This study investigates a bioerosional process in which concave tubular “half-borings” are found on the basal attachment surface of trepostome bryozoans and the exposed surfaces of brachiopods (primary Rafinesquina) and bivalves in the Upper Ordovician of the Cincinnati area. All specimens were collected from exposed Upper Ordovician strata of the Cincinnatian Arch found in Richmond, Indiana and Florence, Kentucky. The ichnotaxa seen in the specimens are either Trypanites or Palaeosabella. The “half-borings” are assumed to have been created by a boring organism that was able to differentiate between the shell structures of the encrusting bryozoan and its host (brachiopod or bivalve) and make its dwelling at the interface between the two skeletons. The methods used included making acetate peels of specimens with the encrusting bryozoan with its host still attached. This research is an important first step in re-evaluating sclerobiont-host relationships and the bioerosional processes that follow in the Upper Ordovician of the Cincinnati area.


Wilson, Mark




Environmental Sciences

Publication Date


Degree Granted

Bachelor of Arts

Document Type

Senior Independent Study Thesis



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