May 29, 2013
We jumped the gun a bit in asking How fat was Camarasaurus? a couple of years ago, or indeed How fat was Brontosaurus? last year. As always, we should have started with extant taxa, to get a sense of how to relate bones to live animals — as we did with neck posture.
So here we go. I give you a herd of Indian elephants, Elephas maximus (from here):
You will notice, from this conveniently-close-to-anterior view, that their torsos bulge out sideways, much further than the limbs.
The rib-cage is tiny. It doesn’t even extend as far laterally as the position of the limb bones.
(And lest you think this is an oddity, do go and look at any mounted elephant skeleton of your choice, Indian or African. They’re all like this.)
What’s going on here?
Is Oxford’s elephant skeleton mounted incorrectly? More to the point, are all museums mounting their elephants incorrectly? Do elephants’ ribs project much more laterally in life?
Do elephants have a lot of body mass superficial to the rib-cage? If so, what is that mass? It’s hard to imagine they need a huge amount of muscle mass there, and it can’t be guts. Photos like this one, from the RVC’s televised elephant dissection on Inside Nature’s Giants, suggest the ribs are very close to the body surface:
I’m really not sure how to account for the discrepancy.
Were sauropods similarly much fatter than their mounted skeletons suggest? Either because we’re mounting their skeletons wrongly with the ribs too vertical, or because they had a lot of superficial body mass?
Consider this mounted Camarasaurus skeleton in the Dinosaur Hall at the Arizona Museum of Natural History (photo by N. Neenan Photography, CC-BY-SA):
Compare the breadth of its ribcage with that of the elephant above, and then think about how much body bulk should be added.
This should encourage palaeoartists involved in the All Yesterdays movement to dramatically bulk up at least some of their sauropod restorations.
It should also make us think twice about our mass estimates.
I’ve recently written about my increasing disillusionment with the traditional pre-publication peer-review process [post 1, post 2, post 3]. By coincidence, it was in between writing the second and third in that series of posts that I had another negative peer-review experience — this time from the other side of the fence — which has left me even more ambivalent about the way we do things.
On 17 July I was asked to review a paper for Biology Letters. Having established that it was to be published as open access, I agreed, was sent the manuscript, and two days later sent a response that recommended acceptance after only minor revision. Eleven days later, I was sent a copy of the editor’s decision — a message that included all three reviewers’ comments. I can summarise those reviewers’ comments by directly quoting as follows:
Revewer 1: “It is good to have this data published with good histological images. I have only minor comments – I think the ms should generally be accepted as it is.”
Reviewer 2 (that’s me): “This is a strong paper that brings an important new insight into a long-running palaeobiological issue [...] and should be published in essentially its current form.”
Reviewer 3: “This manuscript reports exciting results regarding sauropod biomechanics [...] The only significant addition I feel necessary is to the concluding paragraph.”
So imagine my surprise when the decision letter said:
I am writing to inform you that your manuscript [...] has been rejected for publication in Biology Letters.
This action has been taken on the advice of referees, who have recommended that substantial revisions are necessary. With this in mind we would like to invite a resubmission, provided the comments of the referees are taken into account. This is not a provisional acceptance.
The resubmission will be treated as a new manuscript.
I can’t begin to imagine how they turned three “accept with very minor revisions” reviews into ”your manuscript has been rejected … on the advice of referees, who have recommended that substantial revisions are necessary”.
In fact, let’s dump the “I can’t imagine how” euphemism and say it how it is: “reviewers recommended substantial revisions” is an outright lie. The reviewers recommended no such thing. The rejection can only be because it’s what the editor wanted to do in spite of the reviewers’ comments not because of them. It left me wondering why I bothered to waste my time offering them an opinion that they were only ever going to ignore.
Then six says ago I heard from the lead author, who had just had a revised version of the same manuscript accepted. (It had not come back to me for review, as the editor had said would happen with any resubmission).
