December 17, 2012
I happened to be browsing Gerald L. Woods superb Guinness Book of Animal Facts and Feats (3rd edition) this morning, and happened across this fragment on page 76:
Not surprisingly, hummingbirds have the highest energy output per unit of weight of any living warm-blooded animal.
The wording struck me as strange: highest of any living warm-blooded animal? Is Wood just being redundant here, or is he implying that there are cold-blooded animals with a higher mass-specific metabolic rate? The idea seems inherently contradictory, doesn’t it?
I wondered whether he might have insect flight in mind?
Am I making a mistake in conflating “energy output” with “metabolic rate”?
October 18, 2012
Another blast from the past:
Like the recent Compsognathus, this is a card from the “Flesh” card-game that was printed across several progs (issues) of the comic 2000 AD in 1977. This one is from the back cover of Prog 10. (Click through the picture for the whole back cover.)
What’s interesting about this one is how very flagrant a rip-off it is of Rudolph Zallinger’s 1960 painting of Brontosaurus being attacked by Allosaurus:
I know this painting best from Dinosaurs and other Prehistoric Reptiles, a 1966 book that I had as a boy, and which I believe is the same thing as the Giant Golden Book of Dinosaurs. Here is a high-resolution scan of my copy of that book, pages 24-25. (Click through for 5472 by 3669 version.)
And while I’m here, I may as well throw in my scan of the “Brachiosaurus” (i.e. Giraffatitan)on pages 20-21. (Click through for 5431 by 3162 version.)
I will leave it to others to point out which other classic piece of sauropod art this one plagiarises.
October 2, 2012
Here’s a blast from the past:
This alleged Compsognathus is a card from the “Flesh” card-game that was printed across several progs (issues) of the comic 2000 AD in 1977. This one is from the back cover of Prog 9. (Click through the picture for the whole back cover.)
“Flesh” was one of the half-dozen or so stories that appeared each week in those early months of 2000 AD. It was the story of how cowboys of the future travelled back to the Mesozoic to harvest dinosaurs for their meat, and was the subject of Jeff Liston’s chapter in the recentish Geological Society volume on the history of dinosaur research.
Compsognathus made another pop-culture appearance in The Lost World: Jurassic Park, of course, as the cute little “compys” that tear one of the nastier human characters to pieces.
Why does the 2000 AD Compsognathus have actinopterygian-like fins for arms? According to Wikipedia, The idea comes from Bidar et al. (1972), who supposed that the French specimen had webbed forefeet, which would look like flippers in life — an idea illustrated as part of a larger scene by Halstead (1975):
John Ostrom’s (1978) Compsognathus monograph showed that this was nonsense, but of course that was too late for the early issues of 2000 AD.
Bidar, A.; Demay L., Thomel G. 1972. Compsognathus corallestris, une nouvelle espèce de dinosaurien théropode du Portlandien de Canjuers (Sud-Est de la France). Annales du Muséum d’Histoire Naturelle de Nice 1:9–40.
Halstead L.B. 1975. The evolution and ecology of the dinosaurs. Eurobook. ISBN 0-85654-018-8.
Ostrom, J.H. 1978. The osteology of Compsognathus longipes. Zitteliana 4:73–118.
Update 1 (the next day)
In a comment below, Andrea Cau points to this post on his blog Theropoda (“the most inclusive blog containing Allosaurus fragilis but not Saltasaurus loricatus) which contains two more flippered-Compsognathus illustrations. Here they are: one from David Lambert’s book Dinosaur! …
… and one from David Norman’s Illustrated Encyclopedia of Dinosaurs.
