October 27, 2015
When I separated my cat’s head from its body, the first five cervical vertebrae came with it. Never one to waste perfectly good cervicals, I prepped them as well as the skull. Here they are, nicely articulated. (Click through for high resolution.) Dorsal view at the top, then right lateral (actually, slightly dorsolateral) and ventral view at the bottom.
Or you may prefer the same image on a black background:
For those of us used to sauropod necks, where the atlas (C1) is a tiny, fragile ring, mammal atlases look bizarre, with their grotesque over-engineering and gigantic wings.
Copyright: promoting the Progress of Science and useful Arts by preventing access to 105-year-old quarry maps
October 11, 2015
In my recent preprint on the incompleteness and distortion of sauropod neck specimens, I discuss three well-known sauropod specimens in detail, and show that they are not as well known as we think they are. One of them is the Giraffatitan brancai lectotype MB.R.2181 (more widely known by its older designation HMN SII), the specimen that provides the bulk of the mighty mounted skeleton in Berlin.
That photo is from this post, which is why it’s disfigured by red arrows pointing at its epipophyses. But the vertebra in question — the eighth cervical of MB.R.2181 — is a very old friend: in fact, it was the subject of the first ever SV-POW! post, back in 2007.
In the reprint, to help make the point that this specimen was found extremely disarticulated, I reproduce Heinrich (1999:figure 16), which is Wolf-Dieter Heinrich’s redrawing of Janensch’s original sketch map of Quarry S, made in 1909 or 1910. Here it is again:
For the preprint, as for this blog-post (and indeed the previous one), I just went right ahead and included it. But the formal version of the paper (assuming it passes peer-review) will by very explicitly under a CC By licence, so the right thing to do is get formal permission to include it under those terms. So I’ve been trying to get that permission.
What a stupid, stupid waste of time.
Heinrich’s paper appeared in the somewhat cumbersomely titled Mitteilungen aus dem Museum fur Naturkunde in Berlin, Geowissenschaftliche Reihe, published as a subscription journal by Wiley. Happily, that journal is now open access, published by Pensoft as The Fossil Record. So I wrote to the Fossil Record editors to request permission. They wrote back, saying:
We are not the right persons for your question. The Wiley Company holds the copyright and should therefore be asked. Unfortunately, I do not know who is the correct person.
Thank you for your enquiry.
We are currently experiencing a large volume of email traffic and will deal with your request within the next 15 working days.
We are pleased to advise that permission for the majority of our journal content, and for an increasing number of book publications, may be cleared more quickly by using the RightsLink service via Wiley’s websites http://onlinelibrary.wiley.com and www.wiley.com.
Within the next fifteen working days? That is, in the next three weeks? How can it possibly take that long? Are they engraving their response on a corundum block?
So, OK, let’s follow the automated suggestion and try RightsLink. I went to the Wiley Online Library, and searched for journals whose names contain “naturkunde”. Only one comes up, and it’s not the right one. So Wiley doesn’t admit the existence of the journal.
Well, there’s lots to enjoy here, isn’t there? First, and most important, it doesn’t actually work: “Permission to reproduce this content cannot be granted via the RightsLink service.” Then there’s that cute little registered-trademark symbol “®” on the name RightsLink, because it’s important to remind me not to accidentally set up my own rights-management service with the same name. In the same vein, there’s the “Copyright © 2015 Copyright Clearance Center, Inc. All Rights Reserved” notice at the bottom — copyright not on the content that I want to reuse, but on the RightsLink popup itself. (Which I guess means I am in violation for including the screenshot above.) Oh, and there’s the misrendering of “Museum für Naturkunde” as “Museum fÃ¼r Naturkunde”.
All of this gets me precisely nowhere. As far as I can tell, my only recourse now is to wait three weeks for Wiley to get in touch with me, and hope that they turn out to be in favour of science.
It’s Sunday afternoon. I could be watching Ireland play France in the Rugby World Cup. I could be out at Staverton, seeing (and hearing) the world’s last flying Avro Vulcan overfly Gloucester Airport for the last time. I could be watching Return of the Jedi with the boys, in preparation for the forthcoming Episode VII. Instead, here I am, wrestling with copyright.
How absolutely pointless. What a terrible waste of my life.
Is this what we want researchers to be spending their time on?
