October 22, 2015
I’d hoped that we’d see a flood of BRONTOSMASH-themed artwork, but that’s not quite happened. We’ve seen a trickle, though, and that’s still exciting. Here are the ones I know about. If anyone knows of more, please let me know and I will update this post.
And in close-up:
Very elegant, and it’s nice to see an extension of our original hypothesis into other behaviours.
The next thing I saw was Mark Witton’s beautiful piece, described on his own site (in a post which coined the term BRONTOSMASH):
And in close-up:
I love the sense of bulk here — something of the elephant-seal extant analogue comes through — and the subdued colour scheme. Also, the Knight-style inclusion in the background of the individual in the swamp. (No, sauropods were not swamp-bound; but no doubt, like elephants, they spent at least some time in water.)
And finally (for now, at least) we have Matthew Inabinett’s piece, simply titled BRONTOSMASH:
I love the use of traditional materials here — yes, it still happens! — and I like the addition of the dorsal midline spike row to give us a full on TOBLERONE OF DOOM. (Also: the heads just look right. I wish I could do that. Maybe one day.)
Update (Monday 26 October)
Here is Oliver Demuth’s sketch, as pointed out by him in a comment.
Thanks, Oliver! Nice to see the ventral-on-dorsal combat style getting some love.
So that’s where we are, folks. Did I miss any? Is anyone working on new pieces on this theme? Post ’em in the comments!
October 19, 2015
I imagine that by now, everyone who reads this blog is familiar with Mark Witton’s painting of a giant azhdarchid pterosaur alongside a big giraffe. Here it is, for those who haven’t seen it:
(This is the fifth and most recent version that Mark has created, taken from 9 things you may not know about giant azhdarchid pterosaurs.)
It’s one of those images that really kicks you in the brain the first time you see it. The idea that an animal the size of a giraffe could fly under its own power seems ludicrous — yet that’s what the evidence tells us.
But wait — what do we mean by “an animal the size of a giraffe”? Yes, the pterosaur in this image is the same height as the giraffe, but how does its weight compare?
Mark says “The giraffe is a big bull Masai individual, standing a healthy 5.6 m tall, close to the maximum known Masai giraffe height.” He doesn’t give a mass, but Wikipedia, citing Owen-Smith (1988), says “Fully grown giraffes stand 5–6 m (16–20 ft) tall, with males taller than females. The average weight is 1,192 kg (2,628 lb) for an adult male and 828 kg (1,825 lb) for an adult female with maximum weights of 1,930 kg (4,250 lb) and 1,180 kg (2,600 lb) having been recorded for males and females, respectively.” So it seems reasonable to use a mass intermediate between those of an average and maximum-sized male, (1192+1930)/2 = 1561 kg.
So much for the giraffe. What does the azhdarchid weigh? The literature is studded with figures that vary wildly, from the 544 kg that Henderson (2010) found for Quetzalcoatlus, right down to the widely cited 70 kg that Chatterjee and Templin (2004) found for the same individual — and even the astonishing 50 kg that seems to be favoured by Unwin (2005:192). In the middle is the 259 kg of Witton (2008).
It occurred to me that I could visualise these mass estimates by shrinking the giraffe in Mark’s image down to the various proposed masses, and seeing how credible it looks to imagine these reduced-sized giraffes weighting the same as the azhdarchid. The maths is simple. For each proposed azhdarchid mass, we figure out what it is as a proportion of the giraffe’s 1561 kg; then the cube root of that mass proportion gives us the linear proportion.
- 544 kg = 0.389 giraffe masses = 0.704 giraffe lengths
- 259 kg = 0.166 giraffe masses = 0.549 giraffe lengths
- 70 kg =0.0448 giraffe masses = 0.355 giraffe lengths
Let’s see how that looks.
On the left, we have Mark’s artwork, with the giraffe massing 1561 kg. On the right, we have three smaller (isometrically scaled) giraffes of masses corresponding to giant azhdarchid mass estimates in the literature. If Don Henderson (2010) is right, then the pterosaur weighs the same as the 544 kg giraffe, which to me looks pretty feasible if it’s very pneumatic. If Witton (2008) is right, then it weighs the same as the 259 kg giraffe, which I find hard to swallow. And if Chatterjee and Templin (2004) are right, then the giant pterosaur weighs the same as the teeny tiny 70 kg giraffe, which I find frankly ludicrous. (For that matter, 70 kg is in the same size-class as Georgia, the human scale-bar: the idea that she and the pterosaur weigh the same is just silly.)
What is the value of such eyeball comparisons? I’m not sure, beyond a basic reality check. Running this exercise has certainly made me sceptical about even the 250 kg mass range which now seems to be fairly widely accepted among pterosaur workers. Remember, if that mass is correct then the pterosaur and the 259 kg giraffe in the picture above weight the same. Can you buy that?
Or can we find extant analogues? Are there birds and mammals with the same mass that are in the same size relation as these images show?