Update 2 (two days later)
Silly me, I should of course have posted Bidar et al.’s (1972) own life restoration of Compsognathus. It’s not great art, but it’s … actually, I’m not sure what it is. But anyway, here it is:
September 26, 2012
Today sees the publication, on arXiv (more on that choice in a separate post), of Mike and Matt’s new paper on sauropod neck anatomy. In this paper, we try to figure out why it is that sauropods evolved necks six times longer than that of the world-record giraffe — as shown in Figure 3 from the paper (with a small version of Figure 1 included as a cameo to the same scale):
This paper started life as a late-night discussion over a couple of beers, while Matt was over in England for SVPCA back in (I think) 2008. It was originally going to be a short note in PaleoBios, just noting some of the oddities of sauropod cervical architecture — such as the way that cervical ribs, ventral to the centra, elongate posteriorly but their dorsal counterparts the epipophyses do not.
As so often, the tale grew in the telling, so that a paper we’d initially imagined as a two-or-three-page note became Chapter 5 of my dissertation under the sober title of “Vertebral morphology and the evolution of long necks in sauropod dinosaurs”, weighing in at 41 1.5-spaced pages. By now the manuscript had metastatised into a comparison between the necks of sauropods and other animals and an analysis of the factors that enabled sauropods to achieve so much more than mammals, birds, other theropods and pterosaurs.
(At this point we had one of our less satisfactory reviewing experiences. We sent the manuscript to a respected journal, where it wasn’t even sent out to reviewers until more than a month had passed. We then had to repeatedly prod the editor before anything else happened. Eventually, two reviews came back: one of them careful and detailed; but the other, which we’d waited five months for, dismissed our 53-page manuscript in 108 words. So two words per page, or about 2/3 of a word per day of review time. But let’s not dwell on that.)
This work made its next appearance as my talk at SVPCA 2010 in Cambridge, under the title Why giraffes have such short necks. For the talk, I radically restructured the material into a form that had a stronger narrative – a process that involved a lot of back and forth with Matt, dry-running the talk, and workshopping the order in which ideas were presented. The talk seemed to go down well, and we liked the new structure so much more than the old that we reworked the manuscript into a form that more closely resembled the talk.
That’s the version of the manuscript that we perfected in New York when we should have been at all-you-can-eat sushi places. It’s the version that we submitted on the train from New York to New Haven as we went to visit the collections of the Yale Peabody Museum. And it’s the version that was cursorily rejected from mid-to-low ranked palaeo journal because a reviewer said “The manuscript reads as a long “story” instead of a scientific manuscript” — which was of course precisely what we’d intended.
Needless to say, it was deeply disheartening to have had what we were convinced was a good paper rejected twice from journals, at a cost of three years’ delay, on the basis of these reviews. One option would have been to put the manuscript back into the conventional “scientific paper” straitjacket for the second journal’s benefit. But no. We were not going to invest more work to make the paper less good. We decided to keep it in its current, more readable, form and to find a journal that likes it on that basis.
At the moment, the plan is to send it to PeerJ when that opens to submissions. (Both Matt and I are already members.) But that three-years-and-rolling delay really rankles, and we both felt that it wasn’t serving science to keep the paper locked up until it finally makes it into a journal — hence the deposition in arXiv which we plan to talk about more next time.
In the paper, we review seven characteristics of sauropod anatomy that facilitated the evolution of long necks: absolutely large body size; quadrupedal stance; proportionally small, light head; large number of cervical vertebrae; elongation of cervical vertebrae; air-sac system; and vertebral pneumaticity. And we show that giraffes have only two of these seven features. (Ostriches do the next best, with five, but they are defeated by their feeble absolute size.)
The paper incorporates some material from SV-POW! posts, including Sauropods were corn-on-the-cob, not shish kebabs. In fact, come to think of it, we should have cited that post as a source. Oh well. We do cite one SV-POW! post: Darren’s Invading the postzyg, which at the time of writing is the only published-in-any-sense source for pneumaticity invading cervical postzygapogyses from the medial surface.
As for the non-extended epipophyses that kicked the whole project off: we did illustrate how they could look, and discussed why they would seem to make mechanical sense:
But we found and explained some good reasons why this apparently appealing arrangement would not work. You’ll need to read the paper for details.
