New microfossils from the neoproterozoic (Sinian) Doushantuo Formation, Wengan, Guizhou Province, southwestern China

Well-preserved, three-dimensional microfossils are reported from a 3.7 m thick black phosphorite bed in the Sinian Doushantuo Formation at Wengan Phosphate Mine, Guizhou Province, southwest China. The diverse assemblage, observed in thin sections, comprises planktonic acritarchs, benthic cyanobacteria, bacteria, and thallophytes. Twenty one taxa are recognized, including 1 new genus and 4 new species. Acritarchs include Baltisphaeridium rigidum sp. nov., Vulcanisphaera phacelosa sp. nov., Comasphaeridium magnum Zhang 1984, Cymatiosphaeroides yinii sp. nov., Dicrospinasphaera zhangii gen. et sp. nov., Echinosphaeridium maximum (Yin, 1987) Knoll, 1992, Ericiasphaera sp., ?Ericiasphaera sp., Hocosphaeridium scaberfacium Zang & Walter, 1992, Meghystrichosphaeridium sp., Meghystrichosphaeridium wenganensis Chen & Liu, 1986, Polyhedrosphaeridium sp. The cyanobacteria and bacteria comprise Paratetraphycus giganteus Zhang, 1984, Gloeodiniopsis lamellosa (Schopf, 1968) Knoll & Golubic, 1979, Globophycus sp., Myxoc...