Several tritylodontid taxa have been reported from the Upper Jurassic of the Wucaiwan area in the Junggar Basin of Xinjiang, northwestern China, including Yuanotherium minor. The original study described the partially preserved postcanine teeth in the middle of the left upper maxilla. After detailed re-examination of the specimen and by CT scanning, 3D reconstruction, and scanning electron microscopy observations, we provided a more detailed description of the osteology, neurosensory, and tooth wear pattern for all the bones preserved in this specimen and clarified some characters. Based on new information about the cusp wear pattern, the chewing movement pattern of the dentition and detailed cusp morphology, we discussed the cuspal homology of upper cheek teeth of tritylodontids and postulate a standardized method for cusp identification. We hypothesize that the unique maxilla characteristics furnish the evidence for transitional stages about the evolution of the upper jaw-palate structure in tritylodontids.

The micromammal fossils collected from the Shangzhuang Formation of the Linxia Basin, Gansu, are described here. The assemblage consists of 16 species of 13 genera belonging to 7 families, including one new species and one taxon previously unknown from China. Among them 5 genera are Oligocene holdovers and 11 genera/species are known to make their first appearances in Early Miocene, indicating an Early Miocene age for the Gucheng Fauna. The absence of Oligocene survivors such as Tataromys, Yindirtemys, Eucricetodon and Tachyoryctoides, which usually occur in the Xiejian age of Early Miocene, and the presence of newcomers Protalactaga, Megacricetodon and Gobicricetodon, that made their first appearance only in the Shanwangian age of late Early Miocene, suggest that the Gucheng Fauna is of a later age of Early Miocene. The new species, Sinolagomys guchengensis, showing more derived morphology than in S. ulunguensis, seems to support an assessment of the fauna in Shanwangian age. Thus, the Gucheng Fauna may belong to late Early Miocene Shanwangian, partially equivalent to MN 3/4 of the European land mammal zonation. Ecological analysis of the fauna indicates that the palaeoecological condition of the Gucheng area might still be a predominantly arid shrub-steppe in late Early Miocene.

Monsoon has an important impact on the development of vegetation that subsequently has significant influence on the evolution of plant consumers. The diversities of forest dwellers or herbivores follow the evolution of the vegetation, and it is therefore possible to take such diversities as forest or vegetation dynamic proxies. The present work selected 36 Pleistocene faunas of large mammals from monsoon-dominated provinces in China as materials and calculated the diversities of forest dwellers and herbivores with different approaches, as well as the consensus gradient coefficients of all the selected faunas in different flora regionalized subkingdoms. The results show that with the evolution and transitions of the East Asian summer and winter monsoon intensities, the forest vitality decreased while steppe vitality increased gradually in a fluctuated way from the Early Pleistocene to the Late Pleistocene, especially in the provinces north of the Qinling-Huaihe Line. The analyses of such diversities of the faunas can help to determine the forest dynamic proxies. Moreover, the correlation of such proxies to loess-paleosol sequences and marine isotope stages can in turn help to improve the accuracy of dating fauna ages and paleoenvironment reconstruction.

The Upper Cretaceous of Tantou Basin in western Henan has yielded many vertebrate fossils, which are featured by several non-avian dinosaurs. Meanwhile, studies on their eggs were yet inadequate though many eggshells have been reported. The newly discovered material 41HⅤ0199 was excavated from the Upper Cretaceous Qiupa Formation in 2021. The block preserves eight complete eggs arranged in two partial rings that form a partial clutch, and there are some scattered eggshells preserved closely with the block, showing a concave-up to concave-down ratio of 54.5 : 45.5, which indicates that the scattered eggshells come from the clutch and the clutch had been partially broken before it was buried. Based on morphological and microstructural characteristics, the eggs and eggshells can be assigned to Macroolithus yaotunensis (Elongatoolithidae), an oospecies known to be related to oviraptorids, which leads Yulong mini to be its probable producer. Besides, some eggshells show microstructural signs indicating egg retention, which marks the second example of egg retention in the oofamily Elongatoolithidae.