Dino Dad 81 Posted July 18, 2021 Share Posted July 18, 2021 (edited) Thanks for taking the time to check this out. The vert is ID'ed as Dromaeosaurus from Hell Creek Fm, Powder River County. I've been having a frustrating time trying to make better sense of this, since, as for as I know, there have been no Dromaeosaurus IDs in HC. Are any of you able to shed light on the likelihood of it being dromaeosaurid and anything beyond that? The measurements are 1.875" long * 1" wide * 1.625" tall. (I have a vert centrum ID'ed as Dromaeosaurus from a Judith River Fm and it's only about 0.8" * 0.4*0.5. Position may well explain the huge size difference, but I'm not sure about that either.) Any input you have would be greatly appreciated. Edited July 18, 2021 by Dino Dad 81 Link to comment Share on other sites More sharing options...
Thomas.Dodson Posted July 18, 2021 Share Posted July 18, 2021 I can't help with the ID (@Troodon) but apparently there are dromaeosaurids in the Hell Creek from faunal lists that Troodon has listed as reference before, both described and undescribed. Link to comment Share on other sites More sharing options...
Troodon Posted July 18, 2021 Share Posted July 18, 2021 Very little is published on smaller theropods from the Hell Creek other so its best to try to compare against those in other faunas. Here is a dorsal from a Dromaeosaurid from Alberta and you can see it compares somewhat against yours and both have the same general morphology with a large pleurocoel. However there are other theropod in that fauna like Richardoestesia and Troodon that cannot be discounted. So your vertebra is a Cervical and a good chance its from a Dromaeosaurid.. Beyond that we have nothing published on the vertebrae of the two Dromaeosaurids which exist in the HC, Acheroraptor and Dakotaraptor. Has far as size no idea how big cervicals get on these two Dromaeosaurids. Illustration: Guide to Common Fossils from the Cretaceous of Alberta. 5 Link to comment Share on other sites More sharing options...
Dino Dad 81 Posted July 19, 2021 Author Share Posted July 19, 2021 Very grateful for this information @Troodon. I tried to dig into size to see if it could narrow things down any further and saw that acheroraptor is only known for the maxilla and dentary find. Dakotaraptor doesn't seem to have any cervical vertebra described. Do you think it's more sound to further investigate the size factor by comparing the dimensions on this cervical vertebra to: (a) non-cervical vertebra from dakotaraptor, to see if this one can/can't be from an animal that size (b) cervical vertebra from other dromaeosaurids of varying sizes and extrapolating to see if this one seems to fall in one direction or the other (e.g., looking at dromaeosaurus/velociraptor vs deinonychus) Thanks again! Link to comment Share on other sites More sharing options...
Troodon Posted July 19, 2021 Share Posted July 19, 2021 If you are looking to confirm its a Dromaeosaurid that works. However if you are looking to ID it to a DR thats a waste of time since we have no specimens to compare against. Link to comment Share on other sites More sharing options...
Dino Dad 81 Posted July 19, 2021 Author Share Posted July 19, 2021 You know me too well @Troodon Thanks again Link to comment Share on other sites More sharing options...
jpc Posted July 19, 2021 Share Posted July 19, 2021 Nice find. I am curious as the how you measured it down to the nearest thousanthof an inch. : ) Link to comment Share on other sites More sharing options...
Dino Dad 81 Posted August 7, 2021 Author Share Posted August 7, 2021 @Troodon (or anyone else who can help), this is thought to be from a HC dromaeosaurid. I'm trying to dig deeper and came across the Deinonychus 3rd metarcarpal. What do you think? Can this or anything else make a reasonable dromaeosaurid case (and I'll dig no deeper than that IMG_2818.mov (video attached) Link to comment Share on other sites More sharing options...
Troodon Posted August 7, 2021 Share Posted August 7, 2021 Not sure what you are trying to ask with that illustration in relation to that vertebra Link to comment Share on other sites More sharing options...
Dino Dad 81 Posted August 7, 2021 Author Share Posted August 7, 2021 Sorry @Troodon, I'd pivoted to another alleged HC dromie specimen--a metacarpal or metatarpal. The video of it was too camouflaged in. Re-uploading IMG_2818.mov Link to comment Share on other sites More sharing options...
Troodon Posted August 7, 2021 Share Posted August 7, 2021 Photos of all sides please, videos are not good to ID specimens. I also do not like uploading video's. Link to comment Share on other sites More sharing options...
Dino Dad 81 Posted August 7, 2021 Author Share Posted August 7, 2021 Sorry @Troodon, here they are: The vert and bone I've posted here are some of my first real steps outside of teeth. I'm really surprised by how much I'm enjoying these two. Reminds me of something you wrote in a collection thread about you generally preferring to collect claws, verts, etc. relative to collecting teeth. I feel ya. Link to comment Share on other sites More sharing options...
Troodon Posted August 7, 2021 Share Posted August 7, 2021 Its a metatarsal (foot) missing its proximal end. Dont believe its a Dromaeosaurid just the wrong morphology. What size is it? Link to comment Share on other sites More sharing options...
Dino Dad 81 Posted August 8, 2021 Author Share Posted August 8, 2021 (edited) Thanks @Troodon. The seller listed it as a metatarsal, but, in correspondence it, indicated he wasn't sure of whether it was a metatarsal or metacarpal--just that it was dromaeosaurid. But I have little personal familiarity with his expertise--I just know he's an established source for these things. Based on the Ostrom paper I got the deinonychus manus picture from, the only bone in deinonychus that seemed like a possible analog was metacarpal III. But, if it's not even dromaeosaurid, than my deinonychus comparison goes out the window. Please let me know if you were looking for different measurements. Edited August 8, 2021 by Dino Dad 81 Link to comment Share on other sites More sharing options...
Troodon Posted August 8, 2021 Share Posted August 8, 2021 Interesting so your seller could not determine a simple fact that it was a metatarsal versus a metacarpal yet he was able to say it was a Dromaeosaurid, a definite red flag that everyone followup on like you did.. He just based it on size. Not much is published from the HC on these metatarsal bones to compare against. My best call is that its a Caenagnathidae when I compare it to those in my collection but its a guess since there are other small theropods it could be. Could also be an ornithomimid. 1 Link to comment Share on other sites More sharing options...
Dino Dad 81 Posted August 8, 2021 Author Share Posted August 8, 2021 Incredible resemblance! You're the man. Thanks so much. Link to comment Share on other sites More sharing options...
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