Hell Creek Dinosaur Tail Vertebrae id help

[jikohr]

Hi everyone,

 

Recently acquired some vertebrae from Hell Creek, I think the first one (1.4 x 1.1 x 1 inches) is a small Edmontosaurus caudal and the second (1,375 x 1 x .8 inches) is a Thescelosaurus Caudal. I'm still learning though so I wanted to confirm the id.

 

Any feedback is appreciated as always!

[hadrosauridae]

I'm curious to see what the experts say.  #1 does not look like any of the Ed. caudal vert shape I have seen so have.  #2 is definitely a distal caudal vert, but I cant give you any help with the species.

[jikohr]

2 minutes ago, hadrosauridae said:

I'm curious to see what the experts say.  #1 does not look like any of the Ed. caudal vert shape I have seen so have.  #2 is definitely a distal caudal vert, but I cant give you any help with the species.

They were both labeled as Thec when I got them but the morphology was so different I felt like I needed another opinion to be sure. They could very well both be thec or one could be pachy (I really hope one or both are pachy but I'm not holding my breath). Like I said I'm still learning Hell Creek, I've only just gotten what I consider to be okay with teeth, so take everything I say on that with a grain of salt.

[hadrosauridae]

7 minutes ago, jikohr said:

They were both labeled as Thec when I got them but the morphology was so different I felt like I needed another opinion to be sure. They could very well both be thec or one could be pachy (I really hope one or both are pachy but I'm not holding my breath). Like I said I'm still learning Hell Creek, I've only just gotten what I consider to be okay with teeth, so take everything I say on that with a grain of salt.

 

 

I stole this pic from @LordTrilobite on the forum

 

 

This is the shape I'm used to seeing.  See how much more compressed it is from your image?  The ends have a much thicker edge than yours, and the neural canal is much smaller in relation to the whole.  Now, maybe yours is a very distal vert and has different shape, and maybe the fact your is a partial is affecting how I see it.  Just wanted to show you the idea behind my thinking.

[jikohr]

11 minutes ago, hadrosauridae said:

 

 

I stole this pic from @LordTrilobite on the forum

 

 

This is the shape I'm used to seeing.  See how much more compressed it is from your image?  The ends have a much thicker edge than yours, and the neural canal is much smaller in relation to the whole.  Now, maybe yours is a very distal vert and has different shape, and maybe the fact your is a partial is affecting how I see it.  Just wanted to show you the idea behind my thinking.

Right I got ya.

The reason I thought it was Edmontosaurus is that the base of the process is much wider than what I was used to thinking as Thescelosaurus like the other one and Edmontosaurus seemed to fit. but yeah I figure it's either a distal Edmontosaurus or a Thescelosaurus/ Pachy from closer to the pelvis.

[Troodon]

The top one is Thescelosaurus but could also be Pachycephalosaurus.   The wrinkles on the edges of the centrum are the features that ID them.  The distal caudal is Thescelosaurus.

 

Do you have a locality where these were found?

[jpc]

10 minutes ago, Troodon said:

The top one is Thescelosaurus but could also be Pachycephalosaurus.   The wrinkles on the edges of the centrum are the features that ID them.  The distal caudal is Thescelosaurus.

 

Do you have a locality where these were found?

I agree about the bigger bone, but , troodon, can the tailbones be IDed beyond pachy/thesc?  

[Troodon]

29 minutes ago, jpc said:

I agree about the bigger bone, but , troodon, can the tailbones be IDed beyond pachy/thesc?  

I think so.  Lateral sides are very V shaped in thesc while Pachy appear flatish or curved .

 

Photos I took at BHI

This replica of Sandy

 

[jikohr]

37 minutes ago, Troodon said:

The top one is Thescelosaurus but could also be Pachycephalosaurus.   The wrinkles on the edges of the centrum are the features that ID them.  The distal caudal is Thescelosaurus.

 

Do you have a locality where these were found?

Powder River County

[Troodon]

Just now, jikohr said:

Powder River County

Perfect. Thanks

[jikohr]

10 minutes ago, Troodon said:

I think so.  Lateral sides are V shaped in thesc while Pachy appear flatish.

 

Photos I took at BHI

This replica of Sandy

 

Really? because (although it's a little hard to see in the picture, apologies) the sides of the large one are completely flat in the middle.

[Troodon]

Well the top row on pachy is about the location of yours.  Pretty clear its different.

 

Here is another image of more distal ones.

[jikohr]

Oh wow, what a comparison. Having those pics and the piece in front of me makes it pretty clear to be pachy which I am very okay with!

[Troodon]

The photos only reflect caudal vertebrae.

So let me reiterate your top one is a dorsal is either Pachy or Thesc. The morphology of those centrums is very similar.  Caudals, your bottom one is a Thesc. and you can see the difference in the photos.

 

[jikohr]

14 minutes ago, Troodon said:

The photos only reflect caudal vertebrae.

So let me reiterate your top one is a dorsal is either Pachy or Thesc. The morphology of those centrums is very similar.  Caudals, your bottom one is a Thesc. and you can see the difference in the photos.

 

so the top one isn't a caudal?

[jpc]

25 minutes ago, jikohr said:

so the top one isn't a caudal?

correct... it is a dorsal.  

[jikohr]

2 minutes ago, jpc said:

correct... it is a dorsal.  

Oh, okay got it. I'm glad I clarified! I'll put it down as a dorsal or either Pachy or Thec but can't be determined.

Thanks guys!