Sadly, we were not able to include this slide from the talk illustrating the consequences:
Anyway, go and read the paper! It’s freely available, of course, like all arXiv depositions, and in particular uses the permissive Creative Commons Attribution (CC BY) licence. We have assembled related information over on this page, including full-resolution versions of all the figures.
In the fields of maths, physics and computer science, where deposition in arXiv is ubiquitous, standard practice is to go right ahead and cite works in arXiv as soon as they’re available, rather than waiting for them to appear in journals. We will be happy for the same to happen with our paper: if it contains information that’s of value to you, then feel free to cite the arXiv version.
September 21, 2012
In a comment on the previous post, Emily Willoughby links to an excellent post on her own blog that discusses the “necks lie” problem in herons. Most extraordinarily, here are two photos of what seems to be the same individual:
You should get over to Emily’s blog right now and read her article. (Kudos, too, for the Portal reference in the title. I’ve been playing Portal and Portal 2 obsessively for the last week. Quite brilliant, and a very rare example of true innovation in computer gaming.)
Also of interest: this composite of two shoebill (Balaeniceps rex) individuals, which I made from two of the images mentioned in a comment by AL on Emily’s post:
Oh, birds, you crazy creatures!
September 20, 2012
Back when we were at Cambridge for the 2010 SVPCA, we saw taxidermied and skeletonised hoatzins, and were struck that the cervical skeleton was so very much longer than the neck as it appears in life — because necks lie. At Oxford last week for the 2012 SVPCA, we saw a similar pair of hoatzin mounts (one adult, one juvenile) that clarified the situation:
And here is juvenile in side-view:
As you can see, it’s folding its neck way down out of the way, so that externally it appears much shorter. (And comparing with the Cambridge specimen, you can see that the neck skeleton is proportionally much longer than this in adult.)
Why does it do this? I have no idea.
But I do know it’s not unique to hoatzins. Another nice illustration of how misleading birds’ necks are when viewed in a live animal is this parrot (probably Amazona ochrocephala) in the Natuurhistorisch Museum of Rotterdam (from this Love in the Time of Chasmosaurs post):
One thing that’s not clear to me is how much of the neck the bird can extend in life. If the parrot wants to uncoil all that spare cervical skeleton to reach upwards or forwards, can it? Will the soft tissue envelope allow it? My guess is not, otherwise you’d surely see them doing it. But then … why is all that neck in there at all?
September 18, 2012
Friday evening I was in a pub with Mike, Darren, John Conway, and Emma Lawlor. We were killing time waiting for the Pink Giraffe Chinese restaurant down the street to open. I was chatting with John about “All Todays”, his speculative presentation with Cevdet Kosemen (a.k.a. Nemo Ramjet) on how future sentients might reconstruct Holocene animals if they were known only from fossils. Like his “All Yesterdays” presentation last year, John’s flights of scientific fancy had fired my imagination and gotten me thinking about how paleontology forms sort of a skin or membrane between the bubble of what we know and the surrounding ocean of what we don’t. I decided that we should pass a pad around and each sketch a speculative sauropod.
My own entry is based on the holotype of Mamenchisaurus hochuanensis, which was found almost complete except for the skull (naturally) and forelimbs. I have often joked that diplodocids were basically bipeds whose forelimbs happened to reach the ground. Mamenchisaurs were probably not that back-heavy, but their presacral vertebrae were extremely pneumatic and if our hypothetical future paleontologists had no other sauropod material to work with, I think it’s possible that they would reconstruct the M. hochuanensis holotype as a biped.
I’m not sure there’s much to say about Mike’s brachiosaur, beyond the Ebert-like observation that if a brachiosaur dressed up in a coat and top hat and went cruising for dames, this, I am forced to conclude, is more or less how it would look.
