“Biconcavoposeidon”

August 15, 2017

Here is a fascinating sequence of five consecutive posterior dorsal vertebra — AMNH FARB 291 from the”Big Bone Room” at the AMNH:

AMNH FARB 291, five consecutive posterior dorsal vertebrae of a probably brachiosaurid sauropod, in right lateral view. The vertebrae are embedded in a plaster block, which has been desaturated in this image.

Matt and I first saw this specimen back in February 2009, when we were mostly there to look at Apatosarusminimus (and then again in 2012). As soon as our eyes lit on it, we couldn’t help but be captivated by its bizarre biconcave centra. We immediately started flippantly referring to it as “Biconcavoposeidon” — the ugliest name we could come up with — and in our subsequent discussions the name has stuck (often abbreviated to “BCP”).

  • Taxonomic note: for avoidance of doubt, “Biconcavoposeidon” is not and will never be a formal taxonomic name, only an informal specimen nickname. If at some future point we conclude that this specimen represents a new taxon, and name it, we will definitely not use the name “Biconcavoposeidon”. If you ever use the name, please do not set it in italics.

As you can see in this front view, the specimen is sheared: the upper part of the vertebrae have been displaced to their left (which is the right as we see it in this image):

AMNH FARB 291, most anterior of five consecutive posterior dorsal vertebrae of a probably brachiosaurid sauropod, in anterior view.

Apart from the shearing, though, and the truncation of the neural spines shortly above the transverse processes, the specimen is in pretty good nick. Crucially, it’s not been “restored” in plaster to conceal what is and is not real bone — unlike many specimens of that era. It came out of the Bone Cabin quarry in 1898, back when scientific information was routinely discarded in order to obtain a more beautiful-looking specimen.

This is the specimen that I’ll be presenting at SVPCA this year — though only as a poster, unfortunately: there’s no talk for me, Matt or Darren this year. We’ve posted our abstract (including the illustration above) to the nascent PeerJ collection for SVPCA 2017, and we’re looking forward to seeing more of the materials from that conference — abstracts, then manuscripts, then papers — appearing in the collection.

So far as we know, there’s no other sauropod specimen with biconcave posterior dorsal vertebrae. (And, no, Amphicoelias is not an exception, despite its name.) But have we missed any?

Turns out that if Mike and I don’t post about sauropods for a while, people start doing it for us! This very interesting project by Tom Johnson of Loveland, Colorado, first came to my attention when Tom emailed Mark Hallett about it and Mark kindly passed it on to me. I got in touch with Tom and asked if he’d be interested in writing it up for SV-POW!, and here it is. Many thanks to Tom for his willingness to share his work with us. Enjoy! – Matt Wedel

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The sauropod formerly known as Apatosaurus in the American Museum of Natural History was the first permanently mounted sauropod dinosaur in the world, and for many years, the most famous (Brinkman 2010). The greater part of the skeleton consists of the specimen AMNH 460 from the Nine Mile Crossing Quarry north of Como Bluff, Wyoming, supplemented with bones from other AMNH specimens from Como Bluff, Bone Cabin Quarry, and with plaster casts of the forelimbs of the holotype specimen of Brontosaurus excelsus (YPM 1980) at the Yale Peabody Museum.

A herd of Brontosaurus skeleton models parading before four box covers issued between the 1950s and 1990s.

Like many aging boomer dinophiles, my dinosaur epiphany was the result of books, movies, and toys available in the 1950s, but especially a series of plastic model dinosaur skeletons that appeared around 1958. The Brontosaurus was my personal favorite, and, like the Tyrannosaurus and Stegosaurus models in the series, was very obviously based on the AMNH mount. The models were reissued at least three times over the years and can still be found either “mint in box” or more often in various stages of completion.

Apatosaurus lousiae 1/12 scale skeleton, modelled by Phil Platt, assembled and photographed by Brant Bassam. Image courtesy of BrantWorks.com.

The crème de la crème today, of course, is the 1:12 scale Apatosaurus skeleton model by Phil Platt, available from Gaston Design in Fruita, Colorado. A particularly nice example is the one completed and mounted by Brant Bassam of BrantWorks. The Platt skeleton is a replica in the true sense of the word. The plastic models are pretty crude in comparison, as cool as they appeared to us as kids.

