Back in 2012, when Matt and I were at the American Museum of Natural History to work on Apatosaurus” minimus, we also photographed some other sacra for comparative purposes. One of them you’ve already seen — that of the Camarasaurus supremus holotype AMNH 5761. Here is another:


(Click through for glorious 3983 x 4488 resolution.)

This is AMNH 3532, a diplodocid sacrum with the left ilium coalesced and the right ilium helpfully missing, so we can see the structure of the sacral ribs. Top row: dorsal view, with anterior to the left; middle row, left to right: anterior, left lateral and posterior views; bottom row: right lateral view.

As a matter of fact, we’ve seen this sacrum before, too, in a photo from Matt’s much earlier AMNH visit. But only from a left dorsolateral perspective.

When we first saw this, it didn’t even occur to us that it could be anything other than good old Diplodocus. And indeed it’s a pretty good match for the same area in the CM 84/94 cast in the Museum für Naturkunde Berlin (this image extracted from Heinrich Mallison’s beautiful giant composite):


And the general narrowness of the AMNH sacrum says Diplodocus to me. But what is that expectation of narrowness based on? When I compared the AMNH specimen with Hatcher’s (1901) ventral-view illustration in his classic Diplodocus monograph, I had second thoughts:

Hatcher (1901: fig. 9). Inferior view of sacrum and ilia of Diplodocus carnegii (No. 94), one tenth natural size; bp, public peduncle; is, ischiadic peduncle; a, anterior end; p, posterior end.

Hatcher (1901: fig. 9). Inferior view of sacrum and ilia of Diplodocus carnegii (No. 94), one tenth natural size; pp, public peduncle; is, ischiadic peduncle; a, anterior end; p, posterior end.

That is a much wider sacrum than I’d expected from Diplodocus.

So what is going on here? Is Diplodocus a fatter-assed beast than I’d realised? I am guessing not, since my expectation of narrowness has been built up across years of looking at (if not necessarily paying much attention to) Diplodocus sacra.

So could it be that CM 94, the referred specimen that Hatcher used to make up some of the missing parts of the CM 84 mount, is not Diplodocus?

Well. That is certainly now how I expected to finish this post. Funny how blogging leads you down unexpected paths. It’s a big part of why I recommend blogging to pretty much everyone. It forces you to think down pathways that you wouldn’t otherwise wander.


  • Hatcher, Jonathan B. 1901. Diplodocus (Marsh): its osteology, taxonomy and probable habits, with a restoration of the skeleton. Memoirs of the Carnegie Museum 1:1-63 and plates I-XIII.


Here at SV-POW! Towers, we’re keenly aware that some of our fans are just here for the hardcore sauropod vertebra action. These folks start to shift in their seats when we put up too many posts in a row on open access or rabbits or…okay, mostly just OA and bunnies. If that’s you – or, heck, even if it isn’t – your good day has come. Saddle up. Let’s ride.

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When Brian Engh and I were at the new Natural History Museum of Utah recently, I spotted this cute little juvenile cervical in one of the display cases.

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According to this sign, it’s UMNH 21054, and it was found by Frank DeCourten and prepared by Virginia Tidwell.


It shares a display case and a sign with what is probably an anterior dorsal, UMNH 21055.


Now, I don’t mean to brag (okay, maybe a little…) but the number of EKNApod* vertebrae is not large and the number of EKNApod vertebrae I’m not intimately familiar with hovers near zero. This thing was ringing bells – I knew I’d seen it before.

* Early Cretaceous North American sauropod

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Here are few more views. Note the light-colored oblong spot on the top of the condyle in the image above – this may be a pneumatic foramen filled with matrix, or a spot where the cortical bone flaked away to reveal one of the internal pneumatic spaces. Also, check out the fragment of extraneous bone (probably cervical rib) stuck sideways across the top of the centrum, just behind the condyle, in the image immediately below. Both of these features will be important later.

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The vert belongs to a juvenile sauropod because the neural arch is missing – it didn’t fuse to the centrum before the animal died. But it was a big baby; the centrum is maybe just a hair under 40 cm in length, meaning that a world-record giraffe might just maybe have a couple of cervicals of the same length. But basal titanosauriforms typically have 12-13 cervicals, not the whimpy 7 that almost all mammals must make do with, and all-stars like Euhelopus can have up to 17.

