Need Id On 2 Strange Marine Mammal Bones.

[Kkoz]

Hi,

I found these 2 strange bones in a small miocene outcrop in southern california. I also found about 10 misc. shark teeth and abundant bone fragments. These bones are about 2cm long and 1.4 cm wide. What are they?

Thanks.

[Auspex]

Possibly cranial; inner ear bones?

[Kkoz]

That's what I was thinking. Thanks auspex.

[Auspex]

Our member Boesse can probably elaborate; it is his field of study.

I have messaged him.

[Al Dente]

The one on the right looks like part of a bird humerus.

[Auspex]

The one on the right looks like part of a bird humerus.

Huh, I see what you are saying. It's well pneumatized, too...

[Boesse]

They both appear to be proximal humeri of the flightless auk Mancalla. Because the muscle attachment scar extends into the pneumatic fossa and is formed as a raised ridge at least the specimen on the right in the right hand photo appears to represent Mancalla lucasi (the species formerly known as M. diegensis).

M. lucasi is widely reported from the Pliocene and Pleistocene of California, including the San Diego, Purisima, and Moonstone Beach formations:

http://www.pensoft.net/inc/journals/download.php?fileId=2076&fileTable=J_GALLEYS.

http://www.palarch.nl/2011/09/robert-w-boessenecker-2011-a-new-marine-vertebrate-assemblage-from-the-late-neogene-purisima-formation-in-central-california-part-i-fossil-sharks-bony-fish-birds-and-implications-for-the-age-o/

[Auspex]

Thanks, Bobby!

Good finds, Kkoz!

[Kkoz]

Thanks for the input everyone!

[jpc]

a day late and a dollar short, but I see bird humerus in the right specimen, second photo.