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Fossils from Monmouth County, New Jersey

Pachyrhizodus sp.

Age – Late Cretaceous; Commonality – Scarce; Size – teeth: 5 mm to ~2 cm (in New Jersey)

This was a medium to large sized bony fish which is found fairly commonly in Kansas. Here in New Jersey they are more difficult to come by. The exact species is not known, there may be a couple present. I suspect there are at least two species, although the differences in the teeth may be just because of variation, gender (unlikely), and/or age. One tooth form is more robust, while the other is slenderer. Their teeth have a smooth enamel coating, with no sign of growth cracks or striations. They have a stout look to them which can sometimes make them resemble reptilian teeth. Their apex is fairly blunt, even when pristine. They can be distinguished from reptile teeth by a slight flattening on one of their carinae. Their bases are also uniquely shaped; they have a wide but shallow indentation, unlike crocodile and plesiosaur teeth which have narrow and relatively deeper indentations. Pachyrhizodus teeth are also usually less massive than Mosasaur teeth.

Teeth

Lateral View

Lateral View

Labial View

Lingual View

Basal View

Occlusal View

A more typical tooth. Most are missing the enamel.

Lateral View

Lateral View

Labial View

Lingual View

Basal View

Occlusal View

A nice tooth with the enamel.

Lateral View

Lateral View

Labial View

Lingual View

Basal View

Occlusal View

Another nice one.

Lateral View

Lateral View

Labial View

Lingual View

Basal View

Occlusal View

A large tooth at 1.6 cm. Most are around 9 mm.

Lateral View

Lateral View

Labial View

Lingual View

Basal View

Occlusal View

A small tooth. This one is around 5 mm.

Lateral View

Lateral View

Labial View

Lingual View

Basal View

Occlusal View

The teeth above look like the typical Pachyrhizodus teeth found here. This tooth has a different form. It is possibly a different species. It could also easily be a variation or from a different jaw position.

Lateral View

Lateral View

Basal View

Occlusal View

Kind of a strange tooth. It somewhat resembles a Croc/Mosasaur tooth, but has some different features, including a very flat base. It is most likely a fish tooth. It most closely resembles a Pachyrhizodus out of the known species, but there is a good chance that it is something else.

Lateral View

Lateral View

Basal View

Occlusal View

Another different tooth. This one is definitely from a fish, but there is a chance it isn’t from a Pachyrhizodus sp.

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