Hadrosaur Caudale vertebra from Utah, which species?

[JojoMozza]

Hi there,

I bought a hadrosaur caudal vertebra online a while ago and I was wondering what genus/species it is? It is from Southeastern Utah - I'm not sure which formation, the seller didn't say.

Just joined up and would appreciate any help or suggestions!

Thank you!

 

 

[LordTrilobite]

Without a more specific location it'll be very hard to put any name on this. Hadrosaurs are quite similar in their post cranial skeletons. When I'm at home I will dig some more in the literature. A rough position in the tail might be possible to discern. It looks like it's from around the end of the tail. Could you post pictures of the top and bottom?

 

There also still seems to be some matrix on the vert. Cleaning it some more might help with a possible ID.

 

Very nice piece though.

[Troodon]

Welcome to the forum

 

Agreed you're not going to be able to ID it beyond what you already have.  It's definitely a caudal, slight cleaning, where I marked in red, might expose if there is evidence of a lateral process with can tell us where it's located on the tail.  Hadrosaur material from Utah is extremely rare so it's an excellent pickup.  The Kaiparowits Formation, in southern Utah,  is one possibility where it came from since it contains hadrosaur Campanian in age that would fit your specimen. Other formations are included in the chart with possible species.  Lots of hadrosaurs around at the time.

 

 

 

[LordTrilobite]

Okay so I did some digging in the 2014 Hadrosaurs book. There's really good postcranial reference for both a basal Hadrosauroid and the very derived Hadrosaur Edmontosaurus. The basal hadrosauroid is from the Cenomanian of Texas. The Edmontosaurus reference is from the holotype and paratype of Edmontosaurus regalis.

 

Link to the Hadrosaur book:

http://www.iupress.indiana.edu/product_info.php?products_id=807281

 

 

Your vertebra looks a lot more similar to the Edmontosaurus reference as far as I can see. Your vertebra is quite similar to the mid and distal caudal vertebra. So I would suggest this is a mid to distal caudal vertebra. This is because the lateral processes seem to be present as Troodon mentioned. At the distal end of the tail the vertebrae don't have lateral processes. The neural arches get smaller and more slender towards the back of the tail as well. So while there are lateral processes present. The neural arch seems to be fairly slender.

 

Since it doesn't seem as close a match to the basal Hadrosauroid I think there is a larger possibility of this being a more derived Hadrosaur. Which would make the derived Hadrosaurs Gryposaurus or Parasaurolophus from the Kaiparowits Formation two obvious candidates. Totally jealous by the way.

 

There's some very good fossils of Gryposaurus. very complete ones too. So it might be possible to find some reference of that. The holotype of Parasaurolophus walkeri is missing it's tail. But there are some caudal vertebrae known from Parasaurolophus cyrtocristatus. There's some reference in Parasaurolophus cyrtocristatus, a Crested
Hadrosaurian Dinosaur from New Mexico from 1963. The caudals in there look similar but the pictures aren't good enough to make a very good comparison.

 

As far as I know Gryposaurus is a bit more common in general. While Parasaurolophus is a pretty rare Hadrosaur. So with the vertebra looking like a more derived Hadrosaur both of these are possible but not certain.

 

 

And of course it needs to be said again that the postcranial skeletons of Hadrosaurs are pretty similar in shape.

[JojoMozza]

Thank you so much LordTrilobite and Troodon for all the info! I've had a closer look at the vertebra and there definitely are lateral processes on both sides. Here are two more pictures of the top and bottom, I hope this helps.

 

[JojoMozza]

By the way, whilst trying to clean it further, I noticed a clump of red matrix next to the neural arch and tried to scrape it off, but couldn't, as it was extremely hard. It seems to be part of the bone somehow, so could it be preserved tissue of some kind? it is in the neural canal as well.

Thanks for your time!

Cheers!

[LordTrilobite]

Great photos!

