The Moscovian staffellids from Ziyun County, Guizhou Province, China: the effects of sedimentary environment on fusulinid taxonomic discrepancy

Abstract Carboniferous fusulinids, including 23 species in 7 genera, are identified from the Lumazhai area, Ziyun County, southern Guizhou, China. They are mainly composed of Staffella, Pseudoendothyra, Pseudostaffella, and Fusulinella, which suggest a late Moscovian age. The fusulinid assemblage is characterized by the dominance of staffellids that shows a different composition from the other late Moscovian fusulinid faunas reported in South China. Combined with microfacies analysis, we suggest that the different faunal composition most likely resulted from varying depositional settings, implying the sensitivity of fusulinids to sedimentary environments. This phenomenon of “synchronous but heterogeneous fusulinid biofacies”, caused by changing sedimentary condition, is significant in explaining taxonomic variation especially with limited collection of fusulinid fossils.