The femur of Argyrosaurus, maybe
November 1, 2021
FMNH P13018 with me for scale. Photo by Holly Woodward.
Some of the Burpee Museum folks and PaleoFest speakers visited the Field Museum of Natural History in Chicago after the 2020 ‘Fest. I hadn’t been there since 2012, and a lot had changed. More on that in future posts, maybe. Here I am with FMNH 13018, a right femur referred by von Huene (1929) to Argyrosaurus superbus (note, though, that Mannion and Otero 2012 considered this specimen to be Titanosauria indet., hence the hedge in the title of the post). It’s 211cm long, which is pretty darn big but still well short of the record.
Speaking of the record, here’s a list of the largest sauropod femora (as always, updates in the comments are welcome!):
- 250cm – Argentinosaurus huinculensis, MLP-DP 46-VIII-21-3 (estimated when complete)
- 238cm – Patagotitan mayorum, MPEF-3399/44
- 236cm – Patagotitan mayorum, MPEF-PV 3400/27
- 235cm – Patagotitan mayorum, MPEF-PV 3400/27
- 235cm – “Antarctosaurus” giganteus, MLP 26-316
- 214cm – Giraffatitan brancai, XV1
- 211cm – cf. Argyrosaurus superbus, FMNH P13018
- 203cm – Brachiosaurus altithorax, FMNH P25107
- 200cm – Ruyangosaurus giganteus, 41HIII -0002 (estimated when complete)
- 191cm – Dreadnoughtus schrani, MPM-PV 1156
The list is necessarily incomplete, because we have no preserved femora for Puertasaurus, Notocolossus, Futalognkosaurus, or the largest individuals of Sauroposeidon and Alamosaurus, all of which probably had femora in the 210-250cm range. For that matter, most elements of the giant Oklahoma apatosaurine are 25%-33% larger than the equivalent bones in CM 3018, which implies a femur length of 223-237cm (scaled up from the 178.5cm femur of CM 3018). I’m deliberately not dealing with Maraapunisaurus or horrifying hypothetical barosaurs here.
In any case, it’s still a prodigious bone, and well worth spending a moment with the next time you’re at the Field Musuem.
References
- Mannion, P.D. and Otero, A., 2012. A reappraisal of the Late Cretaceous Argentinean sauropod dinosaur Argyrosaurus superbus, with a description of a new titanosaur genus. Journal of Vertebrate Paleontology, 32(3):614-638.
- Von Huene, F. 1929. Los saurisquios y ornitisquios del Creta´ceo Argentino. Anales del Museo de La Plata 3:1–196.
Spinal cord blank diagrams, and the Field Museum Patagotitan
November 5, 2020
Here are some blank diagrams I whipped up for drawing in spinal cord pathways.
This one shows the whole cord, brainstem, thalamus, and cerebral cortex in coronal section, in cartoon form.
It’s for drawing in ascending sensory and descending motor pathways, as shown in this office hours sketch. DC-ML is dorsal column/medial lemniscus, which carries discriminative touch and conscious proprioception. ALS is anterolateral system, which carries pain, temperature, pressure, and itch. The lateral corticospinal tract carries fibers for voluntary control of major muscle groups. Each pathway differs in terms of where it decussates (crosses the midline, left-to-right and vice versa) and synapses (relays from one neuron to the next). The sensory pathways involve primary, secondary, and tertiary sensory neurons, and the motor pathways involve upper motor neurons (UMNs) and lower motor neurons (LMNs).
This one shows cross-sections of the cord at cervical, thoracic, lumbar, and sacral levels, for drawing ascending and descending pathways and thinking about how patterns of somatotopy come to exist.
Somatotopy is the physical representation of the body in the central nervous system. A common abbreviation scheme is A-T-L for arm-trunk-leg, as shown here for ascending sensory and descending motor pathways.
Finally, this one shows the spinal cord and spinal nerve roots at four adjacent spinal levels, for tracking the specific fates of sensory and motor neurons at each spinal level.
