Rhipidognathid conodonts from the Early Ordovician Honghuayuan Formation of Guizhou, South China

The two oldest species of rhipidognathid conodonts, Rhipidognathus yichangensis and Bergstroemognathus extensus, are described and illustrated from the Early Ordovician Honghuayuan Formation of Guizhou, South China. Both species are interpreted to consist of a septimembrate apparatus. The form species Bergstroemognathus hubeiensis is regarded as a junior synonym of B. extensus. As currently defined, the multi-element species B. hubeiensis includes elements belonging to both B. extensus and R. yichangensis, and hence can no longer be regarded as a valid species.