Dendroid graptolites from the Lower Ordovician (Tremadocian) of the Yichang area, Hubei, China

摘要

The Yichang area of Hubei Province, China provides important information on Lower to Middle Ordovician fossil faunas and is a center for research on Ordovician graptolites due to the sometimes excellent preservation of the copiously available material. New material collected during a research project on Lower to Middle Ordovician biota in the Yichang Region provided among others specimens a number of dendroid (benthic) graptolites of the genera Acanthograptus, Aspidograptus, Dendrograptus, and Koremagraptus showing unexpected and unknown structural features, useful for structural and evolutionary investigations.