John Conway also drew a mamenchisaur, this time Mamenchisaurus youngi with its bizarrely bent-back sacrum. John’s explanation for the weird sacrum brings to mind ground sloths and–for those who saw “All Yesterdays” at SVPCA 2011–a certain black-feathered therizinosaur. I’d also like to note that he knocked this out in about 5 minutes, thus demonstrating the difference between a professional artist and a mere doodler like myself.
Darren’s hindlimb-less sauropod complements my bipedal Mamenchisaurus. Here the animal, evidently known from only the front half of the skeleton, has been restored as a giant bird. Dig the giant thumb claws and spreading metapodials. Surely, you say, future paleontologists of any species or machine culture would know a pectoral girdle when they saw one. But I’ll bet a sauropod scapulocoracoid could pass for an ilium, if said future paleontologists were still in the early stages of understanding the morphology and diversity of vertebrates. Remember that Seeley described the sauropod Ornithopsis as “a gigantic animal of the pterodactyle kind” based on its pneumatic vertebrae. There is also a long and honorable (?) tradition of mistaking sauropods for hadrosaurs (Sonorasaurus), theropods (Bruhathkayosaurus), and tree trunks (Sauroposeidon), so don’t be too quick to rule this out.
What I want to see next is a skeletal reconstruction of Darren’s sauro-bird, using only elements from the front half of a sauropod skeleton. Anyone want to give it a shot?
Our penultimate entry is Emma’s rendering of an evil bastard snake devouring an innocent baby sauropod. Tragically this one is not speculative–we have very good fossil evidence that the scene shown here really happened, probably a lot. She tried to make it up to us with a smiley face on the next page, but it was too late. We were so depressed after this that we could barely choke down four courses of excellent Chinese food.
One more for the road: a totally new depiction of the enigmatic sauropod Xenoposeidon by yours truly. I expect to see this incorporated into future talks and papers dealing with European sauropod diversity in the Early Cretaceous. Just credit me as you normally would.
That’s all, folks. I hope that speculative sauropod sketches get to be a Thing, and that we see lots more of them from future conferences.
July 11, 2012
June 24, 2012
Sometimes you just can’t make this stuff up.
You may recall a story from the Onion Our Dumb Century book, allegedly from 1904, about the skeleton of Satan being discovered in Wyoming. Mike used his occult powers to put together this scan from freely available online sources:
If you scrutinize the above image carefully, you’ll see that ‘Satan’ is an Allosaurus (I’m no theropod booster, but I always thought that was a little harsh on T. rex).
Why am I telling you this? Because last week Mike and I were toiling in the big bone room in the basement of the AMNH when we came across AMNH 666.
It’s an ilium. (Of course it would have to be an appendicular element. Vertebrae are from on high [or dorsal, if you prefer].)
The stomach-churning color here could be a manifestation of diabolical power, or just what happens when you try to photograph a pink specimen label on a yellow-orange forklift.
After this harrowing encounter, we cleansed our bodies, minds, and souls with street-vendor hot dogs and The Avengers.* That particular mode of exorcism may not be the most effective–I felt distinctly dodgy that evening. But the next day we received illumination at the Altar of Sauropod Awesomeness and were soon back to what we jokingly refer to as normal.
* The best way to see The Avengers is by going up to the observation deck of the Empire State Building shortly beforehand, so big swathes of the Manhattan skyline will still be in your mental RAM during the big final battle. I understand it’s not an option for everyone.
June 19, 2012
Matt pointed out to me something that in retrospect is obvious, though I’d never thought about it before: the eyelashes of birds are not homologous with ours, since mammals’ eyelashes are modified hairs and birds don’t have hair. Instead, their lashes are modified feathers. It would be interesting to see both kinds of eyelash under a microscope and compare.
It certainly looks as though these “feathers” are simple unbranched filaments — much like the earliest protofeathers found on so many of those wacky Chinese raptors. I wonder how closely they resemble the ancestral state?