|Darwinopterus robustodens and his pal, a European robin (Erithacus rubecula). When not posing for artwork, they drive around in a van solving mysteries.|
*By 'required', what I really mean is that I'm compelled to construct papers with extraneous artwork in them somewhere, because I'm a sucker for punishment.
Illustrations of Darwinopterus and I go way back. I was asked to do press images for two early publications on it: the initial description and assessment of its unusually 'modular' evolution (Lü et al., 2010), and the equally fantastic discovery of its sexual dimorphism and an egg-mother association (Lü et al., 2011a). Below is the first of these images, published in 2009.
Given that wukongopterids have provided an insight into macroevolutionary processes, filled a gap in pterosaur phylogeny, and present a very unique pterosaur bauplan, expectations may be high that their proposed foraging strategies will also be rather amazing. Fittingly, some have proposed that wukongopterids were pterosaur top guns, their newly evolved long necks and oversize heads being used to prey upon dinosaurs, other pterosaurs, and even gliding mammals in midair (Lü et al. 2010). Such acts would be rather remarkable because, with even a generous mass estimate, the biggest Tiaojishan wukongopterids would not weigh much over 300 g (extrapolating data from Witton 2008), which is about the same as a modern feral pigeon.
At that size, tackling squirrel- sized mammals or crow-sized dinosaurs on the wing would be a feat earning praise from even the hardiest modern raptors, and wukongopterid skeletons would have to be brimming with offensive weaponry for this purpose. Vertebrate-hawking birds are renowned for their talons, incredibly strong feet, robust skulls, and powerful beaks (e.g., Hertel 1995; Fowler et al. 2009), while bats that subdue large vertebrates in flight are also armed with formidable teeth and powerful jaws (Ibáñez et al. 2001). These adaptations provide the means to immobilize their prey quickly and efficiently, and are obvious advantages for animals grappling with large prey while in flight. Vertebrate hawkers are also powerful fliers that can chase down their quarry and, once immobilized, carry the prey to a safe spot to eat. Pterosaurian equivalents would therefore require equally powerful flight musculature to permit the same tasks. Unfortunately for the Darwinopterus raptor hypothesis, wukongopterids do not possess any of these requirements. None of their appendages bear the chunky digits and talons ideal for subduing large aerial prey items, and their long, comparatively delicate skulls and unimpressive teeth are ill suited to this task. Nor, for that matter, do they have the expanded shoulder regions indicative of the powerful flight muscles needed to chase and eventually carry their prey. With this in mind, raptorial pursuits look doubtful for wukongopterids.
Witton (2013), p. 141-142.There's a lot more that could have been said about this, but you get the idea: Darwinopterus and chums were small (jackdaw-sized - see image at the top of the post), delicately built animals for which aerial predation seems counter-intuitive and unlikely. I'm not the only person saying this, either: Lü et al. (2011b) and Sullivan et al. (2014) also raise points against the aerial hawking idea. We could go so far as to to label wukongopterid aerial hawking as another example of an 'extreme' palaeoecology based on cherry picked characteristics rather than considering a full suite of functional data.
So, on reflection, we probably started on the wrong foot but, hey, what can you do? Working as an artist is quite different to being involved in research: ultimately, you're a guy with a paintbrush being told to illustrate someone else's idea, even if you don't necessarily agree with it (also see Csotonyi and White 2014). With the notion of aerial predation being raised in the paper, specifically as a possible explanation for the development of pterodactyloid head and neck features Lü et al. (2010), it was an obvious choice for the image. But we didn't help matters by walking into some of the cheesiest, silliest things stereotypes of palaeoart, primarily because we were trying to make a small, fairly inoffensive animal look like a skydiving, dinosaur-eating-badass. We tried several different takes on this, varying aerial and terrestrial prey, and compositions which upped the voracity, such as this:
|You'll need to make your own whooshing jet fighter noises and 'pew pew' laser sounds.|
The result isn't awful, but I think I've had more successful collaborations with the same authors, just because this doesn't feel realistic at all. From the science to the composition, the whole thing just seems 'forced'. Don't get me wrong: I'm sure Darwinopterus could be terrifying instruments of mortality to the right prey (probably terrestrial invertebrates according to Lü et al. 2011b and Witton 2013), and I'm not belittling the drama or viciousness which can occur in the lives of small animals. But life - thank God - doesn't look like the cover of a Meat Loaf album. There are some fossil animals that can - just about - pull off Meat Loaf palaeoart, but it's just not possible to turn small, fluffy, unthreatening animals into monsters. When we do, they're more liable to look goofy than impressive. Despite this, we do it all the time. I understand why we do - it's exciting and marketable, and feeds into expectation that Deep Time as a monster-filled fantasy realm - but it also reinforces the perception that palaeoart is unsophisticated and aimed at children. But there may be another way.
