A very rare tooth from the Pungo River formation, the bramble shark, Echinorhinus blakei AGASSIZ, 1856a, is very similar to both the modern E. brucus (BONNATERRE, 1788) and E. cookei PIETSCHMANN, 1928. The two modern species are separated by the shape and size of the 'brambles' or dermal denticles which cover their body.

E. brucus has larger dermal denticles which have circular bases and are often fused together into large clusters. E. cookei has small (5 mm or less) individual dermal denticles with stellate bases. A few such denticles (but none of the E. brucus type) have been found in the mine indicating that E. blakei is closer to the modern E. cookei.

The teeth are similar in both jaws with thin rectangular roots similar to those of the cow sharks. One or more cusps are splayed out laterally with juveniles having less cusps than adults. There are no distinctive anterior or posterior teeth.

Echinorhinus blakei Lingual (right) & labial (left) views of incomplete teeth and dermal denticle from the Pungo River formation. The middle (tooth) specimen has very fine serrations (not visible in the scan) and is 14+ mm in width.