Jawed polychaetes from the upper Sylvan shale (Upper Ordovician), Oklahoma, USA

A jawed polychaete fauna from the upper 30 m of the Upper Ordovician Sylvan Shale (Richmondian, Ashgill) of Oklahoma is described, based on recovered scolecodonts (polychaete jaws). The fauna includes members of six families: Paulinitidae, Ramphoprionidae, Polychaetaspidae, Atraktoprionidae, Hadoprionidae, and Kalloprionidae. Ten species are identified and one new paulinitid species, Kettnerites (Aeolus) sylvanensis, dominates. The low-abundance and relatively low-diversity Sylvan Shale fauna differs from approximately coeval ones of both Laurentia and Baltica, particularly by its high relative frequency of paulinitids. The scolecodonts are associated with chitinozoans, as well as some enigmatic organic-walled microfossils. Conodonts are extremely rare, with Plectodina tenuis, Amorphognathus sp., and Dapsilodus sp. identified.