Carmel Church Day 3

No rain today, so we managed to get a lot of work done. We flipped and completed our first jacket, below:

That allowed us to get closer to the vertebral column and work on it in more detail, where we found…more vertebrae. There’s no indication that the column is ending. The red arrows below indicate new vertebrae from this whale, all found in the last 3 days:

One the other hand, one of the vertebrae found last year turns out to probably be from a different whale. The vertebra indicated below is a caudal (tail) vertebra, but it’s located adjacent to this whale’s thoracic (back) region. As a more posterior caudal, it’s probably also too large to be from the same whale.

Last fall we also found parts of both flippers, removing one of them. From the other, we removed the humerus (upper arm), and located the scapula (shoulder blade) and the radius (one of the forearm bones). Today we found the other forearm bone, the ulna. Below, “1” is the scapula, “2” is the radius, and “3” is the newly-discovered ulna (the humerus was originally sitting in about the position of the number “1”):

Late in the afternoon Christina Byrd happened to look behind her head and found a large fish vertebra, possibly from some type of billfish, sticking out of the St. Marys Formation (for those new to the blog, St. Marys’ fossils are very rare at Carmel Church):

We’re now trying to find a find a way to get through the vertebral column so we can make our next jacket. While it didn’t rain today, there’s now a chance of snow this Friday, so we’ll have to see how things progress.

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6 Responses to Carmel Church Day 3

  1. Doug says:

    I have always wondered: the concentration of bones seems to dense, how do you determine what belongs to one individual animal?

  2. Alton Dooley says:

    That can be tough, and we sometimes make mistakes. Obviously, if the parts belong to a single broken bone and they fit together, it’s a no-brainer. Multiple elements from one individual are a lot harder. Basically, we first look for articulation. If the bones aren’t articulated, we can sometimes rule out an association in various ways. If for example, there are three humeri, there have to be at least two individuals. Sometimes, there are large differences in size. There can be subtle differences in bone texture, amount of scavenging evidence, or preservation.

    So if we have two bones that are found in close proximity, have the same texture and preservation, are of consistent size and are complimentary elements (not repeated), then we might say they’re from the same individual. Even with that, I’ve missed a few. About 7-8 years ago we collected the a cranium and a rostrum, out of position relative to each other but only a few inches apart, and I assumed they went together even though there was no actual broken contact between them. One year later I collected a second rostrum from the same pit, and it turned out that it was the rostrum that went with the cranium; the other rostrum was a second individual.

  3. Boesse says:

    I hope it doesn’t snow on you guys. I’ve made a jacket in snowy weather once before, in 25 degree weather. That really isn’t fun. There’s a middle Miocene land mammal site near Bozeman that me and some other students did some ‘recreational’ fieldwork at, and often showed up even if it started to snow, and once during 10 degree weather. The worst part about it is that you more or less need bare hands for jacketing, and before warming them up, the plaster needs to dry. On that note… good luck!

    Thought I’d ask: has anyone ever (or is anyone planning) on investigating the taphonomy of the bonebed there at Carmel Church? My master’s thesis is on the range and distribution of taphonomic ‘styles’ (so to speak) across a mio-pliocene shelf (Purisima Fm), so I’m always interested to find out about marine bonebeds of any age.

  4. Doug says:

    Hey Boesse,
    What did you find at that land mammal locality? Only fossils i hear about (save for a couple exceptions) out of Montana is dinosaurs.

  5. Alton Dooley says:

    Why, Bobby, are you interested? 🙂 Nothing’s been published on the Carmel Church taphonomy, but we’ve been thinking about it a lot. Let’s just say it’s strange, with a lot of seemingly incompatible preservational styles. I’ve never seen anything like it, at least not at a single site.

    Now they’re calling for snow tonight. What fun!

    I’ll have the next post up sometime tonight. We’ve been working until it’s too dark to see, which makes us late getting back from dinner.

  6. Alton Dooley says:

    Well, it’s snowing, so we’re delayed this morning, so I’ll talk about taphonomy in a little more detail. Carmel Church includes isolated reworked bones, isolated non-reworked bones, associated but completely disarticulated elements, and partially articulated skeletons. Only one individual (an odontocete with about 5-6 bones preserved) seems to have desiccated before burial. There are a few oddities, like one specimen that consisted of about 10 associated ribs from both sides of the body and nothing else–not even vertebrae! And they were sitting draped over a skull from a baleen whale that was not the same individual!

    Nearly all the associated remains are from mysticetes. The articulated skeletons are usually belly-up. Four of the five best skeletons include skull material; three of them include forelimbs. All five of those specimens were oriented roughly east-west.

    There seems to be some variability in amount of scavenging, as well as in burrowing into the bones by invertebrates, but that hasn’t been quantified.

    One other curiosity; so far (current specimen pending), none of the articulated specimens include caudal vertebrae. We have found isolated caudals, but the numbers seem very small compared to the numbers of other column sections (again, this has not been quantified).

    Finally, remember that the entire site is less than 300 meters across.

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