甘肃党河下游地区早渐新世哺乳动物化石的发现

描述了产于党河下游地区的狍牛泉组下部地层中的叮当沟哺乳动物群。化石共计 1 1属 1 4种 :Palaeoscaptorcf.P .acridens、Palaeoscaptorsp .、Oligosciurusdangheensisgen .etsp .nov.、Tataromyscf.T .sigmodon、Karakoromysdecessus、Coelodontomysasiaticus、Parasminthusspp .、Cricetidaegen .etsp .indet.、Desmatolagusgobiensis、D .pusillus、Allaceropssp .、Schizotheriumordo sium和Parabrachyodussp .。党河鲜松鼠 (新属、新种 )的主要特征是个体较小而原始 ,下颌骨咬肌窝前缘达m2下方 ;冠状突前缘近于垂直 ,起于m2后部下方 ,颊齿齿冠很低 ,臼齿具明显的下内尖、下次脊和下中附尖 ,但无下中尖。上述化石的已知时代分布表明 ,狍牛泉组下部的叮当沟哺乳动物群的时代为早渐新世

DISCOVERY OF EARLY OLIGOCENE MAMMALIAN FOSSILS FROM DANGHE AREA,GANSU,CHINA

The lower reach of the Danghe River = Taben buluk area of Bohlin (1942)] is one of the classic areas of late Oligocene in the Asian Paleogene biostratigraphy (Bohlin, 1942, 1946). In 1999 and 2001 a joint team of Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences (IVPP), Institute of Cultural Relics and Archaeology, Gansu, and Provincial Museum of Gansu made a geologic survey of the Danghe area. During the survey some new mammalian fossils of early Oligocene were found. The new find indicates that the Danghe Basin received its Cenozoic deposits from early Oligocene rather than late Oligocene as previously thought. All of the specimens described here are collected from the lower part of the Paoniuquan Formation in the Tiejianggou valley, Aksay Kazak Autonomous County, Gansu Province.