Also, this was not from the middle of the neck. No way. The parapophyses are huge, and the centrum is pretty stubby compared to Sauroposeidon or YPM 5294, the Sauroposeidonesque cervical from Unit VII of the Cloverly (pic here). My guess is we’re looking at something past the middle of the neck, where the cervicals start to get proportionally shorter (but sometimes max out in absolute length), maybe a C9 or C10. In Giraffatitan brancai HM SII/MB.R.2181, C10 has a centrum length of 100 cm and makes up about 12% of the 8.5-meter neck. Assuming similar proportions here, UMNH  21054 came from the roughly 3-meter neck of a sauropod about the size of a really big draft horse or a really small elephant.

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But enough noodling about the animal’s size. I knew I’d seen this vert before, but where? Thank goodness for comprehensive signage – I knew the material had been discovered by Frank DeCourten and prepped by Virginia Tidwell. At one of the SVP meetings in Denver, at a reception at the Denver museum, Virginia had invited me into the prep lab to see some EKNApod material from the Long Walk Quarry in Utah. The Long Walk Quarry was Frank DeCourten’s baby – he wrote a couple of papers about it (e.g., DeCourten 1991) and included additional information in his book, Dinosaurs of Utah (1998; second edition in 2013). DeCourten had referred the material to Pleurocoelus because that’s what people did with EKNApods back in the 20th century, but I remembered seeing one cervical that, like Sauroposeidon and YPM 5294, was just too long to match any of the Pleurocoelus material. My ‘Museum Photos’ file has a subfolder titled ‘Denver 2004’ – was the mystery vert in there?

2004-11-08 SVP 049

In short, yes. Here’s one of the photos I took back in 1994.

2004-11-08 SVP 050

Here’s another, sans flash this time. Check out the white spot on top of the condyle, the bar of float bone stuck sideways across the centrum just behind the spot, and general pattern of breaks – it’s a perfect match for UMNH 21054. Also note the block number on the pink specimen label at the bottom of the image – LWQ8, for Long Walk Quarry.

Three mysteries remain. One, the signage says the vert is from Carbon County, Utah, but the Long Walk Quarry has always been described as being in Emery County. Just a typo, or is there a story there? Two, how much of the animal (or animals) was excavated and prepped? I saw other vertebrae, both larger and smaller, when I was in Denver back on ’04, and DeCourten figured still others that I haven’t yet seen personally. Finally, is anyone working on it? And if not…[cautiously raises hand].

For other posts on the NHMU public galleries, see:


  • DeCourten, F.L.  1991.  New data on Early Cretaceous dinosaurs from the Long Walk Quarry and tracksite, Emery County, Utah.  In: T.C. Chidsey, Jr. (ed) Geology of East-Central Utah. Utah Geological Association Publication 19: 311-325.
  • DeCourten, F.L. 1998. Dinosaurs of Utah. University of Utah Press, Salt Lake City, 208pp.


Now that, faithful readers, is a monument to evolution and its endless forms most beautiful. I’m talking about the wall of ceratopsian skulls at NHMU, of course, not the back of Brian Engh’s head (bottom center).


If you don’t know them all on sight (yet!), here’s a cheat sheet. I goofed on a couple myself: before I looked at the sheet I figured Coahuilaceratops as Pentaceratops and mistook Kosmoceratops for Vagaceratops. Still, 12 out of 14 isn’t bad for a minor-league ceratopsian scholar such as yours truly.


Here’s the chasmosaurine-centric view from lower right.


And the centrosaurine-centric view from distant left.

The world needs more things like this. Good on ya, NHMU.

For other NHMU posts, see:

Natural History Museum of Utah: Barosaurus


Brian Engh (bottom left, enthusing about the Ceratosaurus just off-screen) and I are recently returned to civilization after a stint of fieldwork in Utah. On the way home, we made a detour to Salt Lake to visit the new Natural History Museum of Utah.


The NHMU is one of the nicest museums I’ve ever had the pleasure of roaming through. They have a ton of stuff on display, including lots of real fossils and quite a few touchable specimens, with an understandably heavy emphasis on Utah’s extensive paleontological record.


The museum is also beautifully laid out – you can walk around almost all of the mounts and see most of them from multiple levels of elevation. The signage hits a new high for being both discreet and informative. Almost everything on display is clearly identified either as a cast or by specimen number (or maybe both), and the real specimens typically list both the discoverer and the preparator. I’ve never seen that before, and I like it a lot.


I suppose I should say a few words about the Barosaurus mount. It’s pretty cool – you can get very close to it, walk all the way around the body, and – crucially for a true sauropod lover – count vertebrae. They gave it 16 cervicals and 9 dorsals, just as hypothesized by McIntosh (2005), and unlike the AMNH Barosaurus, which has the neck cheated out by one extra cervical.

