The Shishugou Fauna of the Middle‐Late Jurassic Transition Period in the Junggar Basin of Western China

Abstract

The Middle-Late Jurassic transition period is a critical period for the evolution of terrestrial vertebrates, but the global fossil record from this time is relatively poor. The Shishugou Fauna of this period has recently produced significant fossil remains of dinosaurs and other vertebrate groups, some representing the earliest known members of several dinosaurian groups and other vertebrate groups and some representing the best-known specimens of their group. These discoveries are significant for our understanding of the origin and evolution of several vertebrate lineages. Radiometric dating indicates that the fauna is aged approximately 159-164 Ma. Comparisons with other similarly-aged terrestrial faunas such as Shaximiao and Yanliao show both taxonomic similarities and differences between these faunas and indicate that the Junggar deposits might have preserved the most complete vertebrate fossil record for a Middle-Late Jurassic Laurasian terrestrial fauna.

A fluvial‐aeolian system in response to aridification during the Late Mesozoic, Junggar Basin, Central Asia

“…In the early stage, lacustrine and fan deltaic sediments prevailed in the southern basin (Figure 13d). Fan delta deposits occur in the northwestern basin, while deltaic and aeolian dune deposits are present in the eastern basin (Figure 13d; Eberth et al., 2001; Vincent & Allen, 2001; Xu et al., 2022). In the late stage, the lakes expanded, and lacustrine and deltaic environments dominated the whole Junggar Basin (Figure 13e; Du et al., 2019; Li et al., 2017; Liu et al., 2022; Xing et al., 2013).…”

“…From the late Middle Jurassic, the palaeoclimate changed to seasonally arid as indicated by the occurrence of gypsum and the obvious increase in the spore genus Classopollis (Ashraf et al., 2010; Deng et al., 2015; Fang et al., 2016; Jolivet et al., 2017; Morin et al., 2018). However, the Late Jurassic Junggar Basin was not a desert with limited vegetation, as suggested by large fossil trees preserved in the eastern Junggar Basin (Hinz et al., 2010; McKnight et al., 1990) and many dinosaur fossils preserved in the Shishugou Group of the Huoshaoshan section in the East Junggar Basin (Figure 1b) and Qigu Formation in the southern Junggar Basin (Dong, 1993; Maisch & Matzke, 2019; Wings et al., 2015; Xu et al., 2022). The Late Jurassic Kalazha Formation represented the driest period with the development of large aeolian dunes (Jolivet et al., 2017).…”

“…Aridification took place during the Late Jurassic in Central and East Asia (Yi et al, 2019), resulting in dramatic climate change and widespread aeolian deposits (Fang et al, 2016;Jolivet, 2017;Morin et al, 2018;Xu et al, 2013Xu et al, , 2016Xu et al, , 2019. The northernmost aeolian deposits associated with that event have been described in the intracontinental Junggar Basin, in Central Asia (Eberth et al, 2001;Fang et al, 2016;Jolivet et al, 2017;Vincent & Allen, 2001;Xu et al, 2022; Figure 1a). Fang et al (2016) suggested that aeolian deposits occur in the Oxfordian-Kimmeridgian Qigu Formation, and Jolivet et al (2017) reported erg deposits during the deposition of the Tithonian Kalazha Formation in the southern Junggar Basin.…”

“…Fang et al (2016) suggested that aeolian deposits occur in the Oxfordian-Kimmeridgian Qigu Formation, and Jolivet et al (2017) reported erg deposits during the deposition of the Tithonian Kalazha Formation in the southern Junggar Basin. Aeolian deposits were also reported from the eastern Junggar Basin in the Early Cretaceous (Eberth et al, 2001;Vincent & Allen, 2001;Xu et al, 2022;Figure 1b) and the Turpan-Hami Basin (Shen et al, 2020;Figure 1b), which is assumed to be connected with the Junggar Basin during the Early Jurassic (Fang et al, 2019). Although Jolivet et al (2017) regarded the thick grey sandstones of the Kalazha Formation as aeolian deposits, some researchers proposed different sedimentary environments, including delta front, lakeshore, and braided river delta (Gao et al, 2022;Guan et al, 2020;Schneider et al, 1992;Si et al, 2021).…”

Salt‐Lake Basin Bedrock Weathered Crust Gas Reservoir in the Altun Mountains Front of the Qaidam Basin, Western China

“…10). The strike-slip stress state of cracks in different motion types of the Altun footings is dominant, as can be seen from the general occurrence of reverse-fracture fractures associated with sutures (Kulander et al, 1990;Ameen and Hailwood, 2008;Xu et al, 2022).…”