Monday 30 June 2014

Azhdarchid pterosaurs vs. the world

Azhdarchids: also available in flying. Depicted animal here is based on Quetzalcoatlus sp., but no taxon in particular.
In just a few weeks the world will stop for TetZooCon, a one day convention of all things we associate with the famous Tetrapod Zoology blog and podcast - tetrapods real and scientifically-speculative from wondrous, charismatic fossil reptiles to deceptively interesting small, brown herpetofauna. If you’re reading this, you’re slap bang in the middle of the TetZoo demographic and I guarantee* you’ll have a good time. Tickets are available until Friday 4th July, and it’s all going down one week later - Saturday 12th. Get your place while you can, or forever live with the shame.

*Guarantee not guaranteed.

In a surprise move, my contribution to TetZooCon features pterosaurs. Specifically, I’m looking at the way one group of pterosaurs has made major ripples in the palaeontology pond in recent years - and not just scientifically. The changing face of pterosaur science is certainly interesting, but an equally intriguing, rarely told story exists on the popular face of flying reptile research. To whet your appetite, here’s an 'extended abstract' of my TetZooCon talk, giving some insight into what I'll be covering in a couple of weeks.

PteroPop

Pterosaurs are not unfamiliar characters in popular culture. They have been mainstays of science fiction literature since at least 1874 (Jules Verne’s Journey to the Centre of the Earth), made the jump to the silver screen in 1925 (The Lost World), and since starred in uncountable stories of time-travel, lost worlds and Jurassic Park-inspired de-extinction fiction. Neither are they strangers to public education, from being part of Benjamin Waterhouse Hawkins’ 1854 Crystal Palace menagerie to modern appearances in £multi-million documentaries. These historic popular pterosaurs rarely showed much adherence to flying reptile science: their appearances, behaviours and lifestyles mostly reflect a shorebird-like 'pterosaur archetype' rather than the specific anatomy and habits of a once-living taxon.

One of the many curious things about early azhdarchid reconstructions is the head nubbin - a short, posteriorly-directed conical(?) crest on the back of the head. There is nothing like this known from any azhdarchid. Far from being an early mistake, reconstructions with head nubbins persist until at least 2000. Slide from my TetZooCon talk.
But all that is changing. One pterosaur lineage has overshadowed ‘generic’ popular pterosaurs to bring aspects of ‘real’ pterosaurology to the masses, and has even stolen some limelight from dinosaur celebrities in the process. Media as disparate as documentaries and comic books show these animals in (basically) anatomically correct forms, with accurate but atypical postures, and behaviours which are far removed from the idea of pterosaurs being ancient seabird analogues. The animals in question are, of course, the long-necked, toothless and gigantic flying reptiles, Azhdarchidae.

In some respects, the recent surge of azhdarchid pop-culture uptake is a bit strange. It is not, for instance, that azhdarchids are a newly discovered group. Far from it, their fossils were found by at least the latest 1930s or early 1940s; good remains were apparent the 1970s, and the concept of Azhdarchidae was formalised in the early 1980s. They’re not new to popular culture either, having hung around its periphery since the 1970s to be wheeled out as 'Largest Flying Animals Ever' on occasion. These early popular azhdarchids showed little uniformity in their reconstruction - maybe even less than other pterosaurs at that time. Most bore little resemblance to actual azhdarchid fossils, either anatomically of functionally (above). They were depicted with huge variation from the 1970s-1990s: hugely elongate and narrow wings, or broad, kite-like wings? Longirostrine skulls with snub-noses or tiny pin-heads? Toothed or toothless jaws? Short necks, long necks with swan-like flexibility, or long necks stiffer than broom handles? Art produced in the 1980s - 2D work by Greg Paul, Paul MacCready’s 1985 glider (below), and a (largely sculpted) azhdarchid skeleton mounted by the Texas Memorial Museum - were probably the first works to strike close to reality, but they’re still a bit short of the mark. John Sibbick’s better known and more influential 1991 snub-nosed Quetzalcoatlus was a step back from these more accurate works, accidentally making a chimeric azhdarchid from at least two Javelina Formation azhdarchids (this ‘snub nose’ almost certainly belongs to an unnamed, short-skulled azhdarchid from the same horizon as Quetzalcoatlus).