The author wrote to me:
The paper will be published (open access) at the 3rd of Octobre. When I had submitted the corrected version of the ms acceptance was only a formality. So [name] was right, they just want to keep time between submission and publishing date short.
Well. We have a word for this. We call it “lying”. When the editor wrote “your manuscript [...] has been rejected for publication in Biology Letters … With this in mind we would like to invite a resubmission … This is not a provisional acceptance. The resubmission will be treated as a new manuscript”, what she really meant was ”your manuscript [...] has been provisionally accepted, please sent a revision. The resubmission will not be treated as a new manuscript”.
I find this lack of honesty disturbing.
Because we’re not talking here about some shady, obscure little third-world publisher that no-one’s ever heard of with fictional people on the editorial board. We’re talking about the Royal Freaking Society of London. We’re talking about a journal (Biology Letters) that was calved off a journal (Proceedings B) that emerged from the oldest continuously published academic journal in the world (Philosophical Transactions). We’re talking about nearly three and a half centuries of academic heritage.
And they’re lying to us about their publication process.
When did they get the idea that this was acceptable?
And what else are they lying to us about? Can we trust (for example) that when editors or members submit papers, they are subjected to the same degree of rigorous filtering as every other submission? I would have assumed that, yes, of course they do. But I just don’t know any more.
The paper in question is Klein et al.’s (2012) histological study confirming that the bony cervical ribs of sauropods are, as we suspected, ossified tendons — as we assumed in our recently arXiv’d sauropod-neck paper. I am delighted to be able to say that it is freely available. At the bottom of the first page, it says “Received 21 August 2012; Accepted 13 September 2012″, for a submission-to-acceptance time of 23 days. But I know that the initial submission — and remember, the final published version is essentially identical to that initial submission — was made before 17 July, because that’s when I was asked to provide a peer-review. Honest reporting would give a submission-to-acceptance time of 58 days, which is two and a half times as long as the claimed figure.
Now the only reason for a journal to report dates of submission and acceptance at all is to convey the speed of turnaround, and lying about that turnaround time completely removes any utility those numbers might have. It would be better to not report them at all than to fudge the data.
This is another way that the high-impact fast-turnaround publishing system is so ridiculously gamed that it actually hurts science. We have the journal lying to authors about the status of their manuscripts so that it can then lie to the readers about its turnaround times. That’s deeply screwed up. And it’s hard for authors to blow the whistle — they don’t want to alienate the journals and the editors who have some veto power over their tenure beans, and reviewers don’t usually have all the information. The obvious solution is to make the peer-review process more open, and to make editorial decisions more transparent.
That, really, is only what we’d respect from the Royal Society. Isn’t it?
Note. Nicole Klein did not know I was going to post about this. I want to make that clear so that no-one at the Royal Society thinks that she or any of her co-authors is making trouble. All the trouble is of my making (and, more to the point, the Royal Society’s). Someone really has to shine a light on this misbehaviour.
- Klein, Nicole, Andreas Christian, and P. Martin Sander. 2012. Histology shows that elongated neck ribs in sauropod dinosaurs are ossiﬁed tendons. Biology Letters, online first. doi:10.1098/rsbl.2012.0778
Subsequent posts discuss how this issue is developing:
March 15, 2010
On the off chance that the postparapophyses of Shunosaurus weren’t enough to sate your appetite for Sino-pod rib-related weirdness, here are a couple of fused cervicals of Klamelisaurus, from the Middle Jurassic of China (from Zhao 1993:plate 1). These are weird for a couple of reasons. First, although fused caudals are pretty common in sauropods (see here), and fused dorsals turn up a lot (see discussion here), and the fusion of the atlas to the axis is not unheard of (see here and here), fusion of the middle or posterior cervicals is rare. Which makes intuitive sense–presumably fusing up your food-reaching organ is counterproductive. The only other example I know of is the pair of fused posterior cervicals in the AMNH 5761 Camarasaurus supremus (which, oddly enough, I don’t think we’ve covered yet on SV-POW!). If you know of others, please let me know.
