Two Nurse Shark Teeth

[fossilsonwheels]

First tooth in question is from the Eocene Bashi Formation, Mississippi. Both Nebrius and Ginglymostoma are described in the formation. With this tooth, I think it’s  Ginglymostoma but I figured it was better to post it and get some additional opinions. It’s around 5-6mm. 

[fossilsonwheels]

The next one is from the Cretaceous Severn Formation. There are, to my knowledge, 3 Nurse Sharks in that fauna. I don’t believe this is Plicatoscyllium. That leaves Ginglymostoma or Nebrius. I think that central cusp is a little big for a Nebrius but I’m not 100% sure. Small tooth at 5-6mm or so. 

[Dino9876]

Hi,

I can only tell you my ID based on recent teeth, but after that I would say that your 1st tooth is definitely a Ginglymostoma sp.

These 3 large denticles match 100% with the recent Ginglyostoma cirratum teeth in my collection. All Nebrius sp. teeth I have (including in jaws) look different.

For comparison (this is posterior one, your tooth seems to be more anterior):

 

Basend on the 4-5 cusps of the second tooth, I would tend more to Nebrius sp. here, but I´m not sure, because the tooth seems to be very worn. But the shape matches exactly with the Nebrius ferrugineus teeth in a jaw I have and some isolated teeth. The central cusp can be very large in (modern) Nebrius ferrugineus too.

Here is a similar Nebrius ferrugineus tooth from my collection:

 

Best regards from Germany

Edited December 29, 2022 by Dino9876
misspelling

[fossilsonwheels]

On 12/29/2022 at 1:03 AM, Dino9876 said:

Hi,

I can only tell you my ID based on recent teeth, but after that I would say that your 1st tooth is definitely a Ginglymostoma sp.

These 3 large denticles match 100% with the recent Ginglyostoma cirratum teeth in my collection. All Nebrius sp. teeth I have (including in jaws) look different.

For comparison (this is posterior one, your tooth seems to be more anterior):

 

Basend on the 4-5 cusps of the second tooth, I would tend more to Nebrius sp. here, but I´m not sure, because the tooth seems to be very worn. But the shape matches exactly with the Nebrius ferrugineus teeth in a jaw I have and some isolated teeth. The central cusp can be very large in (modern) Nebrius ferrugineus too.

Here is a similar Nebrius ferrugineus tooth from my collection:

 

Best regards from Germany

Thanks for the examples and input. I’ve got a Severn tooth that fits well Ginglymostoma, one that fits well with Nebrius and the one in the picture that could be either or lol