Going to see the big mounted Alamosaurus next week

March 20, 2013

Mounted Alamosaurus in Dallas 1

Next week I’m going to visit the Perot Museum of Nature and Science in Dallas, Texas, to see their big Alamosaurus (these photos were kindly provided by Ron Tykoski of the Perot Museum, with permission to post). See that sweet string of cervical vertebrae in front of the mounted skeleton? A photo of those same vertebrae when they were still in the ground was featured in the post “How big was Alamosaurus?” three and a half years ago. Happily now they are out of the ground, prepped, and on display, and Tony Fiorillo and Ron Tykoski are working on getting them and some other new Alamosaurus material described.

Mounted Alamosaurus in Dallas 2

Here’s another view of that mount. You may be wondering, first, how legit is it, and second, how big is it? Happily, I have answers for you. In email messages with permission to cite, Ron Tykoski wrote,

The Alamosaurus skeletal mount by RCI  in the photos is based upon scaling the Smithsonian and UT Austin material to match the size of our cervicals here in Dallas.  There were enough overlapping parts between the pieces at the three institutions to get the proportions pretty nicely supported.

I ran across your SV-POW thread on ‘How big was Alamosaurus?’ back when you first posted it in ‘09.  You ought to be pleased to know that you came remarkably close to the eventual size of the skeleton we wound up with.  The full skeleton RCI generated (again, based off scaling to the Dallas verts) is 84ft long, about 16ft at the shoulder (I dropped a tape measure from the 1st dorsal neural spine to the floor during skeleton construction and got 480cm-490cm), and a neck + head of about 25ft.  The overall length and neck length were provided by RCI after fabrication and assembly.   That shoulder height is a bit suspect though based on the positioning of the pectoral girdle in the mount, relative to the ribcage and vert column.   I think the head currently is posed about 25ft or so off the floor, but I can’t verify that (I didn’t get into the scissor-lift to check that at the time).  This skeleton actually played a role in determining the size of the hall in which it is installed.  We decided early in the planning phase for the building that this skeleton would be the centerpiece for the hall.  As a result, the ceilings for this floor had to be made extra-high, and the mid-room support pillars designed out to accommodate the skeleton and still clear all the HVAC, sprinkler heads, and other necessities.

That’s all pretty fantastic–both that we have enough of Alamosaurus to do a pretty rigorous full skeletal mount, and that the beast was legitimately pretty darned big. Ron goes on:

One correction to the story on SV-POW, the Dallas cervical series consists of only 9 verts, not 10.  There may have been frags or something that made folks think there was a 10th at the anterior end of the series when first found, but I’ve never seen evidence of it in our collection.  This may be supported by the fact that the verts were given letter designations in the field (that we still use), and are identified as verts B through J, from anterior to posterior.

I later learned from Tony Fiorillo that the vertebrae were labelled B through J in the field in case anything anterior to B turned up, but nothing did, so the ‘A’ placeholder went unused. That reminds me of the search in the mid-1800s for the hypothetical planet Vulcan (not the one you’re thinking of) between Mercury and the Sun, which I bring up for no reasons other than that hypothetical planets are cool, and if you’re exploring, it’s worth keeping an open mind about what might yet turn up.

There’s more to say about the size of Alamosaurus–we haven’t even covered the big material described by Fowler and Sullivan (2011) yet–but I’m not going to say a whole lot right now, since I’m going to see the Big Bend material in Dallas in just a few days. Watch this space.

Reference

Fowler, D.W. and Sullivan, R.M. 2011. The first giant titanosaurian sauropod from the Upper Cretaceous of North America. Acta Palaeontologica Polonica 56 (4): 685–690.

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15 Responses to “Going to see the big mounted Alamosaurus next week”

  1. Mike Taylor Says:

    Titanosaurs certainly do have stupid cervicals.

  2. Dean Says:

    That is an awfully beautiful and impressive mount! Can’t wait to hear your take on the Fowler and Sullivan material!

  3. Adam Pritchard Says:

    Any idea which titanosaur skull was modeled for the mount?

  4. Mike Taylor Says:

    I love it that Matt’s chosen photos that give the skull no love at all. In one, it’s completely obscured by the neck; in the other, it’s tiny and distant and in near-total darkness.

    That said, the nearly-ventral aspect in the first photo has something of the anteriorly flared spoon shape of the Rapetosaurus skull (see Curry Rogers and Forster 2004:fig. 1C). Since that’s one of the best-known of all titanosaur skulls, I wouldn’t be surprised if it turned out that’s what they used.

    On the other hand, the ventral profile is not too different from that of Nemegtosaurus as restored by Wilson (2005:fig. 16D), so that’s a possibility. But I think it’s too long and thin to be the model for the Dallas skull.


  5. Man, I am super jealous, although hopefully I can go visit there this summer. Finally there is a nice large, titanosaur skeleton on display in the U.S., which is based off of relatively complete material! Happy days!

    I’ll be interested to see what the measurements are when these cervicals are finally published. I had that individual as pegged at around 20 meters, not 26, although I think the largest specimens probably got that size. I had to more or less guess based off of photos when I incorporated them into my skeletal. The tail looks a bit longer proportionally than I reconstruct it as well.


