Potential bite marks in turtle carapace

[Jasper12111]

 

Found this around the top of bed D at barton on sea. I am in contact with a couple experts, however told like to see if anyone has any more information to offer to shed a bit more light. Crocodiles from this specific area are extremely rare but not unheard of, and so far the general consensus is that it could be crocodile predatory marks. The top and middle indent are both around 5-6mm in diameter, and the larger one is around 16-17mm.

 

 

 

[digit]

What does the backside of the circular depression look like? I've seen a few predation marks on turtle shell pieces by crocodilians (alligators) from Florida. Features that help to support the probability that it is evidence of bite marks are additional depressions nearby (adjacent teeth) as well as a bulge opposite the "bite mark" where the shell material would have distorted away from the force of the bite (effectively the "exit wound").

 

The other possibility to consider are necrotic pits from infections. Infections often spread in circular shapes and pits left from these infections can quite often look like bit wounds. There would be no biting pressure so there would be no "exit wound" bulge on the opposite site--if anything it may show a circular depression as well.

 

Hope this helps. (Cause that is about the extent of my knowledge on this subject.)

 

 

Cheers.

 

-Ken

[Jasper12111]

there is a bulge the other side, however i think with that species of turtle it may be part of the ridge that would lead onto the spikes on the outside of the shell. the two marks on the side of the shell, however do seem to have pierced the carapace, just that the circular one happens to have occurred directly on the ridge. 

this certainly has been a large help, there isn't really anything for comparison from that area. there are also whales (basilosauridae) in the specific bed that the specimen is from, but extremely rare. could that be a possible explanation to the large spacings between the marks.

cheers 

jasper

[Rockwood]

Seem to fit the description of a turtle barnacle trace pretty well.  I would expect some cracking or lateral displacement if it were a bite mark,