NJfossils.com

Cow-Nosed Ray (Brachyrhizodus wichitaensis)

XXXXXXXX

Teeth

This is one of the central medial teeth. The root foramina stand out well on this one.

Another central medial tooth.

This medial tooth has less root sections and is from a different position.

An outer medial tooth showing a heavy in vivo wear pattern.

This outer medial tooth has less in vivo wear on it.

Another outer medial tooth with a different shape.

This outer medial tooth pretty much has no wear at all.

This is a lateral tooth. The lateral teeth have a different shape than any position of the medial teeth. They do not have the double chevron shape and instead are more amorphous. They can sometimes be confused with Pseudohypolophus mcnultyi teeth. This one seems to show some root foramina in between the two root lobes.

Dermal Denticles

The rays Rhombodus laevis, Brachyrhizodus wichitaensis, and Pseudohypolophus mcnultyi had denticles which were relatively large (~ 1/8 – ¾ inches). They were approximately tear-dropped in shape and had a protrusion around the middle, when looking at them in occlusal view. The denticles of B. wichitaensis were said to differ from R. laevis denticles by the presence of small dots on the surface. R. laevis had striations. These ideas are not entirely clear. The small dots/bumps fall off easily pre-fossilization. It might be that the denticles of both rays looked very similar. The denticles of P. mcnultyi are said to have resembled the denticles of B. wichitaensis. These denticles’ commonality is “very uncommon.” Associated remains need to be found in order to attribute the denticles to a specific type of ray.

Content copyright 2018: njfossils.com. All rights reserved.