I was interested in skeletal illustrations I have seen of Tyrannosaurus rex, which compare the completeness of various specimens by showing the actual bones included by coloring them red. A 2005 study of Apatosaurus by Upchurch et. al. examined eleven of the most complete Apatosaurus individuals, and I was interested to see the actual bones known for each specimen. Using published descriptions, red markers, and copies of a skeletal silhouette of Apatosaurus (permission obtained from the artist), I prepared a comparison of the most completely known Apatosaurus specimens. It was clear, of course, that Apatosaurus louisae (CM 3018) is the most complete specimen of the Apatosaurus/Brontosaurus group. But it also was apparent that old AMNH 460 included a substantial portion of the skeleton, even if it is a composite.

I grabbed some additional markers and, using the illustration of the mount in William Diller Matthew’s popular book Dinosaurs (Matthew 1915, fig. 20, which I trust is in the public domain by now), I color-coded the bones according to the composition as listed in Matthew’s (1905) article:

  • AMNH 460, Nine-Mile Crossing Quarry: 5th, 6th, 8th to 13th cervical vertebrae; 1st to 9th dorsal; 3rd to 19th caudal; all ribs; both coracoids; “parts of” sacrum and ilia; both ischia and pubes; left femur and astragalus; and “part of” the left fibula. RED
  • AMNH 222, Como Bluff: right scapula, 10th dorsal vertebra, right femur and tibia. GREEN
    (Visitors to AMNH: you can see the rest of AMNH 222 under the feet of the hunched-over Allosaurus)
  • AMNH 339, Bone Cabin Quarry: 20th to 40th caudal vertebrae. LIGHT BLUE
  • AMNH 592, Bone Cabin Quarry: metatarsals of the right hind foot. VIOLET
  • YPM 1980, Como Bluff: left scapula, forelimb long bones (casts). YELLOW
  • The remaining parts of the skeleton are either modeled in plaster or are unspecified (“a few toe bones”). BLACK

It occurred to me that I might have sufficient spare parts of old ITC and Glencoe Brontosaurus models to create a three-dimensional version. I did, and painting prior to assembly definitely made the job easier.

There are obviously limitations to using Matthew’s (1915) reconstruction (e.g., only 13 cervicals) and the model (12 cervicals). It is also not clear from Matthew’s description how much of the sacrum and ilia were restored. Nevertheless, the painted model does provide a colorful, if crude, visualization of the composition of the composite.

Here are some more photos of the finished product:

A view from the front of the model, compared with a historical AMNH photo of the forelimbs and pelvic girdle.

Long considered a specimen of Brontosaurus excelsus or Apatosaurus excelsus, AMNH 460 was referred to Apatosaurus ajax by Upchurch et. al. in 2005. In the most comprehensive analysis of diplodocid phylogeny to date, Tschopp et. al. (2015) found AMNH 460 to be an “indeterminate apatosaurine” pending a “detailed analysis of the specimen.” What to call it? Oh, yeah, that’s been covered in another post!

This is a nostalgia shot for the old brontophiles. Notice that the Triceratops is entering the lake for a swim!

Tom Johnson with the mounted skeleton of Amphicyon, a Miocene “bear-dog”,
in the Raymond Alf Museum of Paleontology in Claremont, California.

References

  • Brinkman , Paul D. (2010). The Second Jurassic Dinosaur Rush, University of Chicago Press, 2010.
  • Matthew, William Diller, (1905). “The Mounted Skeleton of Brontosaurus,” The American Museum Journal, Vol. V, No. 2, April.
  • Matthew, W.D. (1915). Dinosaurs, With Special Reference to the American Museum Collections, American Museum of Natural History, New York.
  • Tschopp, Emanuel, Octávio Mateus, and Roger Benson. (2015). “A Specimen-Level Phylogenetic Analysis and Taxonomic Revision of Diplodocidae (Dinosauria, Sauropoda).” Ed. Andrew Farke. PeerJ 3 (2015): e857.
  • Upchurch, P., Tomida, Y., Barrett, P.M. (2005). “A new specimen of Apatosaurus ajax (Sauropoda: Diplodocidae) from the Morrison Formation (Upper Jurassic) of Wyoming, USA”. National Science Museum Monographs (Tokyo) 26 (118): 1–156.

