Well preserved silicified ostracodes have been found in a presumably allochthonous detrital limestone lens within argillaceous limestones of the Muhua Formation of the Muhua section in Guizhou Province, South China. Some 32 species have been identified and assigned to 24 genera. Houhongfeiella microspinosa gen. et sp. n., Gortanella ruggierii sp. n., Coryellina grammi sp. n., Coryellina advenoides sp. n., Guerichiella coeni sp. n., Knightina jiqiangi sp. n., Hypotetragona? sinica sp. n., Cavellina robinsoni sp. n., Cavellina guizhouensis sp. n., Sulcella jonesi sp. n., Bairdia cheni sp. n., and Bairdiacypris wangi sp. n. are proposed. Similarity at the generic level exists between ostracode faunas of the Early Carboniferous formations of China, Australia, Europe, Asia and North America. Unlike the ostracodes from the underlying nodular limestones of the Wangyou Formation that represent the basinal 'Thuringian ecotype' fauna, the ostracode assemblage of the studied interval belongs to the 'Eifelian ecotype' and is indicative of a well-oxygenated, normal salinity, high-energy shallow-water environment. The term calcified internal rim is proposed for the internal structure developed along the free margin in some palaeocopid ostracodes. It differs from the calcified inner lamella of podocopids mainly in the lack of marginal pore canals, lack of vestibulae and lack of clear separation from the outer lamella.

Key words: Ostracoda, taxonomy, morphology, palaeoecology, Early Carboniferous, South China.

Ewa Olempska [olempska@twarda.pan.pl], Instytut Paleobiologii PAN, ul. Twarda 51/55, PL-00-818 Warszawa, Poland.