Monograph: Silurian Conodonts from the Yangtze Platform, South China

Silurian conodonts from several sections in the area of the Yangtze Platform, south China, are described and their taxonomy revised. Two new families, Pseudooneotodidae and Gamachignathidae, are erected, one new genus, Chenodontos, and ten new species and subspecies: Apsidognathus ruginosus scutatus, Chenodontos makros, Distomodus cathayensis, Oulodus tripus, Ozarkodina wangzhunia, Panderodus amplicostatus, Pterospathodus sinensis, Wurmiella amplidentata, Wurmiella curta and Wurmiella recava. Some additional new taxa are introduced in open nomenclature. The status of Silurian conodont biozonation in China is reviewed, and the following successive appearance biozones provisionally recognised to span the Llandovery succession in ascending order: Ozarkodina aff. hassi Biozone; Ozarkodina obesa Biozone; Ozarkodina parahassi Biozone; Ozarkodina guizhouensis Biozone; Pterospathodus eopennatus Biozone; Pterospathodus celloni Biozone; Pterospathodus amorphognathoides Biozone. The re-assessment of conodont data indicates that unequivocal Wenlock taxa have not been recorded on the Yangtze Platform and that Wenlock marine deposits, if present, are much less extensive than previously suggested. Current conodont evidence also indicates that red beds are probably developed at three levels in the Silurian of the region: upper Aeronian to lower Telychian; upper Telychian, perhaps extending into the Wenlock; Ludlow, pre-O. crispa Biozone.