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记述了甘肃肃南县鲁沟上二叠统肃南组的二齿兽一新种──Ｄｉｃｙｎｏｄｏｎ ｓｕｎａｎｅｎｓｉｓ ｓｐ． ｎｏｖ．。它以额骨与前颌骨相连，在接触处具一深的凹坑，和向前延伸的位于前颌骨中线上的一浅沟；左右鼻骨不在中线相遇。泪骨向前延伸超过前额骨等特征区别于Ｄｉｃｙｎｏｄｏｎ的其他种。它与新疆锅底坑组的Ｄｉｃｙｎｏｄｏｎ ｂｏｇｄａｅｎｓｉｓ关系密切。祁连山地区二叠系、三叠系的研究对比表明：１）肃南组的命名剖面──大青沟剖面只包括肃南组下部，该组由上下两部分组成，这在羊露河剖面和鲁沟剖面中可以得到证实。２）过去广泛使用的西大沟组（群）或“中下三叠统”，其地质体是指整合于窑沟组杂色岩之上，和产晚二叠世安加拉与华夏型混生植物群的肃南组之下的一套紫红色粗碎屑岩层。３）鲁沟剖面中覆于肃南组之上，和伏于下、中侏罗统含煤岩系之下的砂岩夹砾岩及细砂岩层，被命名为鲁沟组，属下三叠统。
A new species of dichotoma, Dicynodon sunanensis sp., From the Permian Sunan Formation in Lugou, Sunan County, Gansu Province, is described. nov . It is connected to the frontal bone forehead with a deep dent in the contact, and the forward extension of the midline of the premaxilla on a shallow ditch; left and right nasal bone does not meet in the midline. Tearles extend forward beyond the forehead bone and other characteristics different from other species of Dicynodon. It is closely related to Dicynodon bogdaensis in the pot bottom pit group in Xinjiang. Comparison of Permian and Triassic in the Qilian Mountains shows that: 1) The named section of Sunan Formation - the Daqinggou section only includes the lower part of Sunan Formation, which consists of upper and lower sections, Lugou profile can be confirmed. 2) The Xidagou Formation (Group) or “Middle-Lower Triassic”, which was widely used in the past, is characterized by the integration of the geological body on the mottled karst rock in the Yaogou Formation and the mixed occurrence of Angara and Huaxia type in the Late Permian A set of purplish-red coarse-grained rock formations beneath the Sunan Formation of the flora. 3) The Lugou section is overlain by the Sunan Formation and sandstone and conglomerate and sandstone formations beneath the Middle and Jurassic coal-bearing rocks are named Lugou Formation and under the Triassic System.