MORPHOLOGY OF A PATHOLOGICAL STROPHOMENID FROM THE CINCINNATIAN WAYNESVILLE FORMATION, BROOKVILLE, INDIANA, USA

Pathologies are direct evidence of organism-environment interaction, and can be an indicator of water quality, and health of marine ecosystems. Brachiopods commonly exhibit pathologies that yield useful information regarding environmental changes and conditions of marine benthic communities. Here we describe the morphology, significance, and causation of shell deformation in a specimen of the strophomenid brachiopod Rafinesquina from the Cincinnatian Waynesville Formation (Upper Ordovician C5 sequence) of Brookville, IN that possesses crenulations on the commissure of the shell margin. A differential diagnosis was conducted for the brachiopod specimen, supported through research of other pathologies within similar bivalved organisms, with known etiologies. The criteria considered during research included traumatic injury, contaminants within the ecosystem, parasitic and bacterial infection, and overcrowding. causes such as infection from a parasite or prokaryote are also considered. Continued comparisons and histological sectioning of the afflicted Rafinesquina may also yield details pertaining to a probable diagnosis.