This is particularly useful when working out the consequences of an injury, like the spinal cord hemisection (Brown-Sequard syndrome) shown here in pink. The little human figure only shows the zone in which pain and temperature sensation are lost. There would also be losses of discriminative touch, conscious proprioception, and voluntary motor control on the same side as the injury.
Finally, since we’ve had a bit of a sauropod drought lately, here are a couple of photos of the mounted cast skeleton of Patagotitan in Stanley Field Hall at the Field Museum of Natural History in Chicago.
I gotta say, this mount beats the one at the AMNH in every way, because it’s well lit and you can move all the way around it and even look down on it from above. In fact, in terms of getting to move all the way around it, get well back from it to see the whole thing at once, and even walk directly underneath it (without having to ask permission to hop the fence), it might be the best-mounted sauropod skeleton in the world. The Brachiosaurus outside is also pretty great (evidence), but it loses points because you can’t walk around it on an upstairs balcony. Every other mounted sauropod I know of is either in more cramped surroundings, or you can’t get underneath it, or is less well-lit, or some combination of the above. Am I forgetting any worthy contenders? Feel free to make your case in the comments.
Incidentally, the spinal cord of Patagotitan was something like 120 feet long, and the longest DC-ML primary sensory neurons ran all the way from tail-tip to brainstem before they synapsed, making them among the longest cells in the history of life.
A belated thank-you to Josh Matthews and the rest of the Burpee PaleoFest crew for a fun day at the FMNH back in March. I got home from that trip about 3 days before the pandemic quarantine started, so it’s waaaaay past time for me to blog about how awesome that trip was. Watch this space. UPDATE: hey, look, it only took me a third of a year this time! Link.
Storm Giant
March 12, 2020
Matt’s Brachiosaurus in the wild
February 16, 2020
No, not his new Brachiosaurus humerus — his photograph of the Chicago Brachiosaurus mount, which he cut out and cleaned up seven years ago:
This image has been on quite a journey. Since Matt published this cleaned-up photo, and furnished it under the Creative Commons Attribution (CC By) licence, it has been adopted as the lead image of Wikipedia’s Brachiosaurus page [archvied]:
Consequently (I assume) it has now become Google’s top hit for brachiosaurus skeleton:
Last Saturday, Fiona and I went to Birdland, a birds-only zoo in the Cotswolds, about an hour away from where we live. The admission price also includes “Jurassic Journey”, a walking tour of a dozen or so not-very-good dinosaur models. In an interpretive centre in this area, I found this Brachiosaurus skeletal reconstruction stencilled on the wall:
I immediately knew it was the Chicago mount due to the combination of Giraffatitan anterior dorsals and Brachiosaurus posterior dorsals; but I found it more hauntingly familiar than that. A quick hunt turned up Matt’s seven-year-old post, and when I told Matt about my discovery he filled me in on its use in Wikipedia.
So this is 99% of a good story: we’re delighted that this work is out there, and has resulted in a much better Brachiosaurus image at Birdland than the rather sad-looking Stegosaurus next to it. The only slight disappointment is that I couldn’t find any sign of credit, which they really should have included given that Matt put the image out under CC By rather than in the public domain.
But as Matt said: “Even though I didn’t get credited, I’m always chuffed to see my stuff out in the world.” So true.
The proximal caudals of Brachiosaurus altithorax, FMNH P25107
September 11, 2018
Left lateral view
Have we ever posted decent photos of the Brachiosaurus altithorax caudals? Has anyone? I can’t remember either thing ever happening. When I need images of brachiosaur bits, including caudals, I usually go to Taylor (2009).
Taylor (2009: fig. 3)
Which is silly, not because Mike’s diagrams compiling old illustrations aren’t good – they definitely are – but because I’m sitting on a war chest of decent photos of the actual material. I am home sick with a sore throat today, and I can’t be arsed to (1) follow up on the “Down in Flames” post, (2) add anything thoughtful to the vertebral orientation discussion, or (3) crop or color-adjust these photos. You’re getting them just as they came out of my camera, from my trip to the Field Museum in 2012.
