Possible Predation?

[Down under fossil hunter]

Hello folks

I purchased a large block of matrix that was packed full of fossil bones a few years ago from a guy in Texas he had misidentified the bones as parts of a plesiosaur.

I asked a friend to help prep it out and was happy to find I had almost a complete set of upper and lower Xiphactinus jaws, one interesting anomaly that can be seen after prep is that there appears to be "crush/bite" mark on one of the jaws.

I don't know enough about the preservation to determine this myself but I am hoping that one of the Kansas/Texas locals will be able to share their opinion.

Could it be predation from a mosasaur or something else?

[Down under fossil hunter]

Here are a couple more pics

[RichW9090]

A picture of the opposite side would be helpful, as would a picture of the same side of the opposite jaw. It is really hard for a predator to make that kind of a mark on just one side of an animal - there is almost always an opposing trace.

Edited March 29, 2013 by RichW9090

[Boneman007]

I would say it could be predation. I would think that mosasaur or even another xiphactinus might be the culprit.

I have a number of Xiphactinus specimens and none of them have this type of thing on any of the jaws.

A full set of well preserved jaws is quite valuable as well! Nice aquisition!

I would love to see the rest of the specimen!

[Down under fossil hunter]

Hi Rich

The opposing segment of jaw was not included in the matrix (perhaps it ended up in some critters belly)

I did not post a pic of the reverse side of the jaw as there did not appear to be any visible sign of damage but here it is anyway, others might be able to see something I can't.

[Down under fossil hunter]

Hi Boneman

Here are some pics of the lower jaws.

There were a few more pieces in the matrix but they did not fit onto any of the larger jaw pieces so I have left them out.

Happy to hear that there could be some value to the specimen as I originally thought I paid too much for it (the prep cost more than the actual fossil).

I know that it is by no means a perfect example but do you have any idea what something like this might sell for?

[RichW9090]

I don't see anything on the reverse side, either. I suppose the opposing bite could have been on the other hemimandible.

Rich

[Down under fossil hunter]

If that is true (also my hypothesis) then it seems more likely that the bite occurred when the fish was complete (possibly still alive) rather than it being scavenged by something after its death.