Update (13 October 2015): a happy outcome (this time)
I was delighted, on logging in this morning, to find I had email from RIGHTS-and-LICENCES@wiley-vch.de with the subject “Permission to reproduce Heinrich (1999:fig. 16) under CC By licence” — a full thirteen working days earlier than expected. They were apologetic and helpful. Here is key part of what they said:
We are of course happy to handle your request directly from our office – please find the requested permission here:We hereby grant permission for the requested use expected that due credit is given to the original source.If material appears within our work with credit to another source, authorisation from that source must be obtained.Credit must include the following components:– Journals: Author(s) Name(s): Title of the Article. Name of the Journal. Publication year. Volume. Page(s). Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.
So this is excellent. I would of course have included all those elements in the attribution anyway, with the exception that it might not have occurred to me to state who the copyright holder is. But there is no reason to object to that.
So, two cheers for Wiley on this occasion. I had to waste some time, but at least none of it was due to deliberate obstructiveness, and most importantly they are happy for their figure to be reproduced under CC By.
- Heinrich, Wolf-Dieter. 1999. The taphonomy of dinosaurs from the Upper Jurassic of Tendaguru, Tanzania (East Africa), based on field sketches of the German Tendaguru expedition (1909-1913). Mitteilungen aus dem Museum fur Naturkunde in Berlin, Geowissenschaftliche Reihe 2:25-61.
October 9, 2015
Since I posted my preprint “Almost all known sauropod necks are incomplete and distorted” and asked in the comments for people to let me know if I missed any good necks, the candidates have been absolutely rolling in:
- The Kaatedocus siberi holotype SMA 0004 (thanks to Oliver Demuth for pointing this out)
- The Futalognkosaurus dukei holotype MUCPv-323 (thanks to Matt Lamanna)
- The referred Rapetosaurus specimen FMNH PR 2209 (Matt Lamanna again)
- The as-yet unnnamed DGM ‘Series A’ titanosaur from Peirópolis (Matt Lamanna again)
- The Camarasaurus lewisi holotype BYU 9047 (thanks to John D’Angelo)
- Dicraeosaurus hansemanni — the mounted “m” specimen, probably MB.R.4886 (thanks to Emanuel Tschopp)
- Maybe some Omeisaurus specimens (Emanuel Tschopp again)
I will be investigating the completeness of all of these and mentioning them as appropriate when I submit the revision of this paper. (In retrospect, I should have waited a week after posting the preprint before submitting for formal review; but I was so scared of letting it brew for years, as we’re still doing with the Barosaurus preprint to our shame, that I submitted it immediately.)
So we probably have a larger number of complete or near-complete sauropod necks than the current draft of this paper suggests. But still very few in the scheme of things, and essentially none that aren’t distorted.
So I want to consider why we have such a poor fossil record of sauropod necks. All of the problems with sauropod neck preservation arise from the nature of the animals.
First, sauropods are big. This is a recipe for incompleteness of preservation. (It’s no accident that the most completely preserved specimens are of small individuals such as CM 11338, the cow-sized juvenile Camarasaurus lentus described by Gilmore, 1925). For an organism to be fossilised, the carcass has to be swiftly buried in mud, ash or some other substrate. This can happen relatively easily to small animals, such as the many finely preserved stinkin’ theropods from the Yixian Formation in China, but it’s virtually impossible with a large animal. Except in truly exceptional circumstances, sediments simply don’t get deposited quickly enough to cover a 25 meter, 20 tonne animal before it is broken apart by scavenging, decay and water transport.
Secondly, even when complete sauropods are preserved, or at least complete necks, distortion of the preserved cervical vertebrae is almost inevitable because of their uniquely fragile construction. As in modern birds, the cervical vertebrae were lightened by extensive pneumatisation, so that they were more air than bone, with the air-space proportion typically in the region of 60–70% and sometimes reaching as high as 89%. While this construction enabled the vertebrae to withstand great stresses for a given mass of bone, it nevertheless left them prone to crushing, shearing and torsion when removed from their protective layer of soft tissue. For large cervicals in particular, the chance of the shape surviving through taphonomy, fossilisation and subsequent deformation would be tiny.
So I think we’re basically doomed never to have a really good sauropod neck skeleton.
October 7, 2015
Well, I’m a moron again. In the new preprint that I just published, I briefly discussed the six species of sauropod for which complete necks are known — Camarasaurus lentus (but it’s a juvenile), Apatosaurus louisae (but the last three and maybe C5 are badly damaged), Mamenchisaurus hochuanensis (but all the vertebrae are broken and distorted), Shunosaurus lii, Mamenchisaurus youngi and Spinophorosaurus nigerensis.
