Unknown Elasmobranch Pennsylvanian Shark Tooth

The late Pennsylvanian and early Permian dark shale deposits of the Midwest have produced some exceptional examples of fossils of the elasmobranches, the grouping to which sharks and rays belong. These horizons are the result of deep water deposits during marine transgressions into the interior of the continent that are known as cyclothems. These black shales represent deposition in a low to no oxygen environment which allowed for exceptional preservation of specimens that were free from predation and scavenging. This is a fine example of a tooth from an indeterminate elasmobranch. The tooth does not look suited to grasping prey in the way that those of Cladodonts are. It was most likely employed in crushing the shells of invertebrates.