Here are the rest of the orthogonal views:
Right lateral view
Anterior view
Posterior view
Dorsal view of caudal 1
Dorsal view of caudal 2
And here’s a virtual walkaround using a series of oblique shots. Making a set like this is part of my standard practice now for important specimens during museum visits.
Now, I said up top that I wasn’t going to add anything thoughtful to the vertebral orientation discussion. I have thoughts on that, but I’m tired and hopped up on cold medicine and now ain’t the time. In lieu of blather, here are a couple of relevant photos.
I wanted to capture for my future self the pronounced non-orthogonality of the neural canal and centrum, so I rolled up a piece of paper and stuck it through the neural canal. I haven’t run the numbers, but in terms of “angle of the articular faces away from the neural canal”, these verts look like they’re right up there with my beloved Snowmass Haplocanthosaurus.
More on that next time, I reckon. In the meantime, all these photos are yours now (CC-BY, like everything on this site [that someone else hasn’t asserted copyright over]). Go have fun.
Reference
Left side, posterolateral oblique view, wide shot.
Same thing, close up.
Right side, lateral, wide.
Same thing, close up.
For more on this and other pneumatic sauropod tails, please see Wedel and Taylor (2013, here). And for more on the currently unresolved taxonomic status of FMNH P25112, see this post.
YPM 1980: Brontosaurus excelsus, the animal formerly known as Apatosaurus excelsus, the animal formerly known as Brontosaurus excelsus.
Today is a good day for sauropod science. Since we’re not getting this up until the afternoon, you’ve probably already seen that Emanuel Tschopp and colleagues have published a monstrous specimen-level phylogenetic analysis of Diplodocidae and, among other things, resurrected Brontosaurus as a valid genus. The paper is in PeerJ so you can read it for free (here).
I’ve already been pinged by lots of folks asking for my thoughts on this. I know that the return of Brontosaurus is what’s going to catapult this paper into the spotlight, but I hope what everyone takes away from it is just what a thorough piece of work it is. I’ve never seen so many phylogenetic characters illustrated so well. It sets a new standard, and anyone who wants to overturn this had better roll up their sleeves and bring a boatload of data. I’m also very, very happy that it’s open-access so everyone in the world can see it, use it, question it, tear it apart or build on it. Getting Brontosaurus back is just gravy. Although, being pro-brontosaur enough to have named a dinosaur in honor of Brontosaurus, I’m also pretty happy about that. If you need a quick guide to who’s who now, A. ajax and A. louisae are still Apatosaurus, and B. excelsus, B. yahnahpin (formerly Eobrontosaurus), and B. parvus (originally Elosaurus) are all Brontosaurus. For more details, go read the paper.
Apatosaurus lousiae CM 3018: still Apatosaurus. Photo from Wikipedia.
My personal feelings aside, a lot of people are asking how solid is this generic re-separation. I haven’t read the entire paper yet – it’s 299 pages long, for crying out loud – but the separation of Brontosaurus and Apatosaurus seems solid enough. Tschopp et al. didn’t do it lightly, they justify their decision in detail. I don’t hold with the idea that just because two taxa are sisters, means that they cannot be separated generically. As usual in phylogenetic taxonomy, it comes down to what we decide as a community constitutes “diagnosably distinct”. Tschopp et al. have actually put some thought into what that might mean here, and whether you agree with them or not, they’ve at least made all of their evidence and reasoning explicit. That’s both an opportunity and a challenge for critics: an opportunity to pin down exactly where and why you may disagree, and a challenge to do exactly that. You can’t just sit back and say, “I think the analysis is flawed” or “I wouldn’t have coded that character that way” (well, you can, but if that’s all you say, no-one is obliged to take that kind of lazy, drive-by criticism seriously). There are 477 characters here, most of them illustrated, for 81 OTUs, and a lot of post-hoc discussion of the results. So whether you agree with the authors or not, in whole or in part, both fans and critics should dig in and build on this work. Is it the last word on diplodocid taxonomy? Of course not. But it does move the field forward significantly, and the Tschopp et al. should be applauded for that.