Prologue

Back when I started writing about issues in scholarly publishing, I would sometimes write about the distinction between for-profit (bad) and non-profit (good) publishers. While I still recognise this as an issue, thinking it through over the last few years has made it clear that this distinction is largely orthogonal to the one that really matters — which is between open and non-open publishers.

In fact, all four quadrants exist:

 For-profit  Non-profit
 Open  PeerJ  PLOS
 Non-Open  Elsevier  ACS

ACS may be a 501(c)(3) nonprofit organization, and PeerJ may be a private company primarily owned by two individuals — but it’s PeerJ that’s pushing openness forward, and ACS doing quite the opposite.

Logue

img_4496

Beautifully preserved cervical vertebra of Barosaurus in the prep. lab at the North American Museum of Natural Life (NAML).

I’ve found myself thinking about this recently for two reasons.

The first is that, like anyone who works on sauropods, I’ve had involvement with specimens at the Sauriermuseum Aathal (SMA), a privately owned museum in Switzerland that holds some astonishingly beautiful and complete specimens, including the Kaatedocus holotype, SMA 0009. In particular, I’ve been invited a few times to peer-review manuscripts describing SMA specimens, and I’ve always felt conflicted about this because of the SVP’s strong position on privately held specimens.

The second thing that’s pushed me to rethink the private-public distinction has been working on Barosaurus. Our experiences with specimens have been varied. Yale University was very helpful when we went to see the holotype YPM 429, and BYU really couldn’t have done more for us on our recent visit. This is what we would hope for, of course. But what we didn’t particularly anticipate is how generous and helpful the people at the commercial fossil hunters Western Paleo Labs would be. When, visiting the North American Museum of Ancient Life, we gazed in awe through their prep. lab window at their several gorgeous Barosaurus cervicals (see photo above), they invited us in to play with them. (The vertebrae, not the people.)

And that made me think about our much less satisfactory experience trying to photograph the presacrals of AMNH 6341 at the American Museum of Natural History — they are entombed in a glass case surmounted by a not-really-transparent walkway:

amnh-presacrals

Which meant that, when trying to obtain dorsal-view photographs, I had to use this technique:

amnh-photography

With results like these:

amnh-dorsal-view

Now I want to be clear that everyone we dealt with at the AMNH was as helpful as they could be. No-one that we met there was in any way obstructive. Yet the fact remains, the crucially important presacral verterbrae of the most widely recognised Barosaurus in the world were essentially impossible to study.

Worse: papers that have been published about those specimens are now essentially irreproducible, because the specimens are not really available for re-study — much as though they’d been sold to Nicolas Cage to display over his mantelpiece.

Whereas the Barosaurus vertebrae at Western Paleo Labs do seem to be available for study.

Hmm.

Just as we were mistaken in focussing primarily on the for-profit/non-profit distinction between publishers when what we really cared about was the open/non-open distinction, could it be that we’ve been misfocussing on the public/private ownership distinction when what we really care about is availability of specimens?

Is there a way to be confident about which museums will and will not always make specifimens available for study? Here’s where my knowledge cuts out, but one would think this would be the key element in museum certification. But then no doubt museum certification is done differently in different jurisdictions. Knowing that a German museum is accredited may tell you something completely different from knowing that an American museum is accredited.

So perhaps what we need is some globally recognised statement that any museum in the world can sign up to: formally committing to keep its specimens available to researchers; and comitting never to sell them to any party that has not also signed up to the statement.

Epilogue

It’s worth noting the Sauriermuseum Aathal seems, as far as I’ve ever heard, to have conducted itself in every way as we would wish. They seem pretty unambiguously to be among the good guys. More: they seem to have unilaterally done more or less what I advocated above: their website declares:

Declaration Concern: Holotypes of the fossil-collection of the Sauriermuseum Aathal.

The Sauriermuseum Aathal, Switzerland (SMA), is being recognized more and more as valuable scientific institution. We hereby state publicly the SMA policy concerning holotype specimens. We recognize the importance of these reference specimens for science, and strongly agree that they have to be available for science in perpetuity. Therefore, we declare that all holotypes present at the Sauriermuseum Aathal, Switzerland (and all new holotypes that will be described in future), will always be publicly accessible to all bona fide researchers, and will never be allowed to be sold to any private collection.