  6. […] I noted in a comment on the previous post, titanosaurs have stupid […]

  7. Ronald12 Says:

    I must admit that I am a bit disappointed with the shoulder height of this mounted skeleton, because Matt Wedel estimated this individual to be considerably taller 3 1-2 years ago, based on the same cervical column and a known subadult (quote):

    Total length: 24 meters (79 feet)
    Neck length: 7.8 meters (25.5 feet)
    * •Shoulder height: 6 meters (19.5 feet)*
    Head height: 12.6 meters (41 feet)

    But we will wait anxiously for next week (?), ánd the coverage of the Fowler and Sullivan material.

  8. Matt Wedel Says:

    I must admit that I am a bit disappointed with the shoulder height of this mounted skeleton, because Matt Wedel estimated this individual to be considerably taller 3 1-2 years ago, based on the same cervical column and a known subadult

    Some of that difference has to do with posture. If you look at the photos above, both forelimbs are noticeably flexed, whereas in the skeleton recon from Lehman and Coulson (2002) that I was using for my estimates back when, they are much less so, and the left forelimb is almost straight.

    Also, the mounted skeleton in Dallas is not a perfect reproduction of the Lehman and Coulson figure. There are big differences going from a 2D drawing to a life-size 3D skeleton, and stuff like the position and angle of the scapula can end up having a pretty big effect on the shoulder height. I note that in the figure, the end of the scap is about level with the transverse processes of the dorsal vertebrae, whereas in the mount the end of the scap seems to be level with the tops of the dorsal neural spines.

    I’ll try to get some good lateral views of the mount with as little perspective as possible. By taking those into GIMP and playing with them, it should be possible to figure out how much the forelimb pose and scap position are influencing the shoulder height. But I’ll make a prediction right now, which is that if the mount had straight forelimbs and the scap in the same position as the Lehman and Coulson illustration, the shoulder heights would be within 5% of each other.

    Now we can check back in a week or so and see if I was right. :-)

  9. Ron Tykoski Says:

    Matt is not to blame for disrespecting the head in those photos – there’s only one place in the exhibit hall where you can take a picture of almost the entire skeleton without a wide-angle lens! Mike’s suspicions are correct in that Rapetosaurus was used as the model for the skull. RCI already had digitally scanned that material, so it was a convenient stand-in for us.

    As far as tail length and proportions go, the anterior part of the tail is based off of scans of the Smithsonian material. The rest of the tail is based on a South American titanosaur specimen (no, I don’t know which one) digitized by RCI that they say preserves the entire tail. It has a heck of a long, whiplash-like tip on it. So that undoubtedly contributes to the elongation of our mount relative to expected results.

    Matt correctly points out that the mount doesn’t attempt to replicate the Lehman and Coulson illustration in its pose and pectoral posture. We had limitations with regard to ceiling and infrastructure height, and also wanted to pose the beastie in such a way as to make it look a bit dynamic and interacting with the cast of the Tyrannosaurus (MOR 555) next to it. The exhibit shows a predator-prey interaction in Big Bend National Park in the latest Cretaceous versus some modern counterparts from the same place. The T. rex was posed as if it is about to lunge to try and nip at the left elbow of the Alamosaurus, so it was decided that a straight-legged, stiff pose for the latter would look a bit odd and non-reactive to the threat. That’s also why the head and neck turn that way (away from the camera – sorry!), as if to ask “Who the heck is pestering me down there?”

  10. Matt Wedel Says:

    Thanks for all the info, Ron.

    Just to be clear, when I wrote, “the mounted skeleton in Dallas is not a perfect reproduction of the Lehman and Coulson figure”, I didn’t mean to imply that it should have been. I just meant that you draw things and get one result, and then go put the real bones together and get something different, and that is perfectly natural and should not come as a surprise to anyone.

  11. Matt Says:

    Thank you for the post about the Alamosaurus display. It is great to know that there is now a large mounted titanosaur in a U.S. museum. This would indeed be a great sauropod specimen to see.
    After viewing the photos of this mount and reading about sauropod phylogeny, I find titanosaurus to be more puzzling, recent phylogenetics place them as being devired from Brachiosaurids. However, if you look at Titanosaur morphology, they do indeed resemble diplodocids, similar to McIntosh’s original classification of the group. So what is going on with this particular group? Are they Brachiosaurids that devolped diplodocid-like morphology, and filled in the niche left vacant by Late Jurassic/Early Cretaceous extinctions? I’m just taking a guess here, but I find the whole osteology of Titanosaurs puzzling when looked at from a phylogenetic perspective. Again, it shows how unique sauropods really are.


  12. […] Matt’s off to see this guy, and I couldn’t find my post (bad blogging, bad) via search queries, here a repost of my […]

  13. dobermunk Says:

    From the big guy’s stop-over in Frankfurt:
    http://www.drip.de/?p=2729

  14. Mike Taylor Says:

    I don’t think anyone’s argued that titanosaurs are derived brachiosaurs; rather, that they are sister groups, the two great branches within the group Titanosauriformes. (Well: it’s slightly more complicated than that, depending on what definitions you use. The sister group to Brachiosauridae is usually called Somphosopondyli, but that is the group that contains titanosaurs.

    And yes, some aspects of the osteology of some titanosaurs does resemble diplodocids, especially the “pencil-like” teeth. But overall they are very different animals.

  15. Mike Taylor Says:

    From the big guy’s stop-over in Frankfurt:
    http://www.drip.de/?p=2729

    Ugh. The cervical ribs on that thing cause me physical pain.


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