There’s a lot more in there than just bringing back Brontosaurus. “Diplodocus” hayi is elevated to its own genus, Galeamopus. Neither of those things are super surprising. There have been rumors since the 90s at least that Brontosaurus might be coming back, and everyone has known for a while that D. hayi was a bit wonky. I was also not surprised to see Australodocus returned to Diplodocidae – when I saw the type material in 2011, it looked diplodocid to me (based on some characters I’ll have to unpack in some other post). More surprising to me are the sinking of Dinheirosaurus into Supersaurus, the finding that Tornieria is not particularly close to Diplodocus, and the uncertain positions of AMNH 460, the American Museum mount, which is an indeterminate apatosaurine pending further study, of FMNH 25112, the Field Museum “Apatosaurus”, which might not even be an apatosaurine at all(!). In several cases, Tschopp et al. come right out and say that X is going to need further study, so if you want to work on sauropods and you’re stuck for project ideas, go see what needs doing.
AMNH 460: we don’t know who this is anymore.
As I was scanning the paper again while composing the last paragraph, I almost fell down the rabbit hole. So much interesting stuff in this paper. Even if all you care about is morphology, the hundred or so figures illustrating the phylogenetic characters ought to keep you happy for a very long time. I look forward to reading through the vertebral characters in detail and seeing what I’ve been missing all these years.
I’m contractually obliged to point out that the authors chose to publish the complete peer-review history of the paper, so you can see what the editor (Andy Farke) and reviewers had to say. As always, I think this transparency (and credit for the reviewers) is great for science, and I can’t wait until it’s the norm at more journals.
FMNH 25112: what even IS that thing?
In addition to the paper, there’s also an interview with lead author Emanuel Tschopp on the PeerJ blog, and a nice shout-out for SV-POW!
Parting shot: why did Tschopp et al. get different results than anyone had previously? Because they used more specimens and more taxa – more data full stop. That’s also why their paper warrants serious consideration. It’s serious work. Let’s go stand on their shoulders.
Reference
(2015) A specimen-level phylogenetic analysis and taxonomic revision of Diplodocidae (Dinosauria, Sauropoda) PeerJ 3:e857 https://dx.doi.org/10.7717/peerj.857
In recent photo posts on the mounted Brachiosaurus skeleton and its bones in the ground, I’ve lamented that the Field Museum’s online photo archive is so unhelpful: for example, if it has a search facility, I’ve not been able to find it.
But the good news is that there’s a Field Museum Photo Archives tumblr. Its coverage is of course spotty, but it gives us at least some chance of finding useful brachiosaur images. Like this one of the sixth presacral vertebra (i.e. probably D7 in a column of 12 dorsals):
It’s instructive to compare that with Riggs’s (1904: plate LXXII) illustration of the same vertebra in the same aspect, in which he almost literally airbrushed out the jigsaw-puzzle complexity of the preserved bone surface:
More disturbing still, compare that old photograph with my own (terrible) 2005 photo of the same vertebra:
It looks very much as though the vertebra itself — not just Riggs’s illustration — has been “improved” since the older photo was taken exactly a century earlier in 1905. This is a constant problem when dealing with old fossils.
Here are three more interesting photos from the Tumblr. First, the Brachiosaurus fossils in the field:
This is evidently from later in the excavation process than the previous photo of this area, since much of the material is now jacketed. That’s the femur in front of shot, here seen in anteromedial view, with the top towards the right.
Next up, this photo purports to be “Thirteen men including Security Guard unloading dorsal vertebrae of type specimen Brachiosaurus fossil”:
But in fact it’s not Brachiosaurus — the neural spines are too tall and slender. I am pretty sure this is Riggs’s Apatosaurus — the rightmost dorsal has that distinctive notch on the dorsal aspect of the neural spine. And indeed, checking his monograph on that specimen (Riggs 1903: plate XLVI), I see that its dorsals were distorted in this way, and that the front-centre vert is a fine match for its D10.