I did have the wit to say, in the Author Comment:
Although I am submitting this article for formal peer-review at the same time as publishing it as a preprint, I also solicit comments from readers. In particular I am very keen to know if I have missed any complete sauropod necks that have been described in the literature. In the final version of the manuscript, I will acknowledge those who have offered helpful comments.
Happily, several people have taken me up on this (see the comments on the preprint), but one suggestion in particular was a real D’oh! moment for me. Oliver Demuth reminded me about Kaatedocus — a sauropod that we SV-POW!sketeers love so much that it has its own category on our site and we’ve held it up as an example of how to illustrate a sauropod specimen. More than that: we have included several illustrations of its vertebrae in one of our own papers.
Aaanyway … the purpose of this post is just to get all the beautiful Kaatedocus multiview images up in one convenient place. They were freely available as supplementary information to the paper, but now seem to have vanished from the publisher’s web-site. I kept copies, and now present them in the conveniently viewable JPEG format (rather the download-only TIFF format of the originals) and with each image labelled with its position in the column.
Please note, these images are the work of Tschopp and Mateus (2012) — they’re not mine!
C15 (and the rest of the skeleton) is missing, which makes this a very nearly, but not quite, complete sauropod neck.
- Tschopp, Emanuel, and Octávio Mateus. 2012. The skull and neck of a new flagellicaudatan sauropod from the Morrison Formation and its implication for the evolution and ontogeny of diplodocid dinosaurs. Journal of Systematic Palaeontology 11(7):853-888. doi:10.1080/14772019.2012.746589
September 14, 2015
We’ve noted that the Taylor et al. SVPCA abstract and talk slides are up now up as part of the SVPCA 2015 PeerJ Collection, so anyone who’s interested has probably taken a look already to see what it was about. (As an aside, I am delighted to see that two more abstracts have been added to the collection since I wrote about it.)
It was my privilege to present a talk on our hypothesis that the distinctive and bizarre toblerone-shaped necks of apatosaurs were an adaptation for intraspecific combat. This talk was based on an in-progress manuscript that Matt is lead-authoring. Also on board is the third SV-POW!sketeer, the silent partner, Darren Naish; and artist/ethologist Brian Engh.
Here is our case, briefly summarised from five key slides. First, let’s take a look at what is distinctive in the morphology of apatosaur cervicals:
Here I’m using Brontosaurus, which is among the more extreme apatosaurs, but the same features are seen developed to nearly the same extent in Apatosaurus louisae, the best-known apatosaur, and to some extent in all apatosaurs.
Now we’ll look at the four key features separately.
First, the cervicals ribs of sauropods (and other saurischians, including birds) anchored the longus colli ventralis and flexor colli lateralis muscles — ventral muscles whose job is to pull the neck downwards. By shifting the attachments points of these muscles downwards, apatosaurs enabled them to work with improved mechanical advantage — that is, to bring more force to bear.
Second, by redirecting the diapophyses and parapophyses ventrally, and making them much more robust than in other sauropods, apatosaurs structured their neck skeletons to better resist ventral impacts.
Third, because the low-hanging cervical ribs created an inverted “V” shape below the centrum, they formed a protective cradle for the vulnerable soft-tissue that is otherwise exposed on the ventral aspect of the neck: trachea, oesophagus, major blood vessels. In apatosaurus, all of these would have been safely wrapped in layers of connective tissue and bubble-wrap-like pneumatic diverticula. The presence of diverticula ventral to the vertebral centrum is not speculative – most neosauropods have fossae on the ventral surfaces of their cervical centra, and apatosaurines tend to have foramina that connect to internal chambers as well (see Lovelace et al. 2007: fig. 4, which is reproduced in this post).
Fourth, most if not all apatosaurs have distinctive ventrally directed club-like processes on the front of their cervical ribs. (It’s hard to tell with Apatosaurus ajax, because the best cervical vertebra of that species is so very reconstructed.) How did these appear in life? It’s difficult to be sure. They might have appeared as a low boss; or, as with rhinoceros horns, they might even have carried keratinous spikes.
Putting it all together, we have an animal whose neck can be brought downwards with great force; whose neck was mechanically capable of resisting impacts on its ventral aspect; whose vulnerable ventral-side soft-tissue was well protected; and which probably had prominent clubs or spikes all along the ventral aspect of the neck. And all of this was accomplished at the cost of making the neck a lot heavier than it would have been otherwise. Off the cuff, it seems likely that the cervical series alone would have massed twice as much in apatosaurines as in diplodocines of the same neck length.
