BIBE 45854, the giant Alamosaurus cervical series from Big Bend, Texas

March 9, 2018

Back in 2009, I posted on a big cervical series discovered in Big Bend National Park. Then in 2013 I posted again about how I was going to the Perot Museum in Dallas to see that cervical series, which by then was fully prepped and on display but awaiting a full description. Ron Tykoski and Tony Fiorillo (2016) published that description a couple of years ago, and after almost five years it’s probably time I posted an update.

I did visit the Perot Museum in 2013 and Ron and Tony kindly let me hop the fence and get up close and personal with their baby. I got a lot of nice photos and measurements of the big specimen. It’s an impressive thing. Compared to the other big sauropod cervicals I’ve gotten to play with, these vertebrae aren’t all that long – the two longest centra are about 80cm, compared to ~120cm for Sauroposeidon, Puertasaurus, and Patagotitan, and 137cm for Supersaurus (more details here) – but they are massive. According to the table of measurements (yay!) in Tykoski and Fiorillo (2016), which accord well with the measurements I took when I was there, the last vert is 117.5cm tall from the bottom of the cervical rib to the top of the neural spine, 98.4cm wide across the diapophyses, and has a cotyle measuring 29cm tall by 42cm wide. Here it is with me for scale:

I guarantee you, standing next to that thing and imagining it being inside the neck of a living animal is a breathtaking experience.

I failed in my mission in one way. In a comment on my 2013 post, I said, “I’ll try to get some good lateral views of the mount with as little perspective as possible.” But it can’t be done – the geometry of the room and the size of the skeleton don’t allow it, as Ron noted in the very next comment. There is one place in the exhibit hall where you can get the whole skeleton into the frame, and that’s a sort of right anterolateral oblique view. Here’s my best attempt:

So, this is an awesome specimen and you should go see it. As you can see from the photos, the vertebrae are right on the other side of the signage, with no glass between you and them, so you can see a lot. The rest of the exhibits are top notch as well. Definitely worth a visit if you find yourself within striking distance of Dallas.

Reference

Tykoski, R.S. and Fiorillo, A.R. 2016. An articulated cervical series of Alamosaurus sanjuanensis Gilmore, 1922 (Dinosauria, Sauropoda) from Texas: new perspective on the relationships of North America’s last giant sauropod. Journal of Systematic Palaeontology 15(5):339-364.

22 Responses to “BIBE 45854, the giant Alamosaurus cervical series from Big Bend, Texas”

  1. Mike Taylor Says:

    The striking thing about this cervical sequence is how relatively little morphological difference there is along the neck: the vertebrae seem to be slightly-differently-scaled models of each other, in comparison with for example the much greater variation along the neck of Diplodocus.

    That thought occurred to me based on your photos above, but in fact the published illustrations seem to bear it out.

  2. Matt Wedel Says:

    Yeah, totally. What’s really striking to me is that all of the vertebrae look like the posterior cervicals of something like Malawisaurus, like there has been a wave of posterior-cervical-ization sweeping up the column.

    I don’t know what the advantage would be there. If you think about something like Plateosaurus or even Shunosaurus, the cervicals vary much less along the column than they do in most neosauropods. Diplodocus is a great example, maybe the best available, of pronounced morphological change along the cervical series. I get why that would be advantageous. It’s much less obvious why – presumably having passed through a Malawisaurus-like stage with differentiated cervicals – at least some derived titanosaurs seem to have less disparity along their cervical series. Possibly some complex muscle/tendon/air sac/bone interaction that we are not likely to figure out anytime soon.

  3. Crown House Says:

    Hi, I just wanted to thank you for your work! And it’s great to have new vertebra pictures, please don’t stop posting them! I don’t know, how and when exactly it happened, but a couple of years ago I got hooked and am enjoying every one of them.
    Thanks again!

  4. Matt Wedel Says:

    Thank you for the kind words!

  5. Andrew Stuck Says:

    My Perot membership recently expired; I really need to renew it. The Perot is quite excellent, and I love seeing the Alamosaurus every time. I like they have both the mount and the actual neck vertebrae displayed next to each other!


  6. […] in 2013 I went to the Perot Museum in Dallas to see the giant Alamosaurus cervical series, and I also visited the off-site research facility where juvenile Alamosaurus from Big Bend is […]

  7. Dimitris Says:

    Dear SVPOW members.

    I am a young paleoartist from Greece. I’m sorry to bother you but I needed some sauropod experts to answer me two questions I have about Alamosaurus.

    1) Since Alamosaurus is a derived titanosaur, how possible is it that it had an unusual number of cervicals? This feature already appears on Rapetosaurus and Dongbeititan. Does this mean that it’s a general feature of derived titanosaurs (such as Saltasaurus, Isisaurus etc.)?

    2) I have seen some unusual artworks of Alamosaurus on Deviantart, like this one. How possible is this massive neck? I mean it does look quite off proportion, but there could be some indication that it was the normal in this case. https://www.deviantart.com/getawaytrike/art/Ragnarok-619051050

  8. Mike Taylor Says:

    Hi, Dimitris, great to hear from you.

    1. Number of cervicals is a pretty labile character among sauropods. I don’t know offhand how complete our best Alamosaurus necks are, though this sequence of nine is pretty impressive. In the absence of a complete neck I’d say there’s decent leeway in the cervical count. The 14 in the reconstruction you reference here doesn’t seem unreasonable.

