SHARK SPECIES IN THE UPPER CRETACEOUS OF NORTHERN TEXAS

At the contact between the Austin Calk and Eagle-Ford Shale in Ellis County of north Texas, a condensed section exist which contains a plethora of Cretaceous age shark teeth. This condensed section is an erosional feature with limited stratographic significance. The abundance of shark teeth exists only at localities where the section has been preserved. Identification of shark species was done through traditional methods. Assigning an approximate age to the teeth and condensed section was done using planktonic forams collected at the field area. As these specimens are not preserved in the same adundance in older or younger rock, it is presumed that environmental conditions favorable to a rich shark population only existed during this time.