海南岛含杜内早期腕足动物群层的发现

EARLY TOURNAISIAN BRACHIOPOD FAUNA FOUND IN THE HAINAN ISLAND

白沙县金波附近的 Spirifer subgrandis Rotai,Unispirifer extensus Tan,Fusella tornacensis (Koninck) ,Punctospirifer insculptus (Phillips) ,Marginatia huaqiaoensis Tan,Palaeochoristites sp.,Megachonetes sp.,Plicochonetes sp.,Schuchertella sp.,Pustula sp.,Sentisia sp.,Crurithyris sp.,Rhipidomella spp.等是海南岛首次发现的最丰富的杜内早期腕足动物群。据此 ,该地区含化石的南好组第四段确定为下石炭统岩关阶 ,似可与湖南马栏边组、黔南汤耙沟组等层位对比。以石燕贝类最繁盛、长身贝类数量少为特征的该动物群与华南其他地区同期腕足动物群存在诸多相同属种但又有明显差异。

Very abundant brachiopods including Spirifer subgrandis Rotai,Unispirifer extensus Tan,Fusella tornacensis(Konick),Punctospirifer insculptus(Phillips),Marginatia cf.Huaqiaoensis Tan,Palaeochoristies sp.,Megachonectes sp.,Plicochonectes sp., Schuchertella sp.,Pustula sp., Sentosia sp., Crurithyris sp., and Rhipidomella sp.were found for the first time in the Jinbo area of the western Hainan Island. This fauna indicates an Early Tournaisian age. Accordingly,the fossil-bearing rocks,the Member 4 of the Nanhao Formation is now placed in the Carboniferous Aikuanian Stage, where no fossils have been found in the past.This fauna is characterized by the abundance of spiriferoids and the sparseness of productoids,and differs from the coeval brachiopod faunas of South China.