- Source: Yangliujing Formation
The Yangliujing Formation is a Middle Triassic geologic unit found in the Guizhou and Yunnan Provinces of southern China.
Description
Most of the formation is represented by massive dolomites, indicative of a shallow-water depositional environment. Fossils are generally rare, but conodonts from the Anisian-Ladinian boundary (namely several species of Neogondolella) are known from the lower part of the formation. Some marine reptiles have been found in dolomitic limestone near Dingxiao, an area of Guizhou sometimes considered to preserve the upper part of the Yangliujing Formation. However, under a more restrictive definition of the Yangliujing Formation, the fossils of Dingxiao would instead belong to the overlying Zhuganpo Formation.
Fossil content
The following fossils have been reported from the formation:
Fish
Omanoselache contrarius
?Parvodus sp.
?Semionotiformes indet.
Brachiopods
Mentzelia sp.
Nudispiriferina sp.
Bivalves
Asoella illyrica
Unionites sp.
Crinoids
Traumatocrinus hsui
Conodonts
Ozarkodina kockeli
References
= Bibliography
=Sun, Zuoyu; Jiang, Dayong; Ji, Cheng; Hao, Weicheng (2016), "Integrated biochronology for Triassic marine vertebrate faunas of Guizhou Province, South China", Journal of Asian Earth Sciences, 118: 101–110, Bibcode:2016JAESc.118..101S, doi:10.1016/j.jseaes.2016.01.004, ISSN 1367-9120
Benton, Michael J.; Zhang, Qiyue; Hu, Shixue; Chen, Zhong-Qiang; Wen, Wen; Liu, Jun; Huang, Jinyuan; Zhou, Changyong; Xie, Tao; Tong, Jinnan; Choo, Brian (2013), "Exceptional vertebrate biotas from the Triassic of China, and the expansion of marine ecosystems after the Permo-Triassic mass extinction", Earth-Science Reviews, 125: 199–243, Bibcode:2013ESRv..125..199B, doi:10.1016/j.earscirev.2013.05.014, ISSN 0012-8252
Chen, L. D.; Cuny, G.; Wang, X. F. (2007), "The chondrichthyan fauna from the Middle-Late Triassic of Guanling (Guizhou province, SW China)", Historical Biology, 19 (4): 291–300, Bibcode:2007HBio...19..291C, doi:10.1080/08912960701248234
Tong, J.-N.; Lui, Z.-L. (2000), "The Middle Triassic stratigraphy and sedimentary paleogeography of South China", Albertiana, 24: 37–47
