Neck ontogeny in Tyrannosaurus rex

March 14, 2019

Having spent much of the last few days playing with the cervical vertebrae of a subadult apatosaur, and trying to make sense of those of the mounted adult, neck ontogeny is much on our minds. Here’s an example from the less charismatic half of Saurischia.

I was forcibly struck, when seeing a cast of Jane the juvenile Tyrannosaurus in the museum gift-shop, by how weedy its neck is:

This being the Carnegie Museum, it was with us the work of a moment to scoot across to the Cretaceous gallery and compare with the neck of an adult, CM 9380:

As you can see, the transformation of the neck is every bit as dramatic as that of the skull, as a slender animal optimised for pursuit grows into a total freakin’ monster.

Someone ought to quantify this. I’m talking to you, theropod workers! (We’ll be busy over here with sauropods.)

Here are the full, uncropped and uncorrected, versions of the photos that I extracted the above from:

This is truly a magnificent museum.

13 Responses to “Neck ontogeny in Tyrannosaurus rex

  1. Zachary Miller Says:

    Because obviously, they’re different taxa, Mike.

    (I’m kidding)

  2. Mike Taylor Says:

    I think I’m right in saying that the identity of Jane as a Tyrannosaurus has not been seriously questioned. It’s different from “Nanotyrannus“.

  3. David Hone Says:

    Mike you are thinking of Nanotyrannus (Darren will be annoyed you have mixed it with his Eotyrannous from the IoW!). Yes, the general consensus is Jane is a juvy rex but I do think some people do still refer it to Nanotyrannus.

  4. Devin Myers Says:

    I’d wager at least every other popular dinosaur book written by a non-specialist (especially the ones for kids) mention Jane and Nanotyrannus in direct relation to each other. The impression I get talking to a lot of people with a general interest in dinosaurs is that Jane is their go-to image when thinking of Nanotyrannus, whether they think it is valid or not.

  5. Mike Taylor Says:

    Argh! Dave, you are of course right that I was thinking of Nanotyrannus. The “Eo” was a brain-fart which I shall now go back and correct.

    (Although let the record show: my original claim that “It’s different from ‘Nanotyrannus‘” is also true :-)

  6. Eric Snively Says:

    Yes! We need deep 3D morphometrics for saurischian necks. The neural spine differences are obvious (semi-quantified here:, but check out the transverse processes!

  7. saurian Says:

    Tyrannosaurid cervicals are a mess – but in a good way!

  8. […] Fossil Friday – dinosaur tibia Neck ontogeny in <i>Tyrannosaurus rex</i> […]

  9. “Here’s an example from the less charismatic half of Saurischia.”

    Ornithoscelida says hi.

  10. Mike Taylor Says:

    Yeah, Ornithoscelida doesn’t really seem to have caught on, does it?

    I don’t really know what the present state of that debate is.

  11. This is a pretty good read on that:

    Some have said there were problems with the OG matrix but I’ve no clue what those could be especially considering the much greater sample size of basal dinosaurs compared with Seeley’s data. I think it’s a safe bet that Ornithoscelida is pretty likely to exist.

  12. Mike Taylor Says:

    I have no dog in this fight. I’m just observing that the wider world doesn’t seem to have leapt on board the Ornithscelida train.

  13. Ah, I see.
    You’re indeed correct that it hasn’t caught on. Not really at all.

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