Taxonomic And Biostratigraphic Study On The Latest Permian Albaillellaria (Radiolaria) From South China

Albaillellaria is a characteristic kind of deep-water radiolarian. It first appears in Silurian, and gets to its acme in Late Devonian. At last it disappears at the end of Permian. Albaillellaria evolved rapidly with a wild distribution in the global paleocean. Therefore, it plays an important role in the division and correlation of global deep-water faces strata. In the latest three decades, plenty of documents about taxonomy of Albaillellaria have been accumulated in many places of the world. Abundant taxonomic documents of Albaillellaria advanced researches on Permian radiolarian biostratigraphy. Holdsworth and Jones (1980) first proposed Permian radiolarian assemblages mainly based on the presence of albaillellids. Subsequently, Permian radiolarian zones in Japan, European Tethys, North American, Southern China and Thailand etc. were respectively recognized. Furthermore, the taxonomic and biostratigraphic works on Permian albaillellids have improved studies concerning the evolutionary pattern of radiolarians during the Permian and Triassic transitional stage.However, previous researches have seldom dealt with Albaillellids at the end of Late Permian, especially near the Permian-Triassic Boundary. The work on the Dongpan Section (southwest Guangxi) and the Sidazhai Section (south Guizhou) in this thesis contributes more new materials to the study in that field.From 2002 to 2004 we made fieldwork studies several times in Liuqiao area, County Fusui, Guangxi. During the Latest Permian this area is in an aulacogen with a great deal of deep-water sediments. The Dongpan Section, in which a well-preserved latest Permian radiolarian fauna was found, comprises the Dalong Formation and the Luolou Formation without interval. Lithologically, the lower part of Dalong Formation is mainly composed of muddy siliceous rocks, bedded siliceous rocks with intercalations of claystones, yielding abundant radiolarians and a few foraminifera, ostracods and brachiopods; the upper part, of siliceous mudstones with thin intercalations of claystones. Two genera and fifteen species belonging to Albaillellidae are recognized and described from the lower part of Dongpan Section, including three new species and one new subspecies, namely Neoalbaillella minuta new species, Albaillella flabellata new species, Albaillella fida new species and Albaillella yaoi longa new subspecies.In the Dongpan Section, N. optima and A. triangularis are the dominant species of Albaillella...