Nice Fossil Gastropod (Cyclonema) - Ohio

This is a nice Ordovician aged gastropod (Cyclonema bilix) fossil from the Arnheim Formation of Ohio. Mollusc shells are typically composed of a phosphatic substance called Aragonite. Unfortunately Aragonite does not preserve well in the Cincinnatian, so most gastropod fossils are internal molds, unlike this specimen. This piece has been cleaned under microscope using air abrasives.