Speciation of the genus Arthricocephalus Bergeron, 1899 (Trilobita) from the late Early Cambrian and its stratigraphic s

The genus Arthricocephalus Bergeron,1899 is revised, and Halipanktos Balker & Peel, 1997 is suggested here as a senior synonym. The subgenus Arthricocephalus (Arthricocephalites) Chien & Lin in Lu et al., 1974 is considered as a separate genus.Of the 20 previously assigned species of Arthricocephalus ( Arthricocephalus ) Bergeron, 1899, Arthricocephalus ( Arthricocephalites )Chien & Lin in Lu et al., 1974, Arthricocephalus (Euarthricocephalus) Ju, 1983 are lumped into eight species. The speciation trend of Arthricocephalus and Arthricocephalites is demonstrated based on their stratigraphic occurrences. It not only enhances the resolution of the biostatigraphic zonation in the uppermost Lower Cambrian, but also represents a potential candidate to define the Duyunian stage. The base of the stage is suggested at the first appearance datum (FAD) of Arthricocephalus chauveaui Bergeron, 1899 within the evolutionary lineage from Ar. jiangkouensis Yin in Yin & Li, 1978 to Ar. chauveaui in a global scale.

作 者： YUAN Jinliang ZHAO Yuanlong YANG Xinglian   作者單位： YUAN Jinliang(Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, China)

ZHAO Yuanlong,YANG Xinglian(College of Resource and Environment of Guizhou University, Guiyang 550003,China) 

刊 名： 自然科學進展（英文版）  SCI 英文刊名： PROGRESS IN NATURAL SCIENCE  年，卷(期)： 2006 16(6)  分類號： N1  關鍵詞： late Early Cambrian   Duyunian stage   speciation of Arthricocephalus and Arthricocephalites   biostratigraphy