Is this a Spinosaurid partial spine? (Round 2)

[-Andy-]

Hi all, I have another fossil here for your inspection please. It seems to be a Spinosaurid partial neural spine but I cannot be sure.

 

 

@Troodon @LordTrilobite

[LordTrilobite]

I'm not sure Carcharodontosaurid could be completely ruled out. Some Carcharodontosaurids have pretty long spines as well. But it might be too slender.

 

But yes, this does indeed look like a portion of a Spinosaurid neural spine. The shape and structure fits. Spinosaurid spine seems most likely.

 

 

Edit: then again... For Carcharodontosaurid I would kinda expect tendon attachments on the front and back of the spine. Since this one doesn't have that we can probably rule out Carcharodontosaurid after all. So Spino spine it is!

[Troodon]

Agree Spinosaurid spine, fits the profile of the one I have.

[Masp]

Very nice fossil, congrats on this @-Andy-

[-Andy-]

@hxmendoza spoke to me on Facebook, explaining why this is likely a Spino spine. With his permission, I will summarize his words:

 

 

In this video, at 0:37 mark, Paul Sereno holds up a partial spine. Also, the marrow in the Spinosaurus neural spins is a thin line as seen in this cross section:

 

The neural spine of the new specimen that was reported by Ibrahim and Sereno, was used to match up with the exact corresponding segment on the rest of the specimen that was excavated by the Moroccan digger that originally found it. If memory serves, it’s in the National Geographic documentary of the find. 

 

Ribs have a more wider area of bone marrow occupying the space within. The specimen I posted is pretty symmetrical and thin in cross section as would be expected in a neural spine:

 

This are cross sections of dinosaur ribs:

 

Here is a cross section of a sauropod scapula. Note the amount of space the bone marrow cavity takes up:

 

This is a neural arch from Spinosaurus that has the remnant of the base of a neutral spine. The cross section of the bone marrow matches my specimen:

 

The cleft is where there is a natural groove at the base of the neural spine:

 

[LordTrilobite]

More spino reference. The same thin band of marrow can be seen on the top of the broken end of the spine base here, although it's not as clear in the texture here. It seems to influence how the spine breaks as well.