The famous 1985 'QN' pterosaur, a half-size gliding Quetzalcoatlus northropi and friends, including its designer, the late Paul MacCready (right of middle, in the tie). The model flew successfully multiple times and isn't a bad rendition of an azhdarchid, although many assumptions made in its construction conflict with modern pterosaurology. From MacCready (1985).
Why all the confusion over azhdarchid appearance? Most azhdarchid material known until the late 1990s was either too scrappy to inform artists about life appearance, while the more complete material (the small Quetzalcoatlus species) remained unpublished (and still isn't). The world at large was therefore not able to appreciate azhdarchid anatomy, so any artwork of them required more guesswork than usual. In some cases, entire 'reconstructions' were products of imagination. Not aiding the murky early phase of azhdarchid palaeoart was the transforming nature of pterosaur science which, in the 1980s and 90s, saw much of what we thought we knew about these animals turned on its head. Thus, artists who wanted answers to simple questions like standing postures, wing membrane attachment and so forth weren't always presented with straight answers. 1997 saw a potential change for the better when Unwin and Lü (1997) reclassified the Chinese Maastrichtian ‘nyctosaurid’ Zhejiangopterus linhaiensis as an azhdarchid, but few paid attention to this obscure species when reconstructing 90s azhdarchids, and artwork continued to remain of variable accuracy. The azhdarchid fossil record has not improved fantastically since 1997, only expanding via isolated, scrappy bits and pieces. Their sudden popularity and uniformity of reconstruction has nothing to do with a significantly improved azhdarchid fossil record, then.

Azhdarchids: over 40 Megafonzies of cool!

So, if azhdarchids aren’t new, and they’ve not sent a burst of insightful fossil material our way, why are they now so popular? Perhaps recent reappraisals of their appearance and behaviour have more influence here than anything else. Reconsideration of azhdarchid mass estimates (e.g. Paul 2002; Witton 2008; Henderson 2010; Sato et al. 2010), re-interpretations of lifestyles (Hwang et al. 2002; Witton and Naish 2008, 2013; Carroll et al. 2013) and flight characteristics (Habib 2008, 2013; Witton and Habib 2010) have recast azhdarchids from billboards of flighted animal size to muscular, terrestrially-competent predators and powerful fliers, which just also happened to be giants. This has seen azhdarchids landing ‘major roles’ in palaeo pop media. In the last five years, erect-limbed, terrestrially stalking and quad-launching azhdarchids featuring in the BBC documentary Planet Dinosaur, Atlantic Productions’ Flying Monsters 3D, the 20th Century Fox film Walking with Dinosaurs 3D, the 20,000AD comic series Flesh and recent comics of Teenage Mutant Ninja Turtles, been made into at least two figurines by CollectA, in the upcoming, Steam-released multiplayer game The Stomping Land, in Nathan Carroll's wearable pedagogic puppet form and even a rap. This uptake of the same pterosaur lineage is all the more surprising when you consider the diversity of influences and goals of these projects, as well as the near-infinite sea of fossil species which could take their place. More remarkably, these depictions of azhdarchids aren’t anatomically bad or variable, either: they have large, pointy heads with posteriorly placed crests, long necks, short wing fingers and long limbs. It seems azhdarchids have genuinely penetrated the pop-palaeo zeitgeist.

Azhdarchids in recent comic books, including Teenage Mutant Ninja Turtles and the fabulous 20,000AD series Flesh. Note the far right panel - terrestrially stalked TO DEATH!!! Awesome stuff - should really cover Flesh in more detail here some time. Slide from my TetZooCon talk.

The times, they are becoming very different

I think there's several points of interest here. Firstly, we seem to be witnessing a relative rarity within palaeo pop culture: the indoctrination of a new lineage into the mainstream palaeontological canon. What takes a fossil species from an occasional extra and bit-part player to relative superstardom in the space of a few years? There must be aspects of ‘new’ azhdarchids which have made them more marketable and appealing in short time. And before anyone mentions it, I can vouch for azhdarchid uptake not being overtly pushed by the scientists involved in reinventing them. I've acted as a consultant for three of the projects listed above because ‘new’ azhdarchids were sought after by the media producers, and not as a generic pterosaur expert who pushed his own ideas. The other media, as far as I'm aware, just moved forward with these ideas on their own. 