Anyway, what’s really weird about the Klamelisaurus verts is not the fusion but the bar of bone connecting the cervical rib of the first vertebra back to one or more of the centra. I think that the weird pseudo-parapophysis-thingy is not the parapophysis of the second vert, which is hanging down just behind, but some kind of extra ossification off the postero-ventro-lateral corner of the first vert’s centrum. Admittedly, that’s a lot of interpretation to hang on one grainy photo of a specimen I’ve never seen. But I’ve seen something similar in some bird cervicals, where there is sometimes a prong or hook of bone from that corner of the centrum sweeping down and out to brace against the longus colli ventralis tendon that comes off the cervical rib. One of the Apatosaurus cervicals on the wall at Dinosaur National Monument has a similar pair of hooks on its posterior centrum. Irritatingly, I don’t have any digitized photos of the Apato vert, and I can’t find any photos at all that show what I’m talking about in birds. Sorry to tantalize, I learned it from Darren. When I get pix, I’ll post ‘em.
In the meantime, you can amuse yourself by pondering the strangeness of the fused Klamelisaurus verts, and by watching the Dinosaur National Monument Quarry Visitor Center get demolished here.
Zhao X. 1993. A new mid-Jurassic sauropod (Klamelisaurus gobiensis gen. et sp. nov.) from Xinjiang, China. Vertebrata PalAsiatica 31(2):132-138.
December 2, 2009
It’s a strange thing, but no-one seems to bother properly figuring their sauropods’ cervical ribs — that is, the long, thin, posteriorly directed ribs of the neck vertebrae. I’ll be bucking that trend when the Archbishop paper comes out, but to get your mouth watering ahead of time, here is the head of the cervical rib that I have arbitrarily designated X1, the largest of those preserved in the Archbishop:
The top image shows the rib in anterior view, with dorsal pointing to the left; the middle row shows the rib with anterior pointing upwards, in (from left to right), lateral, dorsal, medial and ventral views; the bottom row shows posterior view, again with dorsal to the left. Click through the image to see the full glory of the high-resolution version. Remember folks: you only get this sort of high-resolution image published in PLoS journals!
As I mentioned, sauropod cervical ribs have been pretty comprehensively ignored in the literature. I can’t offhand think of a single paper about them (unless you count Martin et al.’s (1998) proposal that they functioned in ventral compression-bracing of sauropods’ necks, and let’s not even start on that), and I am really struggling to think of paper that figures them. Even the usually super-reliable Osborn and Mook (1921) dropped the ball here, with a single illustration (out of 127 figures) and single short paragraph of text (out of 141 pages). Here it is:
Janensch (1950) did discuss the cervical ribs of Giraffatitan in some detail, but his figures are not very informative. If anyone knows of better treatments of sauropod cervical ribs in the literature, then please mention it in the comments!
Because of this poor coverage in the published record, it’s hard for me to compare the Archbishop cervical ribs with those of other taxa. For example, the medial view of X1 (in the middle of the “cross” in the image above) shows that the internal face of the cervical rib loop, where the cervical rib reaches up to articulate with the diapophysis of its vertebra, has two parallel struts of bone extending vertically with a narrow groove between them. Is that unusual? I have no idea.
(I do have photos of some other Tendaguru cervical ribs, referred to Giraffatitan – although if I’m right that the Archbishop is not Giraffatitan, so that there are multiple brachiosaurs in the Tendaguru Formation, then who knows whether that referral is correct?)
Finally, we come to the matter of your cervical ribs. I would have liked to do this post as one in the Your Noun Is Adjective series, but the brutal truth is, you don’t even have any cervical ribs — unless you are one of the lucky 0.2% that, according to the Wikipedia article, have a supernumary rib which is frankly just an additional dorsal rib (uh, thoracic rib I guess) that’s growing out of your last cervical vertebra by mistake. (Wikipedia’s horrible humanist bias is apparent here, in that the article doesn’t even mention the fact that plenty of other animals have cervical ribs and love them.)
