Caseodus species
  
Order: Eugenedontia 
Super Family: Caseodontoidea 
Family: Caseodontidae
Genus: Caseodus
  
The photo shows two different views of a tooth from a member of the Caseodus generia.  This genus include a large number of specimines in the "Mecca Fauna" that represent at least 3 species of sharks. 
Approximate Age: 310-312 million years old.
Location of Discovery: Peabody Coal Co. Marissa Mine - Washington County., Illinois