Doubling the mass of the neck is a very peculiar thing for a sauropod lineage to do – by the Late Jurassic, sauropods were the leading edge of an evolutionary trend to lengthen and lighten the neck that had been running for almost 100 million years, through basal ornithodirans, basal dinosauromorphs, basal saurischians, basal sauropodomorphs, and basal sauropods. Whatever the selective pressures that led apatosaurines to evolve such robust and heavy necks, they must have been compelling.
The possibility that apatosaurs were pushing or crashing their necks ventrally in some form of combat accounts for all of the weird morphology documented above, and we know that sexual selection is powerful force that underlies a lot of bizarre structures in extant animals, and probably in extinct ornithodirans as well (see Hone et al. 2012, Hone and Naish 2013).
What form of combat, exactly? There are various possibilities, which we’ll discuss another time. But I’ll leave you with Brian Engh’s beautiful illustration of one possible form of combat: a powerful impact of one neck brought down onto the dorsal aspect of another.
We’re aware that this proposal is necessarily somewhat speculative. But we’re just not able to see any other explanation for the distinctive apatosaur neck. Even if we’re wrong about the ventrolateral processes on the cervical ribs supporting bosses or spikes, the first three points remain true, and given how they fly in the face of sauropods’ long history of making their necks lighter, they fairly cry out for explanation. If anyone has other proposals, we’ll be happy to hear them.
- Hone, D. W., Naish, D., & Cuthill, I. C. (2012). Does mutual sexual selection explain the evolution of head crests in pterosaurs and dinosaurs?. Lethaia 45(2):139-156.
- Hone, D. W. E., & Naish, D. (2013). The ‘species recognition hypothesis’ does not explain the presence and evolution of exaggerated structures in non‐avialan dinosaurs. Journal of Zoology 290(3):172-180.
- Lovelace, D. M., Hartman, S. A., & Wahl, W. R. (2007). Morphology of a specimen of Supersaurus (Dinosauria, Sauropoda) from the Morrison Formation of Wyoming, and a re-evaluation of diplodocid phylogeny. Arquivos do Museu Nacional, Rio de Janeiro 65(4):527-544.
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.
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.
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
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.
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.
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?
In short, yes. Here’s one of the photos I took back in 1994.
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.
June 19, 2015
A while back, we noted that seriously, Apatosaurus is just nuts, as proven by the illustrations in Ostrom and McIntosh (1966: plate 12).
Now I’m posting those illustrations again, in a modified form, to make the same point. Here ya go:
Here’s what’s changed since last time:
- “Apatosaurus” excelsus is Brontosaurus again!
- I cleaned up the scans of the plates, removing all the labels
- In the lateral view, I added a reconstruction of the missing neural spine, based on that of Apatosaurus louisae (from Gilmore 1936: plate XXIV). This reconstruction first appeared in Taylor and Wedel (2013a: figure 7).
- Most importantly, I added the ventral view of the vertebra from plate 13. Only now can you properly appreciate the truly bizarre shape of this bone. (The prezygs appear to project further forward than they should because the illustrated aspect is not true ventral, but slightly anteroventral.)
If only those three views were enough to construct a 3D model by photogrammetry! Sadly, it’s not possible to get photos of the whole vertebra from different angles now, as it’s tied up in the mounted Brontosaurus skeleton at the YPM:
The bottom line: these are some
crazy-ass morphologically distinctive vertebrae. Those ventrolaterally projecting processes that bear the cervical ribs are, for my money, the single most distinctive feature of apatosaurine sauropods. And they reach their zenith (or maybe their nadir, since they point downwards) in Brontosaurus. These processes are the reason that apatosaurs had Toblerone-shaped necks — triangular in cross-section, with the base flat or even concave. Any restoration that shows a tubular neck is way off base.
- Gilmore Charles W. 1936. Osteology of Apatosaurus, with special reference to specimens in the Carnegie Museum. Memoirs of the Carnegie Museum 11:175–300 and plates XXI–XXXIV.
- Ostrom, John H., and John S. McIntosh. 1966. Marsh’s Dinosaurs. Yale University Press, New Haven and London. 388 pages including 65 absurdly beautiful plates.
- Taylor, Michael P., and Mathew J. Wedel. 2013. Why sauropods had long necks; and why giraffes have short necks. PeerJ 1:e36. 41 pages, 11 figures, 3 tables. doi:10.7717/peerj.36