma. The new materials verify some classification characteristics based on teeth published in previous descriptions. These characteristics include large teeth size, short protocone, and tilted protoloph and metaloph. We have added to these characteristics of large skull size, a developed protuberantia supramagna, pentagonal nuchal side, weak Pli cabaline, simple enamel plications; a series of new characteristics strikingly different from the other Equus horses. The broken Mc III is similar to Equus qingyangensis from Qingyang, Gansu.
LI YongXiangZHANG YunXiangSUN BoYangAO HongXUE XiangXu
The north-trending Liupan Shan （六盘山） is an important tectonic boundary between the Tibetan Plateau and the Ordos platform. The Late Cenozoic red earth deposits of the Liupan Shan record its tectonic history and environmental effects. In this article we report a new Late Cenozoic red earth section from an intermontane basin in the southern part of the Liupan Shan. Lithofacies analysis, paleomagnetic and fission-track chronologies, and paleocurrent analysis have been employed to identi- fy the tectonic uplift events of the Liupan Shan. Based on the age constraints of mammal fossils, the pa- leomagnetic polarity zones of the Huating （华亭） Section can be approximately correlated with the standard polarity zones that lie between C3An.2n and C5n.ln of the Geomagnetic Polar- ity Timescale; the bottom age of this section is approximately 10 Ma. Based on this and the previous studies, we infer that a tectonic event commenced in the southern Liupan Shan in this interval between 8.3 and 8.7 Ma, accompanied by a remarkable increase in sediment accumulation rate. Field observations, fission-track dating, determinations of grain-size frequency distribu- tions and the vertebrate fossils found there suggest that the red earth deposits were reworked by water and mainly transported by fluvial-alluvial processes from the adjacent area.
