New vertebra from Carmel Church

Our field jackets from Carmel Church have loads of bone in them, from a variety of different animals. This is true even when the jacket has been made to collect a single element like a skull. As an example, the jacket containing the skull of “Picasso” has so far produced remains from at least 19 different vertebrate species (plus “Picasso” itself). Most of these are sharks, bony fish, and whales, but some of the things are a little different.

The vertebra shown above was sitting under “Picasso’s” skull; since we opened the jacket from the bottom, we found this vertebra early in the preparation. As soon as it was uncovered I thought it looked a little odd for a whale, and as I looked at it more closely I saw some features that ruled out whales. One of the most prominent was a deep triangular fossa (a depression) at the base of the neural spine on the anterior margin, shown in the closeup below; this is an oblique view with low-angle lighting to make the fossa more visible:

We don’t have any other vertebrae like this in our collection, but when I attended the SeAVP meeting at the South Carolina State Museum last month (was that really only a month ago?) I was able to confirm that this vertebra is from a sirenian (a sea cow). The only recognized sirenian from the Calvert Formation is the dugongid Metaxytherium crataegense. We’ve already found several sirenian ribs at Carmel Church which are consistent with Metaxytherium, but this is the first sirenian vertebra we’ve recovered.

This entry was posted in Carmel Church Quarry, Carmel Church sirenians and pinnipeds, Chesapeake Group. Bookmark the permalink.

6 Responses to New vertebra from Carmel Church

  1. Nice!! Dugongidae was the first thing that came to my mind as soon as I saw the picture.
    There is another dugongid in the Calvert Fm., Nanosiren sp., from the Plum Point Marl Member (Domning & Aguilera, 2008). As the name implies, this species was small. Your specimen does seem to be in the size range for thoracics of M. crataegense.
    The triangular fossa are attachment sites for ligamentum flavum. I hope you find a skull next time!

  2. Alton Dooley says:

    Daryl Domning told me a few years ago that he suspected there was a second, smaller dugongid from the Calvert, but I didn’t know it had since been referred to Nanosiren.

    I would love to find a dugong skull, or even a few teeth! We’ll just have to keep looking; the next excavation is this fall.

  3. boesse says:

    That vert is so cute! It’s so tiny… is that normal size for Metaxytherium? I’m used to the larged Dusisiren and Hydrodamalis material here in California, I guess (which technically speaking, are giant dugongids anyway…).

  4. boesse says:

    er… meant to type “larger”

  5. Alton Dooley says:

    I haven’t compared it yet, but my impression is that it’s not especially small for Metaxytherium. I believe it’s missing its epiphyses, so it’s probably a juvenile.

  6. Brian Beatty says:

    Yes, Bobby, I think you’re warped by hydrodamalines…. Metaxytherium vertebrae are not terribly small compared to Nanosiren, which is about as small as a marine mammal could get without concerns for hypothermia. Nanosiren is odd in that respect, considering how it persisted maybe the longest as the Pliocene got cooler – maybe it found refuge in shallow, warmer waters? There is some nice Nanosiren material coming out of the Santa Fe River (FL) these days, with loads of cranial material. If one was found at Carmel Church, that would be amazing.

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