Finally, there’s this one of the prep room:
On the far left, we have the still-jacketed Brachiosaurus femur; next to it stands Harold W. Menke, who discovered the fossil; and to his right is Elmer S. Riggs, who wrote the description.
Those are all the Brachiosaurus-related images I’ve been able to find on the tumblr. But do let me know if you find any others.
References
- Riggs, Elmer S. 1903. Structure and relationships of opisthocoelian dinosaurs. Part I: Apatosaurus Marsh. Field Columbian Museum, Geological Series 2:165-196.
- Riggs, Elmer S. 1904. Structure and relationships of opisthocoelian dinosaurs. Part II, the Brachiosauridae. Field Columbian Museum, Geological Series 2:229-247.
Here is the wonderful Brachiosaurus altithorax mount in its original location, in the main hall of the Field Museum in Chicago. (Click through for full resolution.)
I scanned this from Don Glut’s Dinosaurs: The Encyclopedia, page 215. There must be better quality versions somewhere, because this is one of the Field Museum’s own photos — negative #GN 86962 — but I can’t find it in their singularly unhelpful online photo archive.
I’m posting it because there’s an astonishing lack photos of this mount on the Internet. As I noted last time, I was only able to find this striking image:
The Brachiosaurus mount in its original position in the main hall of the Field Museum. I can’t find a higher resolution version of this photo — can anyone help?
at the miserably low resolution shown here (358×248). More generally, almost every photo of a mounted Brachiosaurus out there seems to be from either the picnic area outside the museum, or O’Hare Airport. If anyone’s able to find decent-resolution examples of this skeleton indoors, please do drop the links into a comment.
I mentioned this to Matt, and he commented:
I think that the mount got moved outside just a bare handful of years before digital cameras went from rare to ubiquitous. If the move had happened even five years later, I’ll bet there would be loads of photos of the old mount.
I’m sure he’s right. But someone must have half-decent photos from back then?
Seriously — is this tiny photo the best photographic record we have?
Of course, the real question is: why did they shove the Brachiosaurus outside? It was mounted in 1994, and taken down again in 1999, so this marvellous mount — by any objective standard the single most awesome exhibit in the museum’s history — was only actually in residence for five paltry years.
The standard explanation is that it was removed “to make space for” Sue, the vulgar overstudied theropod. But a glance at the photo above shows that there was plenty of space to put in half a dozen T. rexes without needing to move the brachiosaur. I can only assume that someone realised having a brachiosaur next door would make Sue look feeble. It’s a tragedy.
Update
Thanks to Dean for finding this one: small, but beautiful.
References
Glut, Donald F. 1997. Dinosaurs: The Encyclopedia. McFarland & Company, Inc., Jefferson, North Carolina. 1076 pages.
After P.A.S.T president Gilles Danis commented on our post about the Chicago airport Brachiosaurus mount, I got into an interesting email conversation with him. Here, posted with his kind permission and only lightly edited, are his thoughts on the Brachiosaurus mount.
Brachiosaurus mount at Chicago O’Hare Airport, terminal one. Pelvis in ventral view, anterior to the left.
Gilles writes:
The story of this mount (s) is chequered. The casts of real material include the sacrum, the caudal, a number of dorsals, some rib fragments, one femur, a very badly eroded humerus and a coracoid. [Update: also the right ilium, as Gilles subsequently confirmed by email.]
On the mount that was in the museum and later was moved to the airport, we had a peculiar situation to deal with. Because museums like to have people walking under the rib cage of high sauropods, this becomes a safety hazard for two reasons. The first is that it cannot be allowed to fall on the people (obviously) and even though the cast was of light plastic, the engineers insisted in overbuilding the support (namely the legs and arms). Also because while in the Field Museum, it stood in the path of a fire exit, we had to have a certain amount of distance between the front and hind limbs (I forget the exact measurement). The only way that we could achieve that was to add two vertebrae for a total of 12 dorsals. We chose to duplicate two of real vertebrae at the lower end of the dorsal section.