Anyway, here’s how human cervical ribs look, stolen from Do You Really Need Back Surgery? A Surgeon’s Guide to Neck and Back Pain and How to Choose Your Treatment:
- Janensch, Werner. 1950. Die Wirbelsaule von Brachiosaurus brancai. Palaeontographica (Suppl. 7) 3:27-93.
- Martin, John, Valérie Martin-Rolland, and Eberhard (Dino) Frey. 1998. Not cranes or masts, but beams: the biomechanics of sauropod necks. Oryctos 1:113-120.
- Osborn, Henry Fairfield, and Charles C. Mook. 1921. Camarasaurus, Amphicoelias and other sauropods of Cope. Memoirs of the American Museum of Natural History, n.s. 3:247-387, and plates LX-LXXXV.
June 22, 2009
This is a taco.
This is a corn dog.
Here’s a cross-section of a human. In the terms of fast food, people are corndogs. Most of us even have an outer ring of yellow adipose ‘breading’.
Here’s a cross-section of a cow. In an example of function following form, cows are, and often become, corndogs.
Note that in both the human and the cow the spaces between the neural spine and transverse processes are completely filled with back muscles, which in fact bulge out beyond the tips of the neural spine, as we also saw here. This despite the common paleoart convention of presenting dinosaurs as thin layers of skin conforming perfectly to the underlying skeleton. Just Say No to shrink-wrapped sauropods!
Here is Figure 17 from Holland (1910), one of the most badass scientific smackdowns ever published, in which Holland wiped the floor with Hay, Tornier, and the idea of sprawling sauropods. On the left are torso skeletons of three lizards and a croc; on the right is an anterior dorsal with articulated ribs from Diplodocus. As you can see, it’s a taco, and its taconic form would be perfected if it could roll supine.
The point of the post is not that sauropods had deep, slab-sided bodies. We’ve covered that before. The point is that sauropod torsos are seriously weird. In mammals, the dorsal ribs arch up and out, away from the vertebra, before sweeping around to define the anterior body wall. In lizards, the proximal part of each rib sticks out sideways. In sauropods, the ribs point down. This is mainly because the vertebrae are FREAKIN’ HUGE compared to the size of the body. Whereas in the mammals and lizards the dorsal vertebrae are titchy little things that span a small fraction of the width of the torso, in Diplodocus and other sauropods the dorsal vertebrae account for about half. (The cow cross-section missed the transverse processes, so that vert looks narrower than it actually is.)
This is relevant when we think about the function of pneumaticity. When I write that pneumaticity lightened vertebrae, I usually mean relative to that same vertebra if it wasn’t pneumatized. But we could also ask if the pneumatic vertebra is lighter than a vertebra from a similar-sized animal that lacks pneumaticity–except that, for big sauropods, there are no similar-sized terrestrial animals without pneumaticity to compare.
Imagine that in a big sauropod the dorsal vertebrae are three times as wide and three times as tall as they would be in a similar-sized mammal. They should weigh nine times more. But let’s also assume that the vertebrae of the sauropod are 85% air by volume, which is in fact pretty typical for Early Cretaceous brachiosaurids. The mass of the dorsal column relative to that of the mammal is then 9 x 0.15 = 1.35, a little heavier, but not much (I’m assuming the length of the torso is the same in the two animals). Bigger bones mean better lever arms for the muscles and lower bending stresses on the ribs, which can function more like curtains and less like cantilevered beams.
I can’t think of much published discussion of this stuff as it relates to sauropods, but it seems like it might be important.
Holland, W.J. 1910. A review of some recent criticisms of the restorations of sauropod dinosaurs existing in the museums of the United States, with special reference to that of Diplodocus carnegiei [sic] in the Carnegie Museum. American Naturalist 44:259-283.