- Chatterjee, Sankar, and R. J. Templin. 2004. Posture, locomotion, and paleoecology of pterosaurs. Geological Society of America, Special Paper 376. 68 pages.
- Henderson, Donald M. 2010. Pterosaur body mass estimates from three-dimensional mathematical slicing. Journal of Vertebrate Paleontology 30(3):768-785.
- Witton, Mark P. 2008. A new approach to determining pterosaur body mass and its implications for pterosaur flight. Zitteliana 28:143-159.
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 30, 2015
Here’s the last post (at least for now) in the Fighting Apatosaur Art series — and we’re back to Brian Engh, who we started with.
Early in the process of putting together artwork to illustrate our apatosaur neck combat hypothesis, Brian tried out a whole bunch of outlandish concepts. Here are two that he showed us, but which were too speculative to push forward with. First, necks as big, floppy display structures:
As a piece of art, I really like this one: the boldness, the vivid contrasts, the alien quality of the animals. But as a palaeobiological hypothesis, it doesn’t really work: so much of the neck morphology in apatosaurs is to do with absorbing ventral forces that soft-tissue display structures down there don’t make a whole lot of sense.
Here’s the other one — which Brian titles “Apatosaur inflato-porcupine fish neck-bag”.
I particularly like the way the theropod being rolled around on the ground and repeatedly spiked. It’s no more than it deserves.
Does the idea of an inflatable neck make sense? I wouldn’t be at all surprised if there were sauropods that did something like this — plenty of extant animals inflate parts of their body for display purposes, after all — but I don’t think it would have been apatosaurs. Again, the characteristic features of the neck don’t seem well matched to this scenario.
Well, that’s all the apatosaur neck-combat art we have. If there’s to be a part 7 in this series, it will be made of artwork that you, dear readers, have contributed. Fire away!
September 28, 2015
If we accept that the distinctive ventral projections of the gigantic and ventrally displaced cervical ribs of apatosaurs were likely the base of some form of soft-tissue rugosity — such as keratinous horns like those of rhinos — then does it follow that those necks were used in combat as we suggested?
Maybe, maybe not. As scientists, we are always open to other hypotheses. We’re looking for the simplest, most parsimonious model — the one which best explains the facts.
That’s why we like Mark Witton’s “neck-velcro wall-climbing” hypothesis, as shown in this actual scientific life restoration.
As Mark explained to me, apatosaurs may have used their neck-hooks for more than passive clinging. They may also have been used for inching up the rock-face: first one side of the neck advancing and then the next, in the manner of the “pterygoid walking” that snakes use to progressively swallow large prey.
This is why it’s important to present early-stage work at conferences (and as preprints). Otherwise, you may never hear about important alternative hypotheses like this until after the paper is out and it’s too late to include them.
September 27, 2015
I mentioned last time that, as I sat next to Bob Nicholls in an SVPCA session, I started sketching an apatosaur combat in the hope that my horrible drawing would provoke Bob to do a good one. That worked admirably, which means there is no good reason for me to subject you to my own sketch.
So here it is.
I think the main lessons to draw from this piece are:
- I can’t draw heads.
- I can’t draw limbs.
- I can’t draw torsos.
- I may be just about capable of drawing tails.
During a break, I asked for Bob’s advice on how I can do better. I know I’ll never be an artist, but it’s fun to sketch (especially during mammal talks) and I’d like to improve a little. The main point Bob made was to think about where the light is coming from. Be consistent about that, and you get an immediate improvement in realism.
So here’s what I sketched the next day, with that in mind:
So what have we learned this time?
- I didn’t consciously do this, but I ended up with a composition kind of similar to what Bob came up with, but worse.
- In my desire to achieve the intertwined-necks pose, I made the necks too long and thin.
- I still can’t draw heads.
- Let’s just forget about the hindlimb of the one on the left.
- Uh, and let’s forget the torsos, too.
- But at least the light is coming from top right!
In short, as Stephen Sondheim put it, art isn’t easy. I wish I had more time to put into it.
The real moral of this story is: if I had a crack at drawing fighting apatosaurs, you definitely can. Let us know if you do — leave a comment. We’ll gather people’s contributions in a future post.
September 25, 2015
On the morning of Tuesday 1st December, on SVPCA day 1, I gave my talk about apatosaur neck combat. In one of the afternoon sessions, I sat next to Bob Nicholls, and found myself thinking how awesome it would be if he sketched some apato-combat.
But I didn’t want to come right out and say “Hey, Bob, how ’bout you spontaneously illustrate our palaeobiological hypothesis?” So instead I used a tactic that Fiona often uses when she wants me to do something: she starts to do it herself, badly, and waits for me to take over. (This is often how I find myself cooking in the evenings.) In the same spirit, sat next to Bob, I started a horrible sketch of wrestling apatosaurs. Sure enough, Bob, saw what I was doing, internally decided it ought to be done properly, and produced this:
What I love most about this (beside the casual way he knocked it out in fifteen minutes) is the sense of heft about the apatosaurs. These are big, solid animals. Someone’s gonna get hurt.