Extinct Mackerel Shark
Protolamna borodini (Cappetta & Case)
aka Cretodus borodini

Age - Cretaceous  Commonality - Uncommon

The teeth of Protolamna borodini are small, averaging averaging about   inch in length (6-7 mm) with a maximum size of just under 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. The root has no nutrient grove and a strong lingual protuberance, which appears quite exaggerated.  Because of their small size most specimens will fall through the standard inch screen. The large cusplets and root lobes seem particularly prone to damage. Protolamna borodini can easily be confused with the smaller catshark Scyliohinus.



Protolamna borodini

The teeth of Protolamna borodini are small, averaging averaging about
 xxx mm or about inch in length
Monmouth County, NJ.


A distinct characteristic of this species is the exaggerated
  lingual protuberance.
Monmouth County, NJ.


Basal wrinkles on the labial face.
Occasionally these wrinkles or folds may also be present
on the lingual surface of the crown.



Comparison of Protolamna borodini (Left) and
Scyliorhinus (Right).
Both have strong folds at the base of the crown, on Scyliorhinus the crown
 is narrow and overhangs the root with multiple cusplets.


Typical finds. The long roots and cusplets are prone to damage.


Because of their small size these teeth will normally fall through
the standard 1/4 mesh screen normally used in the streams of
Monmouth County.
This is the only specimen I have found using the common 1/4
inch mesh screen.



Protolamna borodini

Protolamna borodini

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