Caritodens demissa Pelecypod Fossil

 

The Caritodens demissa (Conrad, 1842) pelecypod fossil found in Jefferson County, Indiana USA (near Madison). Fossil dates to the Ordovician Period. The book Index Fossils of North America by Hervey W. Shimer and Robert R. Shrock 1944 lists this fossil as Pterinea demissa (Conrad, 1842) of the Upper Ordovician Period (Maysville-Richmond). It is described as "Distinguished by its strong concentric growth lines and large anterior ear." The genus Pterina was named by Georg August Goldfuss (1782-1848) in 1832. Original species named Avicula demissa in 1842 by Timothy Abbott Conrad (1803-1877) in the Journal of Academy of Natural Sciences in Philadelphia Volume VIII page 242, plate XIII, figure 3.

Thanks to Kenny for the image.