A new trilobite species from the upper Rhuddanian (lower Silurian) of South China, and its biogeographical implications

Abstract

Wei, X. & Zhan, R. B., 20 September 2018. A new trilobite species from the upper Rhuddanian (lower Silurian) of South China, and its biogeographical implications. Alcheringa 43, 33–42. ISSN 0311-5518.Xin Wei [xwei@nigpas.ac.cn]. State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing, 210008, PR China; University of Science and Technology of China, Hefei, 230026, PR China; Renbin Zhan [rbzhan@nigpas.ac.cn], State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing, 210008, PR China; University of Chinese Academy of Science, Beijing, 100049, PR China.Anacaenaspis yanpingensis sp. nov., from the lower Niuchang Formation (upper Rhuddanian, lower Llandovery, lower Silurian), is the first record of this genus from South China. The biogeographical distribution of Anacaenaspis and some other trilobite genera from South China (e.g., Gaotania, Hyrokybe, Aulacopleura and Raphiophorus) in the Llandovery evidences faunal exchanges between Avalonia–Baltica, Laurentia, Australia and South China. We attribute these dispersals to prevailing ocean currents, and especially equatorial countercurrents, which would have propagated dispersals during the Rhuddanian, shortly after the end-Ordovician mass extinction.