There is doubtless a myriad of factors making azhdarchids popular - good publicity, a sudden glut of TV and movie interest in prehistoric animals etc. - but I suspect the most important factor is that science accidentally gave azhdarchids a more appealing ‘character’. When we restore fossil animals in art and science we cannot help but impose certain ‘character traits’ into them, and, as with fictitious characters, those with traits we consider desirable are more likely to be popular. 'New' azhdarchids embody everything which is classically cool: they’re original; imagined as assertive, confident animals of great skill and energy; visually interesting and striking; instantly recognisable, as well as being gigantic: metaphorically and physically bigger than us and our problems. Plus, they have that edge of danger: big, predatory species which harvest smaller ones for their own use - let's face it, bad guys and anti-heroes are always cooler than the good guys. In short, it’s not surprising that ‘new’ azhdarchids are popular because they embody the same characteristics as most iconic literary monsters. The traits outlined above could easily apply to H. G. Wells’ Martian tripods (below) or the Star Wars mechanical walkers. Prior to their reinvention, azhdarchids didn’t - and couldn’t - have this appeal, as their appearance was ill-defined, their lifestyles too poorly constrained (skim-feeding? sediment probing? aerial hawking? aquatic pursuit predation? wading?), and much of our science pointed to rather ineffective, flimsy animals. This not only prevented crystallisation of a consistent palaeo pop ‘character’, but also didn't give them much popular appeal.

The uptake of azhdarchids in pop-culture may reflect their recent recasting as stylish, dominating predators of small, defenceless animals, a formula known to strike a nerve with the public - ask H. G. Wells. Do our palaeo pop-culture icons attain iconic status because, like some literary ones, they simply evoke cool characteristics and styles? 
Perhaps more importantly, azhdarchids have - for what seems like the first time - persuaded popular culture to widely depict actual pterosaurs rather than an anonymous set of wing membranes and toothy jaws. That's pretty neat, as it means we're starting to break the notion that different pterosaurs are just minor variants on the same basic animal. I wonder if this applies to pterosaur science too, as research into azhdarchid lifestyles and habits is providing compelling evidence of palaeoecological variation within the group: the concept of shorebird, fish-eating habits applied almost universally to Pterosauria just doesn't work for these guys. With it being increasingly obvious that azhdarchids were doing their own thing, it's easier to start seeing other pterosaurs as potentially having distinctive lifestyles as well. Azhdarchids may be the thin end of the wedge in this respect for both popular and scientific circles.

Of course, no-one can predict how long our current interest in azhdarchids will last, nor what will happen to hypotheses concerning terrestrial stalking, quad-launch and so on. My gut feeling is that these ideas will stand up to scrutiny, but we can never predict what the fossil record or new studies will tell us. Whatever happens, these ideas and the animals they concern have gone some way to superseding generic ‘pterodactyls’ in palaeontological culture, replacing them with a more accurate and detailed appreciation of pterosaur diversity. But what next for azhdarchids? What advances in azhdarchid science are on the horizon? How might these impact their portrayal in popular culture? For that, you’ll have to attend TetZooCon and my talk. Tickets!

