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根据新材料修订了Ｄｉａｎｏｍｙｓ属及其两个种（Ｄ． ｏｂｓｃｕｒａｔｕｓ和Ｄ． ｑｕｊｉｎｇｅｎｓｉｓ）的鉴定特 征。原定为Ｄ、ｏｂｓｃｕｒａｔｕｓ的Ｐ４应为ｄＰ４，原定的Ｍ１／２和ｍ１／２分别被确认为Ｍ１和ｍ２，原属 Ｄ．ｏｂｓｃｕｒａｔｕｓ的ｐ４，实属Ｄ．ｑｕｊｉｎｇｅｎｓｉｓ。Ｄ．ｑｕｊｉｎｇｅｎｓｉｓ与Ｄ．ｏｂｓｃｕｒａｔｕｓ的区别除个体较大 外，还在于其上颊齿具分叉的后脊，ｍ１具下中脊和ｐ４具较发育的附加刺。另建立了一新属 （杨氏鼠Ｙｏｕｎｇｏｍｙｓ），包括二新种（云南杨氏鼠Ｙ ．ｙｕｎｎａｎｅｎｓｉｓ、小杨氏鼠Ｙ ｐｉｓｉｎｎｕｓ）和一未 定种（Ｙｏｕｎｇｏｍｙｓ？ｓｐ．）。ｙｏｕｎｇｏｍｙｓ的主要特征为：颊齿比例上较窄长，齿冠较低，主尖钝，脊 较细而低；上臼齿长大于宽，后脊向原尖斜伸，内脊较低；下臼齿下原尖后臂较向后伸，无明显 的舌部，下内尖臂很弱，横向，不与下外脊连等。 Ｙ ｐｉｓｉｎｎｕＳ与 Ｙ ｙｕｎｎａｎｅｎｓｉｓ的区别在于个体 较小，齿冠较低，脊更细弱，较显丘形，上臼齿次尖位置向舌侧移，具较明显的后小尖，和后脊 不与原尖连等。 用ＰＡＵＰ ３．１．１对亚洲古近纪的梳齿鼠类进行了系统分析，表明第四前臼齿的
The identification of Dianomys and its two species (D. obscuratus and D. qujingensis) was revised based on the new material. Originally designated as D, obscuratus P4 should be dP4, the original M1 / 2 and m1 / 2 were identified as M1 and m2, the original D. p4 of obscuratus qujingensis. D. qujingensis and D. The distinction between obscuratus, in addition to the larger individual, lies in the bidentate posterior spine of the cheek tooth, m1 with the lower spine and p4 with more developed additional spines. A new genus (Youngomys) was also established, including two new species (Y. yunnanensis, Y pisinnus and Youngomys? Sp.). The main features of youngomys: the ratio of the cheek teeth narrower, lower crown, the main tip of the obtuse, the spine is thinner and lower; the molar longer than the width of the back, the original ridge oblique spine, lower internal ridge; lower molar tooth The back of the original sharp back than the back, no obvious tongue, under the spine is very weak, lateral, not with the lower outer spine and so on. The difference between Y pisinnuS and Y yunnanensis is that the individual is smaller, the crown is lower, the ridge is finer, the more mound shape, the inferior position of the superior molar moves to the lingual side, Tip even. A systematic analysis of ancient palaeo-rodents in Asia with PAUP 3.1.1 shows that the fourth premolar