18种龟类的头骨解剖分析.pdfVIP

An anatomical study of 18 kinds of turtle skull Abstract The Chelonia of the fossil turtles first appeared about 200 million years ago. The kinds of turtles are only 15 families, 96 genera, and 317-331 species in the whole world. There are 6 families, 22 genera and 36 species in China. Morphological study is the basis of turtle taxonomy, and is the main contents of turtles system before the rise of molecular systematics. By the mid first Century, with the development of chromosome preparation technique, some taxonomic and systematic discussion of turtles were studied on the karyotype of the problem. At present, the research on classification and system about the turtles are mainly concentrated in the area of molecular systems. For a long time, there have been different opinions on the classification of turtles. Some controversial problems still exist in the classification and phylogenesis of turtles. For an instance, ambiguous classification between genus Cuora and genus Cistoclemmys. Some scholars think that Cuora should be split into two genera while some argue that the Cuora flavomarginata and Cuora galbinifrons are more appropriately put into Cuora. And others propose to abolish the original Cistoclemmys and Pyxidea. Therefore, the classification of terrapin still needs further researches. This research are on 6 families, 15 genera and 18 turtle class, observing and analyzing the anatomy of the skeletal system, discussing the phylogeny and classification problem on application of cladistics, and verifying the development results from morphological cha