Homepage › Forums › What Is It? › Chevron bones known in Oreodon tails?
Tagged: Merycoidodon Tail White River
- This topic has 7 replies, 3 voices, and was last updated 6 years, 7 months ago by Bruce MacFadden.
September 25, 2016 at 6:35 pm #12698
Whilst preparing a Merycoidodon culbertsoni that I found in 2012 in the Lusk/Wyoming area I discovered several small bones between and seemingly underneath the caudal vertebrae all along the tail. The bones in question appear between 5 different caudal vertebrae and decrease in size. Here photos of the 3rd and 5th bone. The 5th and smallest bone is situated between the 10th and 11th caudal vertebrae. The specimen is from Whitneyian layers. I could find no evidence of such bones in the literature available to me. I would be interested to know wether such bones (chevron bones?) are known from Merycoidodontinae. Thanks a lot. Martin Dammann
Attachments:You must be logged in to view attached files.October 6, 2016 at 10:49 am #12985Eleanor GardnerModerator
Hi, @martin-dammann! Interesting find! Although I’ve done field work in the Lusk, WY, area, I don’t have much knowledge of oreodont skeletal morphology. Perhaps @bmacfadden, @smoran, or @sue-hirschfeld could help you out. What do you all think?October 12, 2016 at 4:02 pm #13659
The skeleton is beautiful and the chevron bones are interesting. I am not aware about reports of these. Let me do some hunting and looking at references. I will let you know if I find something. Is it OK with you if I cut and paste your photo(s) and send them to someone who is a better anatomist than I am?October 13, 2016 at 8:39 am #13686
I have now consulted textbook of veterinary anatomy (Sisson and Grossman) and read the sections about skeletal osteology. There are no reports of accessory chevron bones in the caudal vertebral series. Are you sure that the extra bone in question associates with the tail vertebrae, or could it be from another source, like a fragment from elsewhere in the fossil?October 13, 2016 at 8:31 pm #13885
Hello Mr. MacFadden. Thank you very much for this information.
The fossil is prepared and visible from above. There are some foot bones of the hind legs that have fallen off and drifted a bit, but they are in higher niveaus of the rock. At this time the tail must allready have been fully covered. All other bones are in the original position. I have found no remains whatsoever of other animals associated in this rock.
All this makes it unlikely to me that they are drifted bones or fragments from other parts, yet of course if there were chevron bones at any joint some must have drifted or ly underneath the vertebrae.
I add a photo of the entire tail with the marked bones and details of the small bones 1, 2 and 4. Bone 3 and 5 are allready depicted.
Please do show the photos to a colleague if helpfull.
Attachments:You must be logged in to view attached files.October 13, 2016 at 9:14 pm #13890
This still baffles me. I’ll keep looking. Your photos are very clear and they are very helpful. If I find something out, I will let you know.October 15, 2016 at 6:37 pm #13903
I would be very gratefull on anything you can find out. I realized I can fineprep some parts a little bit more.October 15, 2016 at 7:59 pm #13904
Martin–Yes, I will keep trying. Bruce
You must be logged in to reply to this topic.