Tyrannosaurus rex vertebral process fragment?

[Mochaccino]

Hello,

 

I recently bought this tiny bone fragment, a supposed piece of Tyrannosaurus rex vertebral process, from the Hell Creek Formation of Harding County, South Dakota of USA. I know nothing about ID'ing dino bones or bones in general. The seller's rationale for the ID was that the porous honeycomb structure is diagnostic of large theropods, with the only one in this formation being T. rex. Does the ID seem correct? Is this T. rex proper or is that impossible to determine?

 

The piece is 3 cm long. I've propped it up to better visualize the large pores inside the fragment. Also, I'm wondering what the black, chocolate-looking substance filling many of the pores is. Is that just what the matrix looks like?

 

 

Thanks,

 

 

Edited June 16, 2022 by Mochaccino

[Rockwood]

Seems possible, but conclusive may be a step too far. @Troodon

[Troodon]

Interesting.  Honecomb structures are typical of tyrannosaurids like the image of a Trex vert shown below.  Never examined or seen a broken spine but yours looks like the expected honeycomb structure but its not  hollow and filled in by a black material.  So not sure what you have and cannot be certain its from a Tyrannosaurid. .   The fragment is small so if its a Tyrannosaurid it will be difficult to determine if its Trex or Nanotyrannus.   Hopefully someone has more info on this.

 

[Mochaccino]

21 hours ago, Rockwood said:

Seems possible, but conclusive may be a step too far. @Troodon

 

12 hours ago, Troodon said:

Interesting.  Honecomb structures are typical of tyrannosaurids like the image of a Trex vert shown below.  Never examined or seen a broken spine but yours looks like the expected honeycomb structure but its not  hollow and filled in by a black material.  So not sure what you have and cannot be certain its from a Tyrannosaurid. .   The fragment is small so if its a Tyrannosaurid it will be difficult to determine if its Trex or Nanotyrannus.   Hopefully someone has more info on this.

 

 

Thanks for the input, any ideas what that black substance could be? I don't think it's part of the trabecular bone...almost looks like some sort of tarry material that seeped in and filled some of the otherwise hollow pores in the trabecular bone. Is it consistent with any fossil material or Hell Creek Fm. matrix? It isn't occupying all the pores, just a bunch of them on one side; as you can see the pores on either end of the bone are indeed empty.

 

If so, and my bone does indeed exhibit the honeycomb structure, would it at best be identified as a Tyrannosaurid and either T. rex or Nannotyrannus, assuming the latter is valid? I did see your post @Troodon about Nanotyrannus likely being a valid genus distinct from T.rex. It seems there's some disagreement surrounding the subject, and though I am far too inexperienced to draw my own informed conclusions at the very least it seems one would need large limb, claw, jaw bones or teeth.

 

 

 

 

Edited June 17, 2022 by Mochaccino

[Troodon]

I would have responded in a different fashion if I knew what the black material was, I said I did not know, could definitely be filled in.  Nanotyrannus is very valid and sure there are different opinions why I put that topic together so that collectors can form their own opinions.    So is the claim that there are three possible Tyrannosaurus species in the HC.  (Paul et al. 2022)

 Sellers have a lot more to gain with Trex labeled specimen.

 

@jpc any thoughts on that black fill.  Hey get well.

[Rockwood]

Could  Gilsonite have stayed there long enough to be that age ? 

[jpc]

If I had found this isolated, I would think probably some sort of rex fragment.  

[Mochaccino]

20 hours ago, Troodon said:

I would have responded in a different fashion if I knew what the black material was, I said I did not know, could definitely be filled in.  Nanotyrannus is very valid and sure there are different opinions why I put that topic together so that collectors can form their own opinions.    So is the claim that there are three possible Tyrannosaurus species in the HC.  (Paul et al. 2022)

 Sellers have a lot more to gain with Trex labeled specimen.

 

@jpc any thoughts on that black fill.  Hey get well.

 

I see. Indeed, plenty incentive by sellers to label something specifically as T.rex. As you can probably tell from my original questions, I bought this not 100% expecting a definite T.rex identification despite the seller's claims. But it was cheap so I was still willing to go for it just to have a nice piece of Tyrannosaur bone that could potentially be T.rex. It just seemed like very nicely-preserved bone too.

 

19 hours ago, Rockwood said:

Could  Gilsonite have stayed there long enough to be that age ? 

 

I had to google gilsonite to find out what it is, but is this known to occur in the Hell Creek Fm? Seems like it's essentially solidified petroleum, interesting.

 

13 hours ago, jpc said:

If I had found this isolated, I would think probably some sort of rex fragment.  

 

Thanks for your assessment, may I ask what features would point you to think rex specifically? And do you have any idea what the black filling could be?

 

 

 

 

Edited June 18, 2022 by Mochaccino

[Rockwood]

1 hour ago, Mochaccino said:

I had to google gilsonite to find out what it is, but is this known to occur in the Hell Creek Fm? Seems like it's essentially solidified petroleum, interesting.

Mostly it is found in younger rocks of the Uinta basin. It seemed to fit here because of the appearance, and the fact that it might be mobile enough to invade the spaces.

[jpc]

My guess on the black infilling… manganese.  This is only a guess.

[Mochaccino]

14 hours ago, Rockwood said:

Mostly it is found in younger rocks of the Uinta basin. It seemed to fit here because of the appearance, and the fact that it might be mobile enough to invade the spaces.

 

8 hours ago, jpc said:

My guess on the black infilling… manganese.  This is only a guess.

 

Gotcha, thanks! Perhaps the seller also has any knowledge on what this could be.

[Mochaccino]

@Rockwood @Troodon @jpc The seller replied and says the black substance is something called Iron Siderite, essentially fossilized mud. So if this is the case it's indeed simply filling the otherwise empty pores. In retrospect I should have asked the seller first before making you guys guess. Thank you so much for your assessments and input. 

Edited June 19, 2022 by Mochaccino

[jpc]

siderite is NOT fossilized mud, it is an iron mineral, but, yes it could easily be siderite now that you mention it.

[Mochaccino]

2 minutes ago, jpc said:

siderite is NOT fossilized mud, it is an iron mineral, but, yes it could easily be siderite now that you mention it.

 

I see, I stand corrected (as well as the seller), thanks!

Edited June 19, 2022 by Mochaccino