Tortoise or sea turtle peripheral?

[fossil_lover_2277]

Hi all, I found this turtle peripheral in eastern North Carolina. I believe it is from Cretaceous Black Creek group sediments, but Pliocene Yorktown formation is also possible (both are marine). A person I showed it to said it was a Hesperotestudo (tortoise) peripheral, not sea turtle, so thus terrestrial (I guess it might be terrestrial Pleistocene, but that would be unlikely, I don’t find much of any Pleistocene material where the shell was found). However, it actually looks similar to a peripheral I have from a known fossil sea turtle. 
 

Is this peripheral sea turtle or tortoise?

[Lorne Ledger]

I agree with Hesperotestudo.  Looks like the right size for a chunk of tortoise shell.  Also Pleistocene.  Pleistocene material can turn up anywhere btw.

[fossil_lover_2277]

44 minutes ago, Lorne Ledger said:

I agree with Hesperotestudo.  Looks like the right size for a chunk of tortoise shell.  Also Pleistocene.  Pleistocene material can turn up anywhere btw.

Thanks, learned a lot here.

[Al Dente]

Cretaceous sea turtle. These pieces are very common at some Black Creek Group lag deposits. Here are a couple that I kept.

 

 

[fossil_lover_2277]

42 minutes ago, Al Dente said:

Cretaceous sea turtle. These pieces are very common at some Black Creek Group lag deposits. Here are a couple that I kept.

 

 

Thank you. I thought this was the case, they looked similar to another sea turtle peripheral I had. But I don’t know enough about turtles to be sure myself. Multiple said tortoise (which I know nothing on regarding anatomy), so I assumed I might be wrong.

 

Nice pieces btw. Most of them I find aren’t that large or intact, just small fragments. 

Edited December 26, 2021 by fossil_lover_2277

[Al Dente]

7 minutes ago, fossil_lover_2277 said:

Most of them I find aren’t that large or intact, just small fragments. 

I find quite a few large pieces but they are so brittle they almost never make it home in one piece. 

[fossil_lover_2277]

4 hours ago, Al Dente said:

I find quite a few large pieces but they are so brittle they almost never make it home in one piece. 

Any idea on what species or genus they might come from? Based on comparison to the peripheral and other carapace pieces from a moderately-sized Oligocene sea turtle I have. These Cretaceous turtles must have been huge. I’ve looked up online some and tried comparing to known species from New Jersey, but couldn’t find much similar to mine and the pics you sent.

[Al Dente]

1 hour ago, fossil_lover_2277 said:

Any idea on what species or genus they might come from?

I don’t know. There isn’t much published on NC Cretaceous turtles.

[fossil_lover_2277]

56 minutes ago, Al Dente said:

I don’t know. There isn’t much published on NC Cretaceous turtles.

Thank you

[Plax]

I guess that having a rule of thumb to separate sea turtles from side necks like Bothremys is a must for such turtle bone. I'd say that most of the Tarheel Formation large turtle bone is Bothremys and younger formations sea turtles tend to dominate. Probably more an environmental thing as opposed to the age.

[Al Dente]

3 hours ago, Plax said:

I guess that having a rule of thumb to separate sea turtles from side necks like Bothremys is a must for such turtle bone. I'd say that most of the Tarheel Formation large turtle bone is Bothremys and younger formations sea turtles tend to dominate. Probably more an environmental thing as opposed to the age.

Bothremys didn’t enter my mind but now that I looked up some images, I think Bothremys is a good candidate for these fossils.

[Plax]

1 hour ago, Al Dente said:

Bothremys didn’t enter my mind but now that I looked up some images, I think Bothremys is a good candidate for these fossils.

Was hoping you had a rule of thumb Al! I can't tell them apart unless they are sea turtles with distinctive ornamentation on their bones. a couple of Peedee turtles come to mind.

[fossil_lover_2277]

7 hours ago, Al Dente said:

Bothremys didn’t enter my mind but now that I looked up some images, I think Bothremys is a good candidate for these fossils.

 

11 hours ago, Plax said:

I guess that having a rule of thumb to separate sea turtles from side necks like Bothremys is a must for such turtle bone. I'd say that most of the Tarheel Formation large turtle bone is Bothremys and younger formations sea turtles tend to dominate. Probably more an environmental thing as opposed to the age.

Thanks for the input, wouldn’t have guessed a side-necked turtle at all on my own.

[Plax]

Only probably a Bothremys and by default at that. It is the most common turtle find in the Tarheel and Bladen. At some sites it has been jokingly called "pavingstonia" for its abundance. Am no turtle expert.