Are they one step ahead of us? And if so, should we cast off our reservations about publishing on their specimens?

 

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:

diplodocus-sacrum-composite

(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):

img_4853-img_4886-v3-sm-sacrum

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.

References

  • 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.

 

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:

IT SHALL BE SO!

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.

Onwards!

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.

References

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.

AMNH 460 left anterolateral view

Apatosaurines on the brain right now.

I’ve been thinking about the question raised by Jerry Alpern, a volunteer tour guide at the AMNH, regarding the recent Tschopp et al. (2015) diplodocid phylogeny. Namely, if AMNH 460 is now an indeterminate apatosaurine, pending further study, what should the museum and its docents tell the public about it?

Geez, Apatosaurus, it’s not like we’re married!

I think it’s a genuinely hard problem because scientific and lay perspectives on facts and hypotheses often differ. If I say, “This animal is Apatosaurus“, that’s a fact if I’m talking about YPM 1860, the genoholotype of Apatosaurus ajax; it would continue to be a fact even if Apatosaurus was sunk into another genus (as Brontosaurus was for so long). We might call that specimen something else, but there would always be a footnote pointing out that it was still the holotype of A. ajax, even if the A. part was at least temporarily defunct – the scientific equivalent of a maiden name.* For every other specimen in the world, the statement, “This animal is Apatosaurus” is a hypothesis about relatedness, subject to further revision.

* This is going to sound kinda horrible, but when one partner in a marriage takes the other’s surname, that’s a nomenclatural hypothesis about the future of the relationship.

Apatosaurine cervicals are the best cervicals.

Apatosaurine cervicals are the best cervicals.

Fuzzy science

Things that look fairly solid and unchanging from a distance – specifically, from the perspective of the public – often (always?) turn out to be fairly fuzzy or even arbitrary upon closer inspection. Like what is Apatosaurus (beyond the holotype, I mean) – or indeed, what is a planet.** There is no absolute truth to quest for here, only categories and hypotheses that scientists have made up so that we can have constructive conversations about the crazy spectrum of possibilities that nature presents us. We try to ground those categories and hypotheses in evidence, but there will always be edge cases, and words will always break down if you push them too hard. Those of us who work on the ragged frontier of science tend to be fairly comfortable with these inescapable uncertainties, but I can understand why people might get frustrated when they just want to know what the damned dinosaur is called.

** Triton, the largest body orbiting Neptune, is almost certainly a captured Kuiper Belt object, and it’s bigger than Pluto. Moon or planet? Probably best to say a former dwarf planet currently operating as a satellite of Neptune – but that’s a mouthful (and a mindful, if you stop to think about it), not a short, convenient, easily-digestible label. Any short label is going to omit important information. This is related to the problem of paper title length – below some threshold, making something shorter means making it incomplete.

What I would say

I suppose the short version that is most faithful to the Tschopp et al. results is:

This skeleton (AMNH 460) might be Apatosaurus or Brontosaurus or a third, new thing – scientists aren’t sure yet.

A reasonable follow-up sentence – and an answer to the inevitable “Why not?” – would be:

They have to look at 477 anatomical details for lots of skeletons and weigh all the evidence, and that takes time.

Personally, if I was talking to museum visitors I would lean in conspiratorially and say:

If you want to call it Apatosaurus or Brontosaurus, go ahead – those are both ‘live’ hypotheses, and even the world’s experts on this problem can’t tell you that you’re guessing the wrong way – at least not yet.

And if there was a kid in the group, I’d add:

Maybe you’ll be the one to figure it out!

What would you say?

My neck is fat.

My neck is fat.

P.S. I wouldn’t change the signage. It could still turn out to be Apatosaurus, and the Tschopp et al. results do not lend themselves to easy label-ification.

P.P.S. With some modification for taxonomy, all of this applies to the Field Museum diplodocid FMNH P25112 as well.

Reference

Tschopp E, Mateus O, Benson RBJ. (2015) A specimen-level phylogenetic analysis and taxonomic revision of Diplodocidae (Dinosauria, Sauropoda) PeerJ3:e857 https://dx.doi.org/10.7717/peerj.857