分类: 生物学 >> 动物学 提交时间: 2017-11-07 合作期刊: 《古脊椎动物学报》
摘要: Numerous assemblages of fossil small mammals have been recovered from the Neogene deposits in China over the last 30 years or so. Nevertheless, some taxa in these faunas are represented by only a small number of isolated teeth from very few localities, and these are often assigned as indeterminate genus or species. Four peculiar taxa of rodents, Sayimys sihongensis, Apeomys asiaticus, Neocometes sp. from the Early Miocene Xiacaowan Formation of Sihong, Jiangsu Province, and Yuneomys pusillus from the Late Miocene Shihuiba Formation of Lufeng, Yunnan Province, are described in detail. Comparison of these specimens with similar materials from Eurasia or North America makes distinction from the known species of related genera possible, and therefore two new species (S. sihongensis, A. asiaticus) are named for the Sihong specimens, although the material is rare. A new eomyid genus Yuneomys, previously published under the name Leptodontomys pusillus, is based on specimens from Lufeng. A. asiaticus and Neocometes sp. represent the first records of the genera Apeomys and Neocometes known from Asia and China, respectively. The occurrence of the Neogene rodents in eastern China improves our knowledge of the spatial distribution of these poorly recorded animals, and contributes to a better understanding of paleobiogeographic relationships in Eurasia. Co-occurrence of the new genus with the bunodont eomyids Plesieomys and Heteroeomys in the Lufeng Fauna seems to indicate a differentiation of eomyid taxa in northern and southern faunas of China, and may reflect ecological partitioning within southeastern Asia during the Miocene.