贵州贞丰晚二叠世晚期的介形类

Latest Permian Ostracods from Zhenfeng, Guizhou

本文描述了贵州贞丰晚二叠世长兴组介形类化石计15属26种(包括新种8个)。这一介形类动物群与北美及我国浙江长兴等地二叠纪地层所产介形类相似,其中二叠纪的特有属种数量丰富、种类繁多。贞丰二叠系与三叠系沉积连续,介形类化石的研究为二叠系与三叠系的界线划分提供了重要的生物依据。

The ostracods described in this paper were collected in 1987-1990 from the Upper Permian Changhsing Formation at Zhenfeng, Guizhou province, China. This fauna contains 15 genera and 26 species, including 8 new species namely Coronakirkbya binodosa, Kellettina binodosa, Amphissites biambonaria, Petasobairdia unispinata, P. atopa, Ceratobairdia zhenfengensis, Acanthoscapha longicostata, A. camura. These ostracods are found in association with the fusulinids, non fusulinid foraminiferids, bra-chiopods, cephalopods and conodonts.In this region, there are many continuous Permian and Triassic sections. The Changhsing Formation, which total thickness is about 55m, can be divided into two parts based on the lithological characters and ostracod fauna:1. The lower part consists of mainly grey dark grey medium-bedded limestone. It mainly yields. Coronakirkbya binodosa, Kellettina binodosa, Amphissites biambonaria, Bairdia chasae, Petasobairdia atopa, P. unispinata, P. bicornuta, P. nantongensis, Ceratobairdia sinensis, C. zhenfengensis, Acratia olivifera.2. The Upper part consists of mainly dark, dark grey lydite and siliceous limestone. It mainly bears the ostracods: Rectobairdia applanata, Petasobairdia atopa, P. bicornuta, Bassierella obesa, Microcheilinella sp.Most of these ostracod species can be correlated with these of North America, Jiangsu, Hubei, Guizhou and Zhejiang province, China.