    2. That reconstructed neck looks crazy tall, but you can see for yourself in the linked post that it’s accurate. Would have been wide, too. But as the DeviantArt comments note, the torso may be proportionally too small. The bit of that piece that bothers me is the very abrupt cervicodorsal transition.

  9. Dimitris Says:

    It seems like cervical number remained steady at 12-14 and increased a few times, like in mamenchisauridae and euhelopodidae. Considering Dongbeititan and Rapetosaurus I find it possible that the same trait also appeared in saltasaurids, possibly including Opisthocoelicaudia and Alamosaurus.

    The same abrupt transition seems to exist on the Perot Museum version to a smaller degree. The cervical spines start too tall at the base of the neck. https://www.tandfonline.com/doi/pdf/10.1080/14772019.2016.1183150 Scott Hartman on the other hand made the transition rather smooth. He is more conservative with neck size.


  10. […] and fat. It was left to me to represent for sauropods, with posts on the cervical vertebrae of Alamosaurus and Suuwassea and some noodling about sauropod […]

  11. Brad Lichtenstein Says:

    Ok, finally back at the Perot museum after reading this post. Nature is what it is, and I’m still not an expert here – sadly, I wasn’t elected Gd, not even for a day… The full alamosaurus reconstruction struck me as looking like two conjoined vertebrae were intimately trying to strangle each other. Looking at the actual specimens, it really looks like they left big “floofs” of rock on the outside of the actual bone structure. But I’m sure they were better trained in fossil prep. Nice to look at it fairly closely though. Finally.

  12. Brad Lichtenstein Says:

    Is that possibly ossified tendon/ligament still attached to proper “bone”, like the cervical ribs?

  13. Mike Taylor Says:

    Is the feature you’re describing here visible in any of Matt’s photos? Which one? Where, exactly?

  14. Rugosidens Excelsus Says:

    Ah, Perot, it’s been too long… I really need to get back over there, someday…

  15. Brad Says:

    Mike: any of the anterior and posterior views in the post: the tops of the neural “spines” look like domes or leaves in cross section, and to switch analogies, some look like kids’ lollipop tree drawings, where you can clearly see the “trunk” well into foliage blob. If the cervical ribs are ossified tendons, it would make sense the stronger erector muscles would do the same thing. I just don’t recall seeing anything like it before

  16. Mike Taylor Says:

    Yep. Without having seen the fossils myself I don’t want to be too certain about this, but I think all that gnarliness is just good, old-fashioned ligament attachment area. The interesting thing is that in these vertebrae it’s all lateral to the midline, whereas in (for example) Brachiosaurus dorsals, the ligament rugosity is an area ON the midline. Not sure what to make of that. Matt?

  17. Matt Wedel Says:

    I can confirm that all of those vertebrae are fully prepped. Whatever gnarliness remains is legit gnarliness present in the bone, not from attached bits of rock. But you could be excused for thinking that, because the preservation is unusual, with an unusual amount of texturing that’s not often present in well-preserved fossils. The baby Alamo stuff from Big Bend is the same way. I wonder if the bones either sat exposed for a while before burial, so that the cortical bone broke up a bit prior to fossilization, or if they were in water for a while and the same thing happened.

    As for these things having just massive areas of rugose bone that looks like it was attaching ligaments and muscles — yep, that interpretation is almost certainly correct, but how (and why) you get from the ancestral neosauropod to this, as opposed to Diplodocus or Brachiosaurus with their more reasonable-looking vertebrae, is quite beyond my capacity.

  18. Mike Taylor Says:

    You know what, dude? Someone really oughtta get to grips with the problem in intervertebral ligaments and muscles in sauropod necks.

  19. Brad Lichtenstein Says:

    For the record, I assumed the prep people were professionals, altho having …maybe never… seen large fossils up close (I’m tall and can lean in), I was struck that it all looked a lot like a rough carved, cracked piece of granite, which would be impossible for a fossil. …and begs another caveat: that is my recollection 4 days after the fact, and I’m a noob, hopefully an appreciative one. I mean, watching the volunteers do prep work in the next room, I was struck by the question of, “how do they know when to stop picking away? …or when to start??” Their “crumbly granola bar” (their term) still partly in plaster looked frightening, and I enjoy a good 3-D puzzle.

    Matt: all that aside, ok, it was bone at time of fossilization, but do you think it was born that way as part of the vertebrae as structural support for soft tissue attachments, or was it the attached soft tissue itself ossifying as the animal grew larger? I get there’s likely room for either speculation or quashing the question (“bone is bone, you bonehead noob!”).

    And everyone else: if I’m boring you, I apologize for the spam.

  20. Matt Wedel Says:

    it was bone at time of fossilization, but do you think it was born that way as part of the vertebrae as structural support for soft tissue attachments, or was it the attached soft tissue itself ossifying as the animal grew larger?

    That is a fantastic question. I can think of two ways to answer it: look at juvenile material to see if it has the same texture, or do histo on the adult material–ossified tendons and ligaments generally have a different appearance from endochondral bone, as long as they haven’t been too heavily remodeled.

    Of the two, I’d think the juvenile material would give a more pure answer, and without destructive sampling.

  21. Mike Taylor Says:

    An excellent question indeed, Brad: “if I’m boring you, I apologize for the spam” could hardly be a less appropriate characterization! If this blog is not the place for speculating on the ontogenetic ossification trajectory of sauropod cervicals, where is?!


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