References

  • Carroll, N. R., Poust, A. W. & Varricchio, D. J. (2013). A third azhdarchid pterosaur from the Two Medicine Formation (Campanian) of Montana. In: Sayão, J. M., Costa, F. R., Bantim, R. A. M. And Kellner, A. W. A. International Symposium on Pterosaurs, Rio Ptero 2013, Short Communications. Universidad Federal do Rio de Janeiro: pp 40-42. 
  • Habib, M. B. (2008). Comparative evidence for quadrupedal launch in pterosaurs. Zitteliana, 159-166.
  • Habib, M. (2013). Constraining the air giants: limits on size in flying animals as an example of constraint-based biomechanical theories of form. Biological Theory, 8(3), 245-252.
  • Henderson, D. M. (2010). Pterosaur body mass estimates from three-dimensional mathematical slicing. Journal of Vertebrate Paleontology, 30(3), 768-785.
  • Hwang, K. G., Huh, M., Lockley, M. G., Unwin, D. M., & Wright, J. L. (2002). New pterosaur tracks (Pteraichnidae) from the Late Cretaceous Uhangri Formation, southwestern Korea. Geological Magazine, 139(04), 421-435.
  • MacCready Jr, P. B. (1985). The great pterodactyl project. Engineering and Science, 49(2), 18-24.
  • Paul, G. S. (2002). Dinosaurs of the air: the evolution and loss of flight in dinosaurs and birds. JHU Press.
  • Sato, K., Sakamoto, K. Q., Watanuki, Y., Takahashi, A., Katsumata, N., Bost, C. A., & Weimerskirch, H. (2009). Scaling of soaring seabirds and implications for flight abilities of giant pterosaurs. PloS one, 4(4), e5400.
  • Unwin, D. M., & Lü, J. C. (1997). On Zhejiangopterus and the relationships of pterodactyloid pterosaurs. Historical Biology, 12(3-4), 199-210.
  • Witton, M. P. (2008). A new approach to determining pterosaur body mass and its implications for pterosaur flight. Zitteliana, 143-158.
  • Witton, M. P., & Habib, M. B. (2010). On the size and flight diversity of giant pterosaurs, the use of birds as pterosaur analogues and comments on pterosaur flightlessness. PloS one, 5(11), e13982.
  • Witton, M. P., & Naish, D. (2008). A reappraisal of azhdarchid pterosaur functional morphology and paleoecology. PLoS One, 3(5), e2271.
  • Witton, M. P., & Naish, D. (2013). Azhdarchid pterosaurs: water-trawling pelican mimics or "terrestrial stalkers"?. Acta Palaeontologica Polonica doi: http://dx. doi. org/10.4202/app, 5.

5 comments:

  1. So how many more posts until you can link every letter in the work "Azdarchidae" to a different blog post on the clade? From this blog only, of course.

    --Sean

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    1. Hmmm... I think I might struggle quite early on. What do you do with a 'Z' other than 'zounds mister, azhdarchids sure are cool!'?

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    2. "Zoo's worth of Azdarchid Diversity" perhaps? I was more implying to have it link to a post on the subject in general, not one of the letter, but I like the idea of the Azdarchids alphabet...

      --Sean

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  2. Man, is it an exciting time to be a paleo-nerd! I think you could be forgiven for giving yourself a far larger share of the credit than you do here, though perhaps that would be bad form. One question, though: why in the flying Feilongus hasn't the Quetzalcoatlus sp. material seen publication yet? Is it another case of privately held remains closed off to science? I keep seeing off-handed comments referencing the specimen, but have never heard the full story. I feel like there must be some bitter tale waiting to be told there. Also, when it ever DOES see publication, I will be very disappointed if nobody takes the opportunity to name it Q. skybax. Just saying. ;)

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  3. *terrestrially stalked to DEATH*
    I'm curious as to how capable they would be of stabbing prey like that. I've always just kind of drawn them being able to spear the living daylights out of anything short of a suit of heavy plate armor with their "pickaxe-like" heads, but I really have no idea if that's realistic or not.

    I mean, even full plate armor wouldn't protect you from being swallowed whole ( unless it had spikes that were specifically designed to make it impossible to swallow ), but it would be nice to know how hard they could hit, and whether hard impacts could potentially hurt their beaks. Also, what would happen to an unlucky lepidosaur, dinosaur, or heck, time- traveller, who was attacked. Would the azhdarchid kill it first with a stab or a kick? Would the bite force be deadly? Would the peristaltic pressure during swallowing kill it? Would an animal with claws and teeth pose a danger to the azhdarchid's insides, should it be conscious after being eaten? How would it die? Lack of air? Inhalation of gastric acids? Being crushed by the stomach? Being digested alive? Thirst? Consequences of trying to drink gastric acid as if it were water? Falling asleep and drowning?

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