From the collections room (dromomerycid)

I’ve mentioned several times the fairly large number of land mammals found at Carmel Church, relative to the size of the exposure. One of the more unusual animals found there is a member of the family Dromomerycidae.

The Carmel Church dromomerycid material (which is the only specimen of this family known from Virginia) includes associated (!) hind limb material, including a partial left femur, both tibiae with the fused tips of the fibulae, and part of the fused 3rd and 4th metatarsals:

Dromomerycids are an interesting group of artiodactyls, found in the Miocene and Pliocene of North America. They were probably deer-like in their habits and general appearance, although they had true horns rather than antlers. Most had a horn growing above each eye, and some had a third horn growing from the back of the skull (as in this example of Procranioceras from AMNH):

I haven’t been able to identify the Carmel Church remains to genus (and it may not be possible to do so), but the overall shape and details of the anatomy are consistent with other dromomerycids, except for size. Here’s the tibia compared to Procranioceras skinneri (AMNH specimen):

And the other tibia next to Pediomeryx (FLMNH specimen):

Clearly the Carmel Church animal is quite a bit smaller than these. We could be dealing with a juvenile, although I suspect from the general appearance of the bone that’s not the case. There are smaller dromomerycids known from this time period, so the Carmel Church animal could be one of these.

And here’s one other neat feature of these bones – they have a number of bite marks, likely caused by sharks scavenging the carcass after it floated out to sea:

These bones were described in Jeffersoniana 18, which is now available online.

Dooley, Alton C. Jr., 2007. Barstovian (middle Miocene) Land Mammals from the Carmel Church Quarry, Caroline County, Virginia. Jeffersoniana 18, 17 pp.
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10 Responses to From the collections room (dromomerycid)

  1. Doug says:

    neato, associated stuff! Did you ever identify those mammal teeth that you found inside or next the jaws of a whale?

  2. Brian Beatty says:

    I’m glad to see these guys here, thanks Butch.
    It should be also noted that dromomerycids are also considered to be part of the Family Palaeomerycidae, which include a number of Eurasian forms and does some good in relating North American ruminants that made it here in the Oligocene to critters in Eurasia. North American ruminant origins are a problem that needs to be solved, and these guys might be part of the key to it alll.
    One of the more primitive groups of them are the subfamily Aletomerycinae, including Aletomeryx and Sinclairomeryx. I just described a new genus from the Hemingfordian of FL (JVP in press), so I’ll try to put something online when it’s out.
    Cheers,
    Brian

  3. Alton Dooley says:

    Doug, I’ll be doing something on the camel teeth from Carmel Church soon. I actually just had them up at the Smithsonian a couple of weeks ago, attempting an identification.

    Brian, was that the critter you talked about at the first SEAVP meeting?

  4. Jeff Sparks says:

    Could it be Kryptoceras?

  5. Alton Dooley says:

    I’m not familiar with Kryptoceras (or am I missing something?). The size is about right for Bouromeryx, but it actually looks more like Procranioceras, except for the size.

  6. Doug says:

    Camel? So you think they are camel? I remember you said that was a big deal.

    If you follow the link in my name, you’ll see a partial skull of Dromomeryx from my trip to Oregon this summer. Also, Alton, i think i might have some Bauromeryx pcitures you could look at. Lastly, i highly doubt it’s Kryptoceras. You say it’s a dromomerycid and that it’s smaller in size than the compared material. So that should immediately rule out Kryptoceras, seeing as it’s the largest of the Protoceratids.

  7. Alton Dooley says:

    Ahh, Kyptoceras, not Kryptoceras. Couldn’t figure out what y’all meant (guess it should have been obvious…).

    As I recall (don’t have my notes in front of me), I compared these to Bouromeryx, Aletomeryx, Sinclairomeryx, Cranioceras, Procranioceras, and Pediomeryx (all at AMNH, except Pediomeryx at FLMNH). None were perfect matches, but it’s really close to Cranioceras and Procranioceras, except for size. The Cranioceras specimens I looked at are smaller than Procranioceras, but still bigger than the Carmel Church specimen.

    I also haven’t compared it to Brian’s little Florida guy, which is a bit older (Hemingfordian, rather than late Barstovian). It’s quite possible that the dromomerycids from the midwest aren’t the same taxa as those from the east coast, which could be why I struggled getting a match.

    The teeth we got from Carmel Church last year were indeed camel; I think 8 teeth from one individual. It’s the only camel known from the Calvert Formation, as far as I know (I still have to confirm that, though).

  8. Doug says:

    Hey Alton, i was wondering if i could get your opinion on something. I have gotten in a discussion over at Dinosaur tracking about skeletal mounts: http://blogs.smithsonianmag.com/dinosaur/2009/08/20/cast-your-vote-for-the-1-dinosaur-museum/
    One commenter feels that dinosaur mounts shouldn’t be updated and reposed because he feels the old ones are works of art. I then laid out the many reasons why mounts are updated. He conceded that they were good points, but that many “new and improved”(quotations his) mounts contain “hideous inaccuracies”. He cited the T. rex mount at the American Museum as an example, with it’s “widely separated coracoids, hyperextended left knee, misaligned forelimbs, and non-artometatarsalian feet”. He finished by saying “If you are going to do it, it really wouldn’t kill you to do it right.” (like it was intentional). I haven’t been to AMNH, but looking threw a great many photographs, i didn’t see anything wrong (but then, dinosaurs aren’t my area of expertise, only an interest). They sound rather trivial. I mean, is the average museum goer going to notice such things? Do these small inaccuracies really destroy the scientific accuracy and integrety of the mount? What do you think?

  9. Alton Dooley says:

    Well, I haven’t been following the discussion over there, but I’ll say to start that I’m not crazy about mounting real skeletons at all; I prefer casts. Few things are more of a pain to a researcher than to need to examine a specimen in detail and find it unavailable because it’s on exhibit.

    In mounting any skeleton, whether it’s a cast or the real thing, there will always have to be compromises, because of missing elements, soft tissue constraints on motion, uncertain positional relationships, and bone deformation. How do you ever know for certain exactly where the scapula attaches to the ribcage? Any mount is a hypothesis to a certain extent.

    I have no problem with remounting skeletons to more closely adhere to modern understanding of these animals. While there is some merit in the view that the old mounts themselves have some artistic and historical value, I think that’s outweighed by the educational value of a mount that is “more correct”, particularly if a real (and presumably rare) skeleton is involved. Even so, I love the Crystal Palace iguanodonts!

    The museum at the University of Nebraska addressed this with their Allosaurus skeleton and life-sized model, which are in old-style mounts and which they apparently don’t have funds to remount. They made a rather detailed exhibit describing why we now think the mount is incorrect. If they ever have the funds available, I hope they remount the skeleton, but keep the model in its original form.

  10. Doug says:

    Yeah. Whether ti’s the real fossils or not, i feel that the missing bits should be a different color. That way, you have a whole skeleton but they can still see what was found and what’s been reconstructed.

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