Abstract: "Pliopentalagus nihewanensis" was described by Cai (1989) , based on an isolated p3 and two isolated lower molariform teeth from the bottom of the " Nihewan beds" of Hebei Province, China. Detailed re-examination of the original specimens and comparisons with other species of the genus and Trischizolagus suggest: 1 ) the holotype (p3) alone can be interpreted as a species of the genus Pliopentalagus having p3 with least complicated enamel pattern. But, this hypothesis violates an evolutionary trend of the genus that the enamel pattern becomes more complicated through time. On the other hands, 2) the holotype can also be interpreted as a species of the genus Trischizolagus having p3 with most complicated enamel pattern. This hypothesis fits on an evolutionary trend of the genus that enamel pattern becomes more complicated through time ( Averianov and Tesakov , 1997 ) 3) the associated fauna which is indicative of a dry and cool environment also suggests that the holotype may not belong to the genus Pliopentalagus. Therefore, we conclude that generic assignment of this taxon should be Trischizolagus, and T. nihewanensis is characterized by p3 with most complicated enamel pattern within the genus.

摘要： 自20世纪60年代，欧亚大陆晚新生代地层中陆续发现了p3由5个主要褶沟组成的兔类化石，并先后建立了上新五褶兔(Pliopentalagus Gureev et Konkova，1964)和三裂齿兔(Trischizolagus Radulesco et Samson，1967)两属。 近年，在中国安徽淮南大居山新生代晚期不同时代的洞穴、裂隙堆积物中发现了保存相当完整，数量颇多的上新五褶兔的材料。笔者在研究大居山新洞早上新世的上新五褶兔时，将其与欧亚大陆该属内的已知种和三裂齿兔的各种进行了详细比较，发现产自