Taxonomic Study On Late Changxingian Radiolarian From Fusui, Guangxi And Chaohu, Anhui

This paper has three parts: (1) taxonomic study on the radiolarian from Fusui, Guangxi (2) taxonomic study on the radiolarian from Anhui, Chaohu (3) the method to observe the internal structure of radiolarian. The large progress was made as follows in brief.The region of southwestern Guangxi is a part of the Youjiang Basin and shows being of archipelagic ocean (sea). The deep water marine PTB sections were well developed in the southwestern Guangxi. This paper reports a radiolarian fauna from the from the upper Dalong Formation, Fusui, Guangxi. One new genus and two new species, is described.Pingdingshan section, is one of the candidate stratotype sections of the Induan-Olenekian Boundary. The Lower Triassic intervals in Pingdingshan section had been investigated in detail and received much attention. However, the Changhsingian Dalong Formation has been relatively little studied, and especially, there have been few reports on the Changhsingian radiolarian fauna from this section.This paper reportes a radiolarian fauna from the upper Dalong Formation, Chaohu, Anhui Province, including 15 genera 23 species. One new species, Copicyntra tongi, is described. Comparison of the fauna, lithology and biotic associations with those from Meishan and Dongpan sections shows that the Dalong Formation in Pingdingshan section is deposited in a deep-water shelf basin, about 60-200m in depth. On the basis of the biotic composition, diversity and morphology, the microfossil fauna from Chaohu section can be divided into three sedimentary assemblages and their extinction processes are discussed.The earliest and most comprehensive taxonomic classification of radiolarians was published by Haeckel in 1881. This classification was based on the geometry of the shell, the number of segments(nassellarians) or concertric shells(spumellarians), the presence and the number of feet(nassellarians) or arms(discoidal spumellarians), the presence or absence of a terminal aperture(nassellarians), etc. The classificatory system built by Haeckel had, from its publication until now, a two side effect on the development of the understanding of radiolarians: on the positive side, it has provided a comprehensive, simple, geometric framework within which to record most of the radiolarians ; on the negative side, this purely geometric classification inhibited for a long time the development of any alternative, more natural system.More recent attempts have tried, however, to develop natural and coherent bases for a renewed radiolarian classification. The taxonomic system published by De Wever is based on: 1. presence or absence of an initial spicule and its structure; 2. relationship of the initial spicule to the first shell; 3. morphology of the first shell; 4. growth patterns of the skeleton; 5. number of shells,chambers or segments; 6. number of spines or arms; 7. presence of an aperture or pylome.Examinations of the internal structures of microfossils provide important information about phylogenetic relationships and growth patterns. The internal structure of radiolarians provided important information on phylogenetic relationships and classificationdue to the varying internal structures that are characteristicwithin each family or subfamily. An array of disk-shaped forms that appears to be uniform may in fact contain many different internal structures. This paper discussed the methods observe the internal structure of radiolarian and improved the methods. We observed the internal structure of Hegleria, and defined the characters of Hegleria mammilla.