Extinct Mackerel Shark
The teeth of Protolamna borodini are small, averaging averaging about ¼ inch in length with a maximum size of just under ½ inch. This species has a deep “U” shaped root, a large single triangular cusplet on each shoulder and strong basal wrinkles on the labial face of the crown. There is a strong lingual protuberance, which appears quite exaggerated. There is no nutrient grove. Because of their small size most specimens will fall through the standard ¼ inch screen. The large cusplets and root lobes seem particularly prone to damage. Protolamna borodini is not easily confused with any other species in the NJ area.
Typical finds. The long roots and cusplets are prone to damage.
Because of their small size these teeth will normally