On the left in the photo above is the famous wall of ceratopsian skulls. More about that next time.


McIntosh, J.S. 2005. The genus Barosaurus Marsh (Sauropoda, Diplodocidae); pp. 38-77 in Virginia Tidwell and Ken Carpenter (eds.), Thunder Lizards: the Sauropodomorph Dinosaurs. Indiana University Press, Bloomington, Indiana, 495 pp.

Re-reading an email that Matt sent me back in January, I see this:

One quick point about [an interesting sauropod specimen]. I can envision writing that up as a short descriptive paper, basically to say, “Hey, look at this weird thing we found! Morrison sauropod diversity is still underestimated!” But I honestly doubt that we’ll ever get to it — we have literally years of other, more pressing work in front of us. So maybe we should just do an SV-POW! post about the weirdness of [that specimen], so that the World Will Know.

Although as soon as I write that, I think, “Screw that, I’m going to wait until I’m not busy* and then just take a single week* and rock out a wiper* on it.”

I realize that this way of thinking represents a profound and possibly psychotic break with reality. *Thrice! But it still creeps up on me.

(For anyone not familiar with the the “wiper”, it refers to a short paper of only one or two pages. The etymology is left as an exercise to the reader.)

It’s just amazing how we keep on and on falling for this delusion that we can get a paper out quickly, even when we know perfectly well, going into the project, that it’s not going to work out that way. To pick a recent example, my paper on quantifying the effect of intervertebral cartilage on neutral posture was intended to be literally one page, an addendum to the earlier paper on cartilage: title, one paragraph of intro, diagram, equation, single reference, DONE! Instead, it landed up being 11 pages long with five illustrations and two tables.

I think it’s a reasonable approximation to say that any given project will require about an order of magnitude more work than we expect at the outset.

Even as I write this, the top of my palaeo-work priority list is a paper that I’m working on with Matt and two other colleagues, which he kicked off on 6 May, writing:

I really, really want to kill this off absolutely ASAP. Like, seriously, within a week or two. Is that cool? Is that doable?

To which I idiotically replied:


A month and a bit later, the answers to Matt’s questions are clear. Yes, it’s cool; and no, it’s not doable.

The thing is, I think that’s … kind of OK. The upshot is that we end up writing reasonably substantial papers, which is after all what we’re meant to be trying to do. If the reasonably substantial papers that end up getting written aren’t necessarily the ones we thought they were going to be, well, that’s not a problem. After all, as I’ve noted before, my entire Ph.D dissertation was composed of side-projects, and I never got around to doing the main project. That’s fine.

In 2011, Matt’s tutorial on how to find problems to work on discussed in detail how projects grow and mutate and anastamose. I’m giving up on thinking that this is a bad thing, abandoning the idea that I ought to be in control of my own research program. I’m just going to keep chasing whatever rabbits look good to me at the time, and see what happens.


A couple of months ago, Darren (the silent partner in the SV-POW! organisation) tweeted this photo …


… describing it as “Skull of the Morrison Formation Brachiosaurus at Denver Museum of Nature & Science”.


As Darren knows well (but didn’t have have space to explain in the tweet), it’s not quite as simple as that. What follows is adapted from Taylor 2009:789.

In 1883, a large sauropod skull (81 cm in length) was found in Felch Quarry 1, Garden Park, Colorado. It was shipped to O. C. Marsh in Yale that year and an illustration of the skull was used in his second attempt at reconstructing the skeleton of Brontosaurus (Marsh, 1891: plate 16).

Marsh's second attempt at reconstructing the skeleton of Brontosaurus, based primary on the holotype YPM 1980, using a skull based on the Felch Quarry specimen. From Marsh (1891:plate XVI)

Marsh’s second attempt at reconstructing the skeleton of Brontosaurus, based primary on the holotype YPM 1980, using a skull based on the Felch Quarry specimen. From Marsh (1891:plate XVI)

And here’s that skull in close-up:


This is often described as a “Camarasaurus-type” skull, but it’s not, really. It’s too long and low, and not stupid and ugly enough, to be Camarasaurus.

As we described in a previous post, this skull was also apparently the inspiration for the horrible, horrible sculpted skull that was originally used on the mounted Brontosaurus. (And let me reiterate my praise of the Yale museum for displaying this important historic object in their gallery instead of hiding it away.)

