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Fossils from Monmouth County, New Jersey

Mackerel (Protolamna borodini aka Cretodus borodini aka Plicatolamna borodini)

Age – Late Cretaceous; Commonality – Uncommon; Size – avg: 1/4 inch, max: 1/2 inch

These teeth are similar to the other two mackerel sharks’ teeth. The difference is that these teeth are significantly smaller and have exaggerated features. Their lingual protuberances stick out more than on any other species. The root is large in comparison to the crown. They also possess strong wrinkles on the labial side and sometimes on the lingual side of the crown when unworn. Another feature is that they have a slight flattening of the crown towards the tip. These teeth are very prone to breakage and usually have in-vivo wear, a broken root, or a worn down lingual protuberance.

Anterior Teeth

Lingual View

Labial View

Profile View of Mesial Side

Profile View of Distal Side

Occlusal View

Basal View

This tooth is a lower first anterior P. borodini. It has long root lobes, a large lingual protuberance, and no curvature in its crown.

Lingual View

Labial View

Profile View of Mesial Side

Profile View of Distal Side

Occlusal View

Basal View

This tooth is a lower anterior. Note the symmetrical shape and straight crown. However, it is not a lower first anterior because its lingual protuberance does not jut out much.

Lingual View

Labial View

Profile View of Mesial Side

Mackerel Shark Cretaceous (Protolamna borodini) Anterior tooth, New Jersey

Profile View of Distal Side

Occlusal View

Basal View

This tooth is an upper anterior. Upper anterior P. borodini teeth are more distally curved than the lowers.

Lateral Teeth

Lingual View

Labial View

Profile View of Mesial Side

Profile View of Distal Side

Occlusal View

Basal View

Lateral teeth are relatively wider when compared to anterior teeth. This tooth is an upper lateral. It has some slight wrinkles at the base of the lingual side of its crown, which is unusual (usually these teeth only have these folds on the labial face of the crown).

Lingual View

Labial View

Profile View of Mesial Side

Profile View of Distal Side

Occlusal View

Basal View

This tooth is another upper lateral. It has a small bump near the base of the mesial carina; this bump almost looks pathological, but it is probably not exaggerated enough to be called that.

Lingual View

Labial View

Profile View of Mesial Side

Profile View of Distal Side

Occlusal View

Basal View

This tooth is a lower lateral. It has the asymmetrical shape of lateral teeth, but is less angled. Notice that its lingual protuberance is fairly exaggerated; this should help differentiate between lower laterals and upper anteriors, which have a more reduced lingual protuberance.

Lingual View

Labial View

Profile View of Mesial Side

Profile View of Distal Side

Occlusal View

Basal View

This tooth is another lower lateral.

Lingual View

Labial View

Mackerel Shark Cretaceous (Protolamna borodini) Lateral tooth, New Jersey

Profile View of Mesial Side

Profile View of Distal Side

Occlusal View

Basal View

This tooth is a lower lateral tooth that would have been situated closer to the posterior tooth files.

Posterior Tooth

Lingual View

Labial View

Profile View of Mesial Side

Mackerel Shark Cretaceous (Protolamna borodini) Posterior tooth, New Jersey

Profile View of Distal Side

Occlusal View

Basal View

This posterior tooth (most likely a lower) possesses strong folds on the main crown and cusplets on both the labial and lingual sides.

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