A diverse chitinozoan record from the Upper Ordovician (Katian) of the Cincinnati region (Kentucky, USA)

Biostratigraphic characterization of the Upper Ordovician in the Cincinnati region is complicated by several issues including provincialism of conodonts and graptolites, their facies dependence, the lack of biostratigraphical resolution for conodonts, and the absence of graptolites from many sections. Our study of the MY-14-01 core from Maysville (Kentucky, USA), type area for the Maysvillian Regional Stage of the Cincinnatian Series, suggests that chitinozoan biostratigraphy has the potential to strengthen the existing biostratigraphic framework based on conodonts and graptolites. Our samples usually yielded abundant, well-preserved chitinozoans in diverse populations. Many of these taxa are present in biostratigraphic reference sections from other parts of the Laurentian paleocontinent (Quebec and Anticosti Island, Canada, and Nevada, USA) and Avalonia (England and Wales). Here we provide systematic descriptions of selected chitinozoan taxa, including those of 12 new species: Conochitina rudis, Tanuchitina hooksae, Belonechitina laciniata, Hercochitina andresenae, Hercochitina anningae, Hercochitina edingerae, Hercochitina krafftae, Hercochitina polygonia, Hercochitina tharpae, Clathrochitina mangle, Angochitina bascomae, and Nevadachitina soufianei. One new name combination is proposed: Belonechitina duplicitas (Martin, 1983). This study provides a robust starting point for further advancing the Katian chronostratigraphic framework of the U.S. midcontinent.