 

That lump looks like some kidn of conglomoration of sediment. skin inprints are very rare so it's unlikely to be that. But this goes for all preparation. When in doubt, take a moment and figure it out before continueing. So only remove that lump if you're sure that it's just sediment and just continue cleaning the bone else where in the mean time. when cleaning also be careful of the broken areas like the neural spines, lateral processes and the front and back. Those areas will probably be more fragile. It's probbably a good idea to stabilise them a bit with some glue. With Paraloid B-72 for example. Be carefull not to glue the sediment as well though.

 

That photo from the under side also shows some interesting information. The bottom looks very blocky and wide. There are also 4 angle surfaces on the four corners. These angled surfaces are where the chervons of the tail attach. Vertebrae at the distal end of the tail don't have chevrons attached to them. So that's another indication that this caudal vertebra should be located towards the back, but not completely at the end of the tail.

[Troodon]

 I think the red material you are trying to scrape off may be the outer skin of the bone but it hard to say without holding it or it just may be concretion, I would leave it alone.   The material in the neural arch is just matrix that has hardened.   You can try removing it and opening up the arch but I would not do it without harding the arch with some consolidant.   That matrix may be providing support to the arch so you really need to be careful.

 

I mentioned how rare material studied from this locality.  Here is a image of the outcrops in Utah of that for formation, not much.

 

Preservation is not the best and here is an example of the most complete Paralophosaurus found in that formation.  You can see the vertebrae  

 

 

 

On a side  note these images come from a paper that discusses the changes in cranial ornamentation in these type of hadrosaurs.  Pretty interesting.

 

 

Access to paper +20 mb

 

https://peerj.com/articles/182/

[LordTrilobite]

It's worthy to note that that very complete Parasaurolophus is a juvenile specimen of less than a year old.

It's hard to tell before the vertebra is cleaned. But it looks like the neural arch is fused to the centrum. Which would mean you'd be looking at a more mature individual. The neural arch isn't fused to the centrum in juveniles.

[JojoMozza]

Thank you Troodon and LordTrilobite; you guys are like walking encyclopedias; I'm in awe of how much you know! I'll try to clean it up some more and see if that makes a difference, but I won't touch the red clump or the neural arch; it seems a bit fragile.

Thanks again for all your help!

Cheers!

[zekky]

I'm only aware of one piece of the Kaiprowitz in private hands, and it's owned by some High School in California. How different are Iguanodont verts from hadrosaur verts? Cedar Mountain perhaps?

[Troodon]

Anything is possible without a known locality but any cretaceous material from Utah is extremely rare.  To add to the complexity the preservation of the vert in question so not the best to identify 

 

Iguanodont caudal 

 

Outcrops of Cedar see purple are also pretty sparse.

 

[doushantuo]

hadrosaurBib.pdf

[Troodon]

Here is a hadrosaurid from the Cedar Mt Formation.  It certainty can be this we just cannot assess without a known locality 

Eolambia caroljonesa

 

Paper

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3471925/

[LordTrilobite]

When I was searching through the 2014 Hadrosaur book, I noticed that the more basal Hadrosauroids seemed to have caudal vertebrae that as a little fatter towards the top. The more derived Hadrosaur Edmontosaurus seemed to have a more slender top half and looked like a better fit with this vertebra. It's hard to tell. But I would lean more towards a more derived Hadrosaur for the time being.

[hxmendoza]

Are there any outcrops of the Kaiparowits Formation that are not within the boundaries of the Grand Staircase-Escalante National Monument that are legal to collect in?

 

At DMNS we're prepping a lot of Kaiparowits material from within the Monument. Would be interesting to find out if there are Kaiparowits outcrops outside the boundaries and on private land.

[jpc]

I agree that this probably a derived later Cretaceous hadrosaur.  But will disagree with the statement that chevrons are only at the base of the tail.  There is a specimen in Malta, MT... An articulated Bracylophosaurus? tail with about 66 verts... All the way to the tip, and it has chevrons almost to the end.  Hadrosaurs are actually quite common in the Kaipatowits, but as troodon suggests, rare to find for sale since all or almost all of it is on public land... BLM or national monument. 

I think you should be happy calling it a hadrosaur.