Mystery Pleistocene bones

Hey folks, I've been rather busy preparing for spring break (which I leave for in about 30ish hours), and I've actually gotten quite a bit accomplished - I finished preparing the whale cranium from the aforementioned post (there will be more follow up posts to that soon), and as of this afternoon, finished the second plaster/fiberglass cradle for the skull, which I will eventually be able to sink bolts through to keep the two halves together. Tommorrow I'll be attaching foam to the inside of the cradles, and then lugging the whole monstrosity to my (rather small) car. However, as this thing now weighs around 100 lbs or so, it is still only 1/3 of its original weight, so my car can do it.

Other than that, I submitted a manuscript this week (late monday night), about bite marks on some bones from the Purisima Formation; you'll hear more about it later on down the line.

Mystery marine fossils from the Pleistocene.

Anyway, as part of my mental preparation for spring break and looking at marine Pleistocene "rocks", here are some Middle Pleistocene fossils from a marine unit in California. I haven't been able to ID them, but they were originally ID'd by the collector as sea turtle claws. I'm naturally skeptical of that, but I'd like to see what you folks think, or if anyone can come up with something better (or, validate that ID).

Summer Adventures Part 5: new Herpetocetus cranium

Hey gang, I've finally returned from SVP and London, and finally beaten (nearly) this bad cold I've had (several of my office mates keep insinuating that I got swine flu; some other MSU students did - I was not so unlucky). So, in keeping with the attitude of my most recent posts, I will continue on with my summer adventures.

Earlier this summer I made a quiz type post, and never bothered following up on it (except in the comments). Well... for those of you too lazy to figure out what it was, now I'll show you.
I've shown the dorsal surface of the unprepared fossil adjacent to a photo of the well preserved cranium of Herpetocetus bramblei that I presented on at SVP in 200, with certain features lettered. A=zygomatic process of the squamosal; B= vertex; C = occipital condyles; D = exoccipital 'crest'. Herpetocetus, while exhibiting some decidedly 'primitive' features (primitive isn't politically correct, but given the nature of the cetacean cranium, its really convenient, and since this isn't peer reviewed, I don't care about 'PC'), also has a radically telescoped cranium. The radical telescoping isn't very obvious from the posterior cranium, though, and instead the primitive features are more salient. These include the extremely narrow and triangular supraoccipital shield, and the very anteriorly oriented zygomatic processes. Not terribly obvious from this specimen (because they are worn off), but very obvious on the H. bramblei cranium I have are vertically oriented, very well developed lambdoidal crests; these are typically laterally oriented in mysticetes, overhanging the temporal fossa. Now I'm just yapping; maybe I should really focus my chi into writing up that description...

In any event, the new fossil as exposed shows several diagnostic features of Herpetocetus (outlined above[ish]), and some features (such as the narrow supraoccipital) that are unique as far as Pliocene (and latest Miocene) mysticetes go. This last photo shows the slab (very, ver, very) slowly dissolving away in an acetic acid bath. I let it go while I was gone at SVP... and it didn't look any different when I got back. Acetic acid doesn't really degrade Purisima Formation nodules; it pretty much just softens them up to make airchisel prepping easier.

Stay tuned, folks - I still have tales to tell of fieldwork with Dick Hilton in Oregon, shark teeth lodged in sea otter skulls, and some other less interesting stuff I can't seem to remember at the moment.

Oh, and I got to be the 6,000th visitor to this blog - I rule.

Mystery fossil

Hello all,

Here's a couple bones I saw in a private collection over winter break, and these left the collector and myself stumped. I have no idea what on earth this thing is, but it looks mammalian.

Things to note: The concave part does look like an articulation, and the bones appear to be symmetrical. The larger of the two has some mud pellets cemented to it, so ignore those.

The part of the rock unit this is from is latest Miocene-Pliocene, and is generally devoid of sirenians. The usual suspects are pinnipeds and cetaceans.

I have seen a similar element at UCMP associated with an odontocete ulna, but nothing was said about the weird element.

Does this look obvious to anyone? I apologize for the colorful bedspread that served as my backdrop: