ABSTRACT
Edrioasteroids occur as epibionts on strophomenid brachiopod pavements in the upper parts of Maysvillian shoaling-upward cycles in northern Kentucky and southwestern Ohio. Excavation of large surface areas of two such pavements at approximately the same stratigraphic interval from localities 34 km apart enabled analysis of species composition, size-frequency distribution, and orientation of epibionts and host shells. The Ohio population attached to predominantly disarticulated, abraded, and unoriented pedicle exteriors and brachial interiors. In the Kentucky population, small edrioasteroids clustered around the anterolateral shell margins, but no such preference was found for the Ohio population. Marginal clustering suggests that the brachiopod host was alive when colonized. Larger edrioasteroids in both populations occupied more central positions of mostly disarticulated, abraded pedicle exteriors.