Anyway, the Felch Quarry skull was subsequently transferred to the National Museum of Natural History, where it was accessioned as USNM 5730. McIntosh and Berman (1975:195-198) recognized that whatever the skull was, it wasn’t Brontosaurus, but chickened out a bit by describing it as being “of the general Camarasaurus type” (p. 196). But McIntosh subsequently identified the skull tentatively as Brachiosaurus (Carpenter and Tidwell, 1998:70) and it was later described by Carpenter and Tidwell (1998), who considered it intermediate between the skulls of Camarasaurus and Giraffatitan, and referred it to Brachiosaurus sp.

The skull may be that of Brachiosaurus altithorax, but this is currently impossible to test due to the lack of comparable parts. Near this skull was a 99 cm cervical vertebra, probably of Brachiosaurus, but this was destroyed during attempts to collect it (McIntosh and Berman, 1975:196). Shame there are no photos.


  • Carpenter, Kenneth, and Virginia Tidwell. 1998. Preliminary description of a Brachiosaurus skull from Felch Quarry 1, Garden Park, Colorado. Modern Geology 23:69-84.
  • Marsh, Othniel Charles. 1891. Restoration of Triceratops. American Journal of Science, Series 3, 41:339-342.
  • McIntosh, John S., and David S. Berman. 1975. Description of the palate and lower jaw of the sauropod dinosaur Diplodocus (Reptilia: Saurischia) with remarks on the nature of the skull of Apatosaurus. Journal of Paleontology 49:187-199.
  • Taylor, Michael P. 2009. A re-evaluation of Brachiosaurus altithorax Riggs 1903 (Dinosauria, Sauropoda) and its generic separation from Giraffatitan brancai (Janensch 1914). Journal of Vertebrate Paleontology 29(3):787-806.

AMNH 460 skeleton model 2

In a recent post I showed some photos of the mounted apatosaurine at the American Museum of Natural History in New York, AMNH 460, which Tschopp et al. (2015) regarded as an indeterminate apatosaurine pending further study.

A lot of museums whose collections and exhibits go back to the late 19th and early 20th centuries have scale model skeletons and sculptures that were used to guide exhibit design. I have always been fascinated by these models, partly because they’re windows into another era of scientific research and science communication, and partly because they’re just cool – basically the world’s best dinosaur toys – and I covet them. In my experience, it is very, very common to find these treasures of history buried in collections, stuck up on top of specimen cabinets, or otherwise relegated to some out-of-the-way corner where they won’t be in the way. I know that exhibit space is always limited, and these old models often reflect ideas about anatomy, posture, or behavior that we now know to be mistaken. But I am always secretly thrilled when I see these old models still on exhibit.

AMNH T rex skeleton model

The AMNH has a bunch of these things, because Henry Fairfield Osborn was crazy about ’em. He not only used 2D skeletal reconstructions and 3D model skeletons to guide exhibit design, he published on them – see for example his 1898 paper on models of extinct vertebrates, his 1913 paper on skeleton reconstructions of Tyrannosaurus, and his 1919 paper with Charles Mook on reconstructing Camarasaurus. That genre of scientific paper seems to have disappeared. I wonder if the time is right for a resurgence.

So in a glass case at the feet of AMNH 460 is a model – I’d guess about 1/12 or 1/15 scale – of that very skeleton. You can tell that it’s a model of that particular skeleton and not just some average apatosaur by looking carefully at the vertebrae. Apatosaurines weren’t all stamped from quite the same mold and the individual peculiarities of AMNH 460 are captured in the model. It’s an amazing piece of work.

AMNH 460 skeleton model

The only bad thing about it is that – like almost everything behind glass at the AMNH – it’s very difficult to photograph without getting a recursive hell of reflections. But at least it’s out where people can see and marvel at it.

Oh, and those are the cervical vertebrae of Barosaurus behind it – Mike and I spent more time trying to look and shoot past this model than we did looking at it. But that’s not the model’s fault, those Barosaurus cervicals are just ridiculously inaccessible.

So, memo to museums: at least some of us out here are nuts about your old dinosaur models, and where there’s room to put them on exhibit, they make us happy. They also give us views of the skeletons that we can’t get otherwise, so they serve a useful education and scientific purpose. More, please.


Osborn, H. F. (1898). Models of extinct vertebrates. Science, New Series, 7(192): 841-845.

Osborn, H.F. (1913). Tyrannosaurus, restoration and model of the skeleton. Bulletin of the American Museum of Natural History, 32: 91-92, plates 4-6.

Osborn, H. F., & Mook, C. C. (1919). Characters and restoration of the sauropod genus Camarasaurus Cope. From type material in the Cope Collection in the American Museum of Natural History. Proceedings of the American Philosophical Society, 58(6): 386-396.


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