An important paper is out today: Carpenter (2018) names Maraapunisaurus, a new genus to contain the species Amphicoelias fragillimus, on the basis that it’s actually a rebbachisaurid rather than being closely related to the type species Amphicoelias altus.

Carpenter 2018: Figure 5. Comparison of the neural spine of Maraapunisaurus fragillimus restored as a rebbachisaurid (A), and the dorsal vertebrae of Rebbachisaurus garasbae (B), and Histriasaurus boscarollii (C). Increments on scale bars = 10 cm.

And it’s a compelling idea, as the illustration above shows. The specimen (AMNH FR 5777) has the distinctive dorsolaterally inclined lateral processes of a rebbachisaur, as implied by the inclined laminae meeting at the base of the SPOLs, and famously has the very excavated and highly laminar structure found in rebbachisaurs — hence the species name fragillimus.

Ken’s paper gives us more historical detail than we’ve ever had before on this enigmatic and controversial specimen, including extensive background to the excavations. The basics of that history will be familiar to long-time readers, but in a nutshell, E. D. Cope excavated the partial neural arch of single stupendous dorsal vertebra, very briefly described it and illustrated it (Cope 1878), and then … somehow lost it. No-one knows how or where it went missing, though Carpenter offers some informed speculation. Most likely, given the primitive stabilisation methods of the day, it simply crumbled to dust on the journey east.

Carpenter 2018: Frontispiece. E. D. Cope, the discoverer of AMNH FR 5777, drawn to scale with the specimen itself.

Cope himself referred the vertebra to his own existing sauropod genus Amphicoelias — basically because that was the only diplodocoid he’d named — and there it has stayed, more or less unchallenged ever since. Because everyone knows Amphicoelias (based on the type species A. altus) is sort of like Diplodocus(*), everyone who’s tried to reconstruct the size of the AMNH FR 5777 animal has done so by analogy with Diplodocus — including Carpenter himself in 2006, Woodruff and Foster (2014) and of course my own blog-post (Taylor 2010).

(*) Actually, it’s not; but that’s been conventional wisdom.

Ken argues, convincingly to my mind, that Woodruff and Foster (2014) were mistaken in attributing the great size of the specimen to a typo in Cope’s description, and that it really was as big as described. And he argues for a rebbachisaurid identity based on the fragility of the construction, the lamination of the neural spine, the extensive pneumaticity, the sheetlike SDL, the height of the postzygapophyses above the centrum, the dorsolateral orientation of the transverse processes, and other features of the laminae. Again, I find this persuasive (and said so in my peer-review of the manuscript).

Carpenter 2018: Figure 3. Drawing made by E.D. Cope of the holotype of Maraapunisaurus fragillimus (Cope, 1878f) with parts labeled. “Pneumatic chambers*” indicate the pneumatic cavities dorsolateral of the neural canal, a feature also seen in several rebbachisaurids. Terminology from Wilson (1999, 2011) and Wilson and others (2011).

If AMNH FR 5777 is indeed a rebbachisaur, then it can’t be a species of Amphicoelias, whose type species is not part of that clade. Accordingly, Ken gives it a new generic name in this paper, Maraapunisaurus, meaning “huge reptile” based on Maraapuni, the Southern Ute for “huge” — a name arrived at in consultation with the Southern Ute Cultural Department, Ignacio, Colorado.

How surprising is this?

On one level, not very: Amphicoelias is generally thought to be a basal diplodocoid, and Rebbachisauridae was the first major clade to diverge within Diplodocoidae. In fact, if Maraapunisaurus is basal within Rebbachisauridae, it may be only a few nodes away from where everyone previously assumed it sat.

On the other hand, a Morrison Formation rebbachisaurid would be a big deal for two reasons. First, because it would be the only known North American rebbachisaur — all the others we know are from South America, Africa and Europe. And second, because it would be, by some ten million years, the oldest known rebbachisaur — irritatingly, knocking out my own baby Xenoposeidon (Taylor 2018), but that can’t be helped.

Finally, what would this new identity mean for AMNH FR 5777’s size?

Carpenter 2018: Figure 7. Body comparisons of Maraapunisaurus as a 30.3-m-long rebbachisaurid (green) compared with previous version as a 58-m-long diplodocid (black). Lines within the silhouettes approximate the distal end of the diapophyses (i.e., top of the ribcage). Rebbachisaurid version based on Limaysaurus by Paul (2016), with outline of dorsal based on Rebbachisaurus; diplodocid version modified from Carpenter (2006).

Because dorsal vertebrae in rebbachisaurids are proportionally taller than in diplodocids, the length reconstructed from a given dorsal height is much less for rebbachisaurs: so much so that Ken brings in the new version, based on the well-represented rebbachisaur Limaysaurus tessonei, at a mere 30.3 m, only a little over half of the 58 m he previously calculated for a diplodocine version. That’s disappointing for those of us who like our sauropods stupidly huge. But the good news is, it makes virtually no difference to the height of the animal, which remains prodigious — 8 m at the hips, twice the height of a giraffe’s raised head. So not wholly contemptible.

Exciting times!

References

 

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As Matt recently noted, we both have a ton of photos from various expeditions that we’ve never got around to posting — not to mention a ton of specimens that we’ve seen but never got around to working on. Here is one of the most exciting:

As you can see, this is a massive cervical vertebra from a sauropod, probably a brachiosaurid, eroding right out of the ground. It’s in an undisclosed location in the Arches National Park, which we visited in May 2016. The neural arch is in amazingly good shape, though the end of the right prezygapophysis has broken off and been displaced slightly upwards. The postzygapophysesal facet is difficult to make out. Here’s a rough-and-ready interpretive drawing to get you oriented, with the completely missing parts speculatively sketched in light grey. (We don’t know how much more of this vertebra might be preserved underground.)