Palaeontologists: next time you have a new, diminutive animal you want illustrated, forget the monster: play the cute card. The chubby little Darwinopterus at the top of this post intuitively seems closer to the reality of this animal than Darwinopterus 2009: AwesomeoSuperKiller. It's proportions, fluffiness and posture are all accurate, and it only looks cute because, well, it probably was: it's a small fuzzball with an oversize head and mischievous grin. If the Internet's obsession with cats and baby sloths has taught us anything, it's that cute sells better than violence. Indeed, this image is one of the most popular things I've ever put on Facebook, and (at time of writing) it was posted less than a day ago. The great thing about the cute card is that everyone wins: the artwork should promote research just as well or better than it's Meat Loaf variant, because it appeals to wider demographics. The artist gets to render an animal in a more realistic light without jumping through hoops to monsterise it, and the world gets a new picture to 'coo' at. A few folks might even start to appreciate extinct animals in ways they never could when they're always shown screaming and fighting.
And if nothing else, it will mean we'll never have to discuss Meat Loaf album covers here again.
|May God have mercy on us all. (Wikipedia)|
- Csotonyi, J. & White, S. (2014). The Paleoart of Julius Csotonyi: Dinosaurs, Sabre Tooths and Beyond. Titan Books, London.
- Fowler, D. W., Freedman, E. A., & Scannella, J. B. (2009). Predatory functional morphology in raptors: interdigital variation in talon size is related to prey restraint and immobilisation technique. PloS one, 4(11), e7999.
- Hertel, F. (1995). Ecomorphological indicators of feeding behavior in recent and fossil raptors. Auk, 112(4), 890-903.
- Ibáñez, C., Juste, J., García-Mudarra, J. L., & Agirre-Mendi, P. T. (2001). Bat predation on nocturnally migrating birds. Proceedings of the National Academy of Sciences, 98(17), 9700-9702.
- Lü, J., Unwin, D. M., Jin, X., Liu, Y., & Ji, Q. (2010). Evidence for modular evolution in a long-tailed pterosaur with a pterodactyloid skull. Proceedings of the Royal Society B: Biological Sciences, 277(1680), 383-389.
- Lü, J., Unwin, D. M., Deeming, D. C., Jin, X., Liu, Y., & Ji, Q. (2011a). An egg-adult association, gender, and reproduction in pterosaurs. Science, 331(6015), 321-324.
- Lü, J., Xu, L., Chang, H., & Zhang, X. (2011b). A new darwinopterid pterosaur from the Middle Jurassic of western Liaoning, northeastern China and its ecological implications. Acta Geologica Sinica‐English Edition, 85(3), 507-514.
- Sullivan, C., Wang, Y., Hone, D. W., Wang, Y., Xu, X., & Zhang, F. (2014). The vertebrates of the Jurassic Daohugou Biota of northeastern China. Journal of Vertebrate Paleontology, 34(2), 243-280.
- Witton, M. P. (2008). A new approach to determining pterosaur body mass and its implications for pterosaur flight. Zitteliana, 143-158.
- Witton, M. P. (2013). Pterosaurs: Natural History, Evolution, Anatomy. Princeton University Press.