NJ Brook Reptile Tooth Identification

[historianmichael]

I found this tooth several years ago in the Ramanessin Brook in Monmouth County, NJ. I initially thought it was from a mosasaur, but now I am having second thoughts. Any help would be greatly appreciated. Thank you.

 

 

[Rockwood]

Most likely mosasaur.

What is it that is making you question it ?

[Fossildude19]

+1 for mosasaur. 

[Troodon]

Yep mosasaur 

[FossilsAnonymous]

I'm on the Mosasaur team.

[frankh8147]

Looks mosasaur to me too - nice!!

[Bone guy]

That's a very nice mosasaur tooth. Congrats! 

[Jeffrey P]

Another vote for mosasaur.

[Carl]

Want another mosasaur vote? You got it.

[The Jersey Devil]

Like everyone else said, it's Mosasaur. The only other thing they can be confused with when they are complete is Croc teeth. Juvenile Mosasaur teeth have the same shape as some of Croc teeth here - they are cone-like and average under a half inch in size.

[Carl]

29 minutes ago, The Jersey Devil said:

Like everyone else said, it's Mosasaur. The only other thing they can be confused with when they are complete is Croc teeth. Juvenile Mosasaur teeth have the same shape as some of Croc teeth here - they are cone-like and average under a half inch in size.

There's an even more easily confused tooth you find in the brooks: Pachyrhizodus (a fish). After I learned to recognize it I went back to all my mosasaur teeth and found 3 or 4 Pachyrhizodus teeth hiding in there.

[MarcoSr]

I have several thousand croc teeth but only a couple of mosasaur teeth so I don't know a lot about mosasaur teeth.  But I'm curious how so many TFF members can make an id on a very worn tooth where cutting edges and striations are not visible and the pictures are taken at an angle where you really can't see the shape of the base of the tooth clearly or the tooth cavity.  What diagnostic features are you seeing in this tooth  @Carl @The Jersey Devil @Jeffrey P @Bone guy @frankh8147 @FossilsAnonymous @Troodon @Fossildude19 @Rockwood    that clearly confirm a mosasaur id?

 

Marco Sr.

[Bone guy]

5 minutes ago, MarcoSr said:

I have several thousand croc teeth but only a couple of mosasaur teeth so I don't know a lot about mosasaur teeth.  But I'm curious how so many TFF members can make an id on a very worn tooth where cutting edges and striations are not visible and the pictures are taken at an angle where you really can't see the shape of the base of the tooth clearly or the tooth cavity.  What diagnostic features are you seeing in this tooth  @Carl @The Jersey Devil @Jeffrey P @Bone guy @frankh8147 @FossilsAnonymous @Troodon @Fossildude19 @Rockwood    that clearly confirm a mosasaur id?

 

Marco Sr.

I would think a crocodile tooth would have a round cross section. You can see with this tooth the cross section is not perfectly round but a bit 'flattened' which is something's I've seen in other Mosasaur teeth. 

[The Jersey Devil]

29 minutes ago, Carl said:

There's an even more easily confused tooth you find in the brooks: Pachyrhizodus (a fish). After I learned to recognize it I went back to all my mosasaur teeth and found 3 or 4 Pachyrhizodus teeth hiding in there.

 

Pachyrhizodus teeth are more easily distinguished from Mosasaur teeth than Croc teeth are in my opinion. They usually don't have growth cracks or striations and have an asymmetrical appearance.

[The Jersey Devil]

14 minutes ago, MarcoSr said:

I have several thousand croc teeth but only a couple of mosasaur teeth so I don't know a lot about mosasaur teeth.  But I'm curious how so many TFF members can make an id on a very worn tooth where cutting edges and striations are not visible and the pictures are taken at an angle where you really can't see the shape of the base of the tooth clearly or the tooth cavity.  What diagnostic features are you seeing in this tooth  @Carl @The Jersey Devil @Jeffrey P @Bone guy @frankh8147 @FossilsAnonymous @Troodon @Fossildude19 @Rockwood    that clearly confirm a mosasaur id?

 

Marco Sr.

 

It's easy to make this ID with NJ teeth of this size. The Croc teeth pretty much have a maximum size of a bit over a half inch and the Mosasaur teeth get way larger. The juvenile Mosasaur teeth usually have an oval cross-section and are erect, while the Croc teeth usually have some bend and are normally more circular in cross-section. There's a chance that Deinosuchus can be found here, but so far there haven't been any definitive ones.

[The Jersey Devil]

8 minutes ago, Bone guy said:

I would think a crocodile tooth would have a round cross section.

 

This is true for most teeth, but the more posterior teeth are much more oval at the base.

 

11 minutes ago, Bone guy said:

You can see with this tooth the cross section is not perfectly round but a bit 'flattened' which is something's I've seen in other Mosasaur teeth. 

 

Some species of Mosasaur and also pterygoid teeth can have circular bases.

[Rockwood]

1 hour ago, MarcoSr said:

that clearly confirm a mosasaur id?

nothing

[JarrodB]

I'm 90% sure it's mosasaur but a pic of the inside of the tooth would help. 

[MarcoSr]

1 hour ago, The Jersey Devil said:

 

It's easy to make this ID with NJ teeth of this size. The Croc teeth pretty much have a maximum size of a bit over a half inch and the Mosasaur teeth get way larger. The juvenile Mosasaur teeth usually have an oval cross-section and are erect, while the Croc teeth usually have some bend and are normally more circular in cross-section. There's a chance that Deinosuchus can be found here, but so far there haven't been any definitive ones.

 

For those of us not familiar with the fauna at Ramanessin Brook in Monmouth County, NJ  your explanation is very helpful to understand that you used the size of the specimen in this post as a basis for your id.  Since I have so many croc teeth this size from other sites and that look like the specimen in this post I would not have thought to use size as a discriminator.  I have croc teeth with circular bases but have others with more oval bases (as you mention in another reply) depending on their jaw position so I don't find base shape a reliable single discriminator.

 

Marco Sr.

[historianmichael]

Thank you all so much for your help. I am glad you all could confirm my belief. As one of the above posters mentioned, my confusion stemmed from the potential for it being a crocodile tooth. I had recently looked at some of the online identification pages for teeth found in Big Brook and it raised some suspicions. As requested, here is also a photo of the base of the tooth. It is ovular. 

 

[goatinformationist]

Ovular and size clinches it

[Trevor]

5 hours ago, The Jersey Devil said:

 

It's easy to make this ID with NJ teeth of this size. The Croc teeth pretty much have a maximum size of a bit over a half inch and the Mosasaur teeth get way larger. The juvenile Mosasaur teeth usually have an oval cross-section and are erect, while the Croc teeth usually have some bend and are normally more circular in cross-section. There's a chance that Deinosuchus can be found here, but so far there haven't been any definitive ones.

 

http://collections.peabody.yale.edu/search/Record/YPM-VPPU-019472

 

http://collections.peabody.yale.edu/search/Record/YPM-VP-000274

[Rockwood]

Go YPM ! 

[The Jersey Devil]

58 minutes ago, Trevor said:

 

http://collections.peabody.yale.edu/search/Record/YPM-VPPU-019472

 

http://collections.peabody.yale.edu/search/Record/YPM-VP-000274

 

The Deinosuchus IDs (especially on the tooth) are most likely wrong. The tooth is likely Mosasaurine. It doesn't say where the bones came from, but they seem pretty fragmentary and I don't know how they narrowed that down to a genus.

[Rockwood]

Note for anyone new to this sort of discussion: Museums are not always assumed to be correct. Identifications are always subject to revision.