The Brachiosaurus mount in its original position in the main hall of the Field Museum. I can’t find a higher resolution version of this photo — can anyone help?
The funny thing is only one person figured that one out and that was Bill Simpson the collections manager. Also to support this structure, we were asked to used way oversized steel in the limbs which meant that we had to “inflate” the real humerus and femur to accommodate the material. This is why the cast is so bad; it is half stuffing.
It is interested to see how a lie perpetuates itself. The following year, the Hayashibara museum ordered a mount of the same skeleton and they were very interested in getting the distance between the feet and manus. So we, again, had to make a Brachiosaurus limoensis.
Not satisfied with this silly situation, Disney came to us in 1996 and ordered that very same skeleton again with the stretch limo factor for another dinosaur that you walk under for the Wild Animal Kingdom park in Orlando. Up to that point, only Bill Simpson had realized the error. But I had just had it up to there with these stretch dinosaurs and revealed the problem. After that, in 1999, we replaced the skeleton in Stanley Field Hall with one on the terrace to make room for Sue the T. rex. On this Brachiosaurus, we have the normal 10 dorsals. The last Brachiosaurus we mounted is in the North American Museum of Ancient Life (N.A.M.A.L.) at Thanksgiving Point, Lehi, Utah, again a normal skeleton.
If this was not enough we restored Seismosaurus halli (now Diplodocus hallorum). This project was sponsored by a Japanese company who was to get the first mount. They took Gillette’s publication and read that the skeleton would have been 150′ long or 50 meters. We soon realized that there was a mistake, that the tail was not missing a huge section but had simply drifted away from the sacrum and the skeleton would not be even close to the predicted length. The Japanese would have none of it. After months of negotiations, we arrived at a compromise and we made the skeleton 40 meters long, 133’+ by adding some whiplash vertebrae until it was that long. By then I had had enough and threw in the towel but not before mounting another Seismosaurus for the museum is Albuquerque which is correct.
As for the Berlin brachiosaur: I spent some time in Berlin measuring, photographing and drawing (Donna Sloan did the drawing) the original material there, but they would not allow us to mould it. What I found interesting is that in 1992 when I was there, most of the skeleton of the mount was not original but it was not cast either. It was sculpted wood.
I have many more tails (pun, ha,ha) about sauropods. I should write them down sometime.
Many thanks to Gilles for allowing us to reproduce this important information.
Gilles’ list of real material that was cast for the mount includes very nearly all of the holotype FMNH P25107 — assuming that “a number of dorsals” means seven, the number that Riggs excavated and had prepared. The only fossil elements not apparently appearing are the fragmentary first caudal and the right ilium. But it seems to me from some of my photos of the airport mount (see the image at the top) that a cast of the right ilium was used. [Update: yes, Gilles confirmed by email that the right ilium was indeed cast from real material.]
Regarding the number of dorsal vertebrae: it may have been circumstances that forced P.A.S.T to give the mount 12 dorsals, but Migeod’s pre-description of the NHM’s Tendaguru brachiosaur gives good reason to think this is likely the correct count.
Similarly, although the torso was therefore longer than Gilles had intended, it might have ended up correct, as careful comparison of the lengths of the Brachiosaurus and Giraffatitan dorsals suggests that the torso of the former was about 23% longer.
To my shame, I’d not realised that the Brachiosaurus at the airport has two more dorsals than the one in the Field Museum picnic area, despite Matt having posted a ventral-view photo of the airport mount that clearly shows the twelve dorsals and a lateral-view photo of the museum mount that clearly shows ten.
When Gilles says “most of the skeleton of the [Berlin] mount was not original but it was not cast either”, I assume he’s referring to the presacral vertebrae, which as Janensch explained in his 1950 paper about that mount were too heavy and fragile to mount. The sculptures in Janensch’s mount were not particularly good, but they have been replaced by much better ones in the remount.
Sauropod Vertebra Picture of the Week 