Apart from its size, the most striking thing about this vertebra is how very pneumatic it is — corroborating the long-standing hypothesis that pneumaticity tends to be positively allometric. If you compare with the much-loved 8th cervical vertebra of the Giraffatitan brancai paralectotype MB.R.2181 (formerly HMN SII), you can see similar “sculpted” features on the arch of that vertebra, but they are much less developed and ramified:

(This photo is in of course in left dorsolateral view, whereas the aspect of the Arches vertebra available to us is right lateral, and slightly ventral of true lateral.)

How big is the Arches vertebra? Stupidly, we didn’t have measuring equipment with us when we were visiting the park, so we don’t have an exact figure. But we can get some idea by extrapolating from the photo above. The stretched-out arm-span of an adult man is close to his height. I’m 1.8 m tall, so allowing for the downward slope of my arms, we might guess that the fingertip-to-fingertip measurement is about 1.7 m. If that’s right, measuring off the photo, the preserved portion of the vertebra is nearly twice that, at 3.3 m — and the complete length must have been somewhat longer, as the back end of the centrum is completely missing. Something in the region of 3.6 m might not be too far out. But as always, note that these are extremely speculative figures based on multiple layers of approximation.

We really need to get back out there, measure that thing properly, and of course try to find a way to have it excavated.

“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?

Here is a vertebra that Matt and I saw on our recent travels through Utah:

IMG_2530

IMG_2542

I will explain in a subsequent post where we saw it, who gave us access, where and when it is from, and so on.

For now, I want people’s gut reactions: what is it?

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!

Who owns journals?

September 14, 2013

Suppose you’re working on a Wealden sauropod — for example, the disturbingly Camarasaurus-like isolated dorsal vertebra NHM R2523 — and for some reason you desperately want to publish your work in Cretaceous Research.

bmnh-r2523-orthogonal

But it’s published by Elsevier, which means that if you’re committed to open access, you have to find an exorbitant $3300 for the APC. Since Elsevier’s profit margin is 37.3%, you know that $1230.90 of your APC is going to be sliced right off the top. I’ve heard it said (but don’t have a reference for this) that barrier-based publishers spend something like 40% of their costs on marketing subscriptions. So there goes another $827.64. And because legacy publishers have to spend a fortune on paywalls, authentication systems, lawyers, spin-doctors, lobbyists and the like, that could well account for, say, half of the remainder. If that’s correct, then only $620.73 of your APC — 19% of what you give them — is actually paying for publishing services such as copy-editing, typesetting, Web hosting and archiving.

You could be forgiven for thinking that’s not the best way to spend your $3300.

it would of course be much cheaper to publish in PLOS ONE, or PeerJ, or eLife, or F1000 Research, or one of the relevant BMC journals. But let’s suppose that your heart is set on Cretaceous Research.

I don’t know how common it is for people to find themselves in this situation, but I’m guessing it crops up more often than somewhat. Often enough, maybe, that the editors wish that the journal they run was published by someone other than Elsevier.

So my question is this: who “owns” journals? For example, we know JVP could move away from T&F if they wanted — at least, when its four-year contract expires — but could Cretaceous Research move from Elsevier? Do the editorial board “own” it? Or does Elsevier? If the CR editors hypothetically wanted to keep running their journal but as (say) an open access Ubiquity Press journal with a £250 APC, would they be forced to start The New Journal of Cretaceous Research, leaving the old one to wither with no editors?

And just to be clear: this isn’t a question about Cretaceous Research, Elsevier and Ubiquity. They’re just examples. It’s about the broader problem of who controls what journals, and what the people who actually run those journals can do about it.

From the collections of the American Museum of Natural History, I give you the sacrum and fused ilia of “Apatosaurusminimus AMNH 675, as correctly identified by Steve P in a comment to the previous post:

"Apatosaurus" minimus sacrum with fused ilium, right lateral view

As Steve P rightly pointed out, AMNH 675 was designated as Brontosaurus sp. by Osborn (1904), and made the type of Apatosaurus minimus by Mook (1917).

It’s been known for some time that whatever this is, it’s not Apatosaurus — see for example McIntosh (1990a:398), McIntosh (1990b:59) and Upchurch et al. (2004:298). But what actually is it? Well, at the moment, no-one knows. Matt and I now have a manuscript in prep that we hope will somewhat elucidate this question. More to come on this specimen, most likely.

References

McIntosh, John S. 1990a. Sauropoda. In The Dinosauria, pp. 345–401. Berkeley and Los Angeles: University of California Press.

McIntosh, John S. 1990b. Species Determination in Sauropod Dinosaurs with Tentative Suggestions for the Their Classification. In Dinosaur Systematics: Approaches and Perspectives, pp. 53–69. Cambridge: Cambridge University Press.

Mook, Charles C. 1917. Criteria for the determination of species in the Sauropoda, with description of a new species of Apatosaurus. Bulletin of the American Museum of Natural History 38:355-360.

Osborn, Henry F. 1904. Manus, sacrum, and caudals of Sauropoda. Bulletin of the American Museum of Natural History 20:181-190.

Upchurch, Paul, Paul M Barrett, and Peter Dodson. 2004. Sauropoda” In The Dinosauria, 2nd Edition, pp. 259–322. Berkeley and Los Angeles: University of California Press.