Possible Pathologic Whale Vertebra Sharktooth Hill Bonebed

[siteseer]

This a whale cervical vertebra that was given to me 10-12 years ago. It is from the Middle Miocene Sharktooth Hill Bonebed (probably Bob Ernst's old "Whale Quarry" judging by the preservation). You will notice an unusual trough-like depression (perhaps 3-4mm at its deepest) in the bone surface. For years, I thought it was a bite mark though it seemed like a weird one. Then, a couple of years ago, I found this publication:

Thomas, H.W., Barnes, L.G., Klein, J.E, and S.A. McLeod. 2008.

Examples of paleopathologies in some fossil Cetacea from the North Pacific realm. In Wang, X. and L.G. Barnes (eds.).. Geology and Vertebrate Paleontology of Western and Southern North America. Contributions in Honor of David p. Whistler. Science Series. 41. Natural History Museum of Los Angeles County.

After looking at the various patholigies figured in that article, I think the depression is a pathology. It is too smooth to be a tool mark from the time it was dug out. A force strong enough to leave a mark like that would have shattered the bone of this preservation (rather fragile, ceramic-like quality) to some very noticeable degree.

Maybe someone else has seen or studied something similar?

[Scylla]

Could a power tool have made this mark? I'm thinking along the lines of a diamond saw or grinder. Also some of the bones from La Brea show wear marks that look like this from erosion of bone on bone grinding. Just a thought.

[Al Dente]

It looks like the work of a pholad clam to me. Here on the East Coast we find a lot of bone and even meg teeth with damage from boring clams. Here's a couple of links http://www.humboldt.edu/natmus/Case_indexes/Case_jpgs/MakeFossil.web/F-04.jpg

http://www.lakeneosho.org/Paleolist/69/index.html

[Scylla]

It looks like the work of a pholad clam to me. Here on the East Coast we find a lot of bone and even meg teeth with damage from boring clams. Here's a couple of links http://www.humboldt.edu/natmus/Case_indexes/Case_jpgs/MakeFossil.web/F-04.jpg

http://www.lakeneosho.org/Paleolist/69/index.html

Oh, yea that makes even more sense!

[siteseer]

Scylla,

It's unlikely it was prepped. I received this bone from a friend who found it and he didn't like doing any prep other than leaving something in a tub of water.

It's possible that something could have rubbed against it during compaction of the sediment but the depression has a weird smoothness to it.

Thanks for the comment.

Jess

Could a power tool have made this mark? I'm thinking along the lines of a diamond saw or grinder. Also some of the bones from La Brea show wear marks that look like this from erosion of bone on bone grinding. Just a thought.

[siteseer]

Al Dente,

Yes, it does look like that. It even has that slightly raised ridge in it. Molds of mollusk shells are found but uncommon in the bonebed. Most or all of the shell is gone.

Thanks, Al.

Jess

It looks like the work of a pholad clam to me. Here on the East Coast we find a lot of bone and even meg teeth with damage from boring clams. Here's a couple of links http://www.humboldt.edu/natmus/Case_indexes/Case_jpgs/MakeFossil.web/F-04.jpg

http://www.lakeneosho.org/Paleolist/69/index.html