• 责任者：Mu Lin (Nanjing Institute of Geology and Palaeontology ; Chinese Academy of Sciences ; Nanjing 210008 ; China)
• 刊名：Acta Palaeontologica Sinica
• 出版年：2013
• 卷期：52(4)
• 关键词：菊石超目 ; Ammonoidea ; 外壳 ; exoskeletons ; 系统演化 ; phylogeny ; 中国 ; China
• 页码：p.459-466
• 图表：4 illus., 1 table, 26 refs.
• 分类号：1102
• issnNo：ISSN0001-6616
• isbnNo：CN32-1188/Q

     This study is based on ammonoid records repor morphological analysis bas the Kungurian-Roadian ted from China. A ed on Raup＇s （1966）method was used to analyze the evolutionary history of shell morphology of ammonoids. Three parameters are referenced： whorl expansion rate （W=（d/e）^2）, whorl overlap degree （D=c/d）, and the shape of the whorl cross-section （S=b/a）. These parameters have adaptive significance because they determine a number of hydrostatic and hydrodynamic parameters of the shell. Ammonoid shell morphospace analysis indi- cates that the Kungurian ammonoids morphospace is divided into three main types. Type 1 has D value between 0-0. 1 and W rate between 1. 5- 2.5 which is consistent with Type A of Saunders. Type 2 with D = 0-0. 1 and W = 3 is generally consistent with F type of Saunders. Type 3 with D =0. 5-1. 5 and W=4-5, is comparable with F type, but has a larger W value. Roadian ammonoids morphospace could be divided into two types： One has, D between 0. 1-0. 25 and W between 1-2 representing A type; another has D between 0.4-0.6, W between 1-2, representing C type. In terms of morphospace, the general trend from Kungurian through Roadian is transitional, suggesting no major external interruptions. How- ever, the morphospace had also undergone a signi- ficant change. There is an obvious a space of mor- phological broader position occupied in Roadian, representing a new direction in evolution, in which the shell is not only more evolute, but the shell ex- pansion rate is also decreased. The same trend is also reflected globally in the Early Permian-Middle Permian ammonoid shell D-W density contours. This indicates that in spite of more endemic species from Kungurian to Roadian in China, which are difficult to be applied for international correlation, it can be compared with those in other regions of the world from the morphospace point of view.