Upper lower Cambrian (provisional Cambrian Series 2) trilobites from northwestern Gansu Province, China

Estonian Journal of Earth Sciences

Per Ahlberg¹  Niklas Axheimer²  Jan Bergström†³  Zhou Zhiqiang⁴ 

[1] [e-mail];Department of Geology, Lund University, Sölvegatan 12, SE-223 62 Lund, Sweden;Department of Palaeozoology, Swedish Museum of Natural History, P.O. Box 5007, SE-104 05 Stockholm, Sweden;Xian Institute of Geology and Mineral Resources, 438 East You Yi Road, Xian 710054, Peoples Republic of China;

关键词: Trilobita;    taxonomy;    palaeobiogeography;    lower Cambrian;    Cambrian Series 2;    Beishan;    Gansu Province;    China.;   

DOI  :  10.3176/earth.2014.12

来源: DOAJ

【 摘 要 】

Upper lower Cambrian (provisional Cambrian Series 2) trilobites are described from three sections through the Shuangyingshan Formation in the Beishan area, northwestern Gansu Province, China. The trilobite fauna is dominated by eodiscoid and corynexochid trilobites, together representing at least ten genera: Serrodiscus, Tannudiscus, Calodiscus, Pagetides, Kootenia, Edelsteinaspis, Ptarmiganoides?, Politinella, Dinesus and Subeia. Eleven species are described, of which seven are identified with previously described taxa and four described under open nomenclature. The composition of the fauna suggests biogeographic affinity with Siberian rather than Gondwanan trilobite faunas, and the Cambrian Series 2 faunas described herein and from elsewhere in northwestern China seem to be indicative of the marginal areas of the Siberian palaeocontinent. This suggests that the Middle Tianshan–Beishan Terrane may have been located fairly close to Siberia during middle–late Cambrian Epoch 2.

【 授权许可】

Unknown