I need some help with the reconstruction of KUVP 40002 (holotype of Trinacromerium bonneri). I'm working on the caudal series now, and while most of them seem to be there (except for the tip) I have no chevrons Williston in his description of KUVP 1300 (T. Osborni) mentions that it had haemal arches composed of 2 parts, pointing outward and posterior. I checked the mount of KUVP 1300 last week, and if you looked at the centra from head on, they looked a bit like stars (neural spine, transverse processes, and haemal arches forming 5 points).

However on our cast of Elasmosaurus, it has traditional "Y" shaped chevrons. The literature is vague on the caudal regoins, with most focusing primarily on the skull and girdles. Did Williston get it correct on the T. osborni mount in 1903, or are there any other references I should check that has detailed caudal information.

Nevermind about this. It appears that the original Williston description was correct. I will post pics in 2 weeks when my camera has been repaired. Evidently it wasn't designed for 2 week stints in the badlands.

Hi, Was there another change? Trinacromerum bonneri was shown to be Dolichorhynchops osborni recently . Have they changed it back again?
"Trinacromerum bonneri" Adams 1997, was described in a paper written, but not published, before Ken Carpenter's 1996 revision of Trinacromerum and Dolichorhynchops. Carpenter attributes the skull in the Kansas Museum of Natural History (KUMNH 40001) that Adams used as part of type specimen of T. bonneri to Dolichorhynchops osborni--Trinacromerum bonneri Adams appears to be a junior synonym of Dolichorhynchops osborni Williston as defined by Carpenter (1996). Plesiosauroidea Polycotylidae Late Cretaceous (Cenomanian- Turonian) NA.
What reference is there for this?
Thanks very much, Barry (Teoslola)

I think a lot of the issues here arise in that Adams' description (1977 masters thesis) was done on a half prepared on one side critter. Just today we have finished casting all the original material on the holotype (KUNHM/KUVP 40002) and from what I've seen, the vertebral counts are all wrong. The illustration that Adams published in 1997 and republished in 1997 of the cervical series is wrong, it is missing a whole vertebra. The dorsal count is also different than published, as is the caudal count.

Also a little clarification. The skull, KUVP 400001, is the paratype. The holotype does have an occipital condyle and some frags, but the rest of it is missing.

I answered most of my questions when Ken Carpenter came and visited about a month ago. The haemal arches are not Y shaped chevrons, bit splints of bone that attach to caudal facets and angle downward and outward. more outward in the proximal ones, transitioning to more downward in the distal ones.

KUVP 40001 and 40002 are undergoing a new description (Dave Burnham is working on this) and I think now that the buggers are finally fully prepared, we'll be able to seperate them from D. osborni. The different pre-caudal counts, different cervical/dorsal breakdowns, and most importantly, the limb proportions (front paddles are each about 15cm longer than rears) are enough to keep it D. bonneri, if not a new genus all together.

Thanks,
So why is it D. bonneri rather than T. bonneri as she named it. Is D. bonneri then more related to D. osborni?
They did find all the missing Trinacromerum holotype material from Cragin so Trinacromerum is a valid genus. Our material is all T. bentonianum and was gone over by Elizabeth Nicholls in 1996-7 and later on by photo as well. She is the one who gave us the correct points for making sure what we had. I had done that on my own first and she backed me up...without me knowing she already had named the material.
I would have published by now but a bout of heart attack, strokes, and triple bypass surgery did that in on a timely basis. I will be publishing in the near future as we have so much material is would be a crime not to….from near fetal to fully adult Trinies, elasmosaurids, many fish including numerous shark, and some float and drifted in dino material, and much more.
We still have a couple mystery bones that we need to finalize on as well.
Barry

Well, not D. bonneri per se. It's close to D. osborni, though the proportions when all is said and done are going to be strange. Ballpark figures from my pre-restored vertebrae times is about 14 foot length snout to tail. Skull as long as neck, dorsal series as long as front flippers. 12 foot front paddle span (with little space between coracoids) about 10 1/2 feet rear flipperspan. body is starting to look chunky, but those massive forelimbs are definitely the hallmark of something different, rather than just sexual dimorphism. I goofed on the vert count, there are the same number of dorsals as in Adams' publication. The only thing to have changed is the cervical count.

Your site sounds a lot like our "TMBB" site. Upper Judith River fm, has at least 3-4 adult plesiosaurs, 2-3 juveniles (humerii 4-5 inches long) but it also has shark (squalicorax-type) enchodus, sawfish, 2 types of mosasaur (cf tylosaurus and clidastes) soft shelled turtle, and 2 types of dinosaur (oviraptorid and hadrosaur). Don't you love bonebeds?

Project update:

Skull is done, neck is done, tail is done, flippers are done, Dorsal column will be done this week. All that is left are the (TRICKY) girdles, ribs, and the gastralia. If anyone has any hints on how to do the gastralia, please share. Photoraphs on the web are proving to be not very useful now.

UPDATE:

Prototype is nearly complete. Debut will be at Tucson this year, with an unveiling at the RMDRC in late Feb. Hopefully 5-6 experts will be there, so9 it will be more like an impromptu plesiosaur symposium. I'll keep you updated on the speakers and date, but for now, here's pics of the skeleton before ribs and gastralia (and illia...)

Polycotylus (T. bonneri) Vs. Xiphactinus!


Truly big animal, 12 foot front flipperspan


Another front view


Pectoral girdle still needs tweaking, but all in all, from a super smashed flat fossil from the pierre shale (see posts in the prep section for pictures of the gypsum horror) I'd say it came out pretty well!