Eocene shark tooth identiciation

[TheFloridaHerper]

Hi all, I found this while diving a north FL river, assuming Eocene in age from the limestone of the river. Was mixed amongst Pleistocene vertebrate fossils. Any ideas? Thinking maybe lower Hemipristis curvatus but not sure. 

[hemipristis]

Nice tooth!

[shark57]

I don't know what it is, but it definitely is not Hemipristis.

[NoahH]

I don’t know what it is, but that is a really cool tooth!

[Anomotodon]

This is a very interesting tooth. Definitely an anterior tooth from a lamniform, but which one… If it is Eocene, then a juvenile (symphyseal position?) Otodus obliquus is I think a likely option. Contemporary lamnids with similar tooth morphologies like Isurolamna barely had any cusplets on anterior teeth. Tethylamna/Brachycarcharias/Serratolamna/Cretolamna twiggsensis anteriors were very similar to your tooth, but had a defined nutrient groove on the root which your tooth lacks. Of course it is also possible that the groove is just worn on your tooth, in which case this species might be a better fit.

 

But is it possible it came from Cretaceous deposits? My first thought was Archaeolamna kopingensis which can have such laterally compressed anterior teeth, a large protuberance, no nutrient groove and a somewhat sigmoid crown like this but is restricted to the Cretaceous. What other shark teeth do you find at this site?

 

EDIT: is this from Ocala limestone? That is late Eocene which rules out O. obliquus, so T. twiggsensis is my guess then. 

Edited November 29, 2024 by Anomotodon

[Jared C]

On 11/29/2024 at 11:23 AM, Anomotodon said:

But is it possible it came from Cretaceous deposits? My first thought was Archaeolamna kopingensis which can have such laterally compressed anterior teeth, a large protuberance, no nutrient groove and a somewhat sigmoid crown like this but is restricted to the Cretaceous. What other shark teeth do you find at this site?

 

 

Eocene deposits are the oldest deposits in Florida