How giant pterosaurs are struggling to take off from the sinking ship of science journalism

This week, it emerged that the giant azhdarchid Quetzalcoatlus was an atrophied, under muscled animal that was weak and inefficient at takeoff, and could only launch through use of running bipedally with flapping wings, headwinds and downward sloping ground. The newly proposed idea of quadrupedal launch, where pterosaurs became airborne via powerful leaping with all four limbs (Habib 2008) is hokum, being the stuff of fantasy and overly zealous application of bat launch strategies to flying reptiles. 70 kg is the maximum mass that these giants and all other flying animals could achieve, and recent discussions that they were considerably more massive (Paul 2002; Witton 2008; Henderson 2010; Witton and Habib 2010) are plain wrong.

At least, that’s what a recent press release by Sankar Chatterjee and colleagues would have us believe. (Above image: the pterosaur launch battleground. At top is a quad launching Hatzegopteryx, a giant azhdarchid; below, is a bipedally launching Quetzalcoatlus using taxiing, headwinds and a slope to become airborne. Hatzegopteryx is from Witton [2013]; Quetzalcoatlus is from Chatterjee and Templin [2004]) Speaking at the Geological Society of America 2012 conference recently held in Charlotte, N.C., Chatterjee (of the Museum of Texas Tech University; most notable within recent pterosaur research for his contribution of windsurfing tapejarids to the Attenborough pterosaur documentary) and colleagues outlined why he considers much of the recent discussions of giant pterosaur flight dynamics to be flawed in a short presentation, and decided to disseminate their ideas further through the public press. Although the press reports for this story have been relatively widespread, the response from pterosaur researchers to this release has been generally negative, largely because the claims do little to address the recent developments and hypothesis shifts within pterosaur flight studies and largely parrot the findings of Chatterjee and Templin’s 2004 paper on pterosaur flight. Pterosaur.Net’s own Mike Habib, one the key modern researchers on pterosaur flight, offered this take on the release:

“Unfortunately, this looks like the argument comes down to ‘but we got a different answer in 2004!’ Yes.  We know, and for five years I've explained why it is probably wrong.  Oh well.”

Chatterjee et al.’s abstract and press release do not explain why the many arguments supporting pterosaur quad launch (see here and here, for a start) are problematic or why arguments and methodologies to estimate relatively high masses for pterosaurs (here) are incorrect. Instead, they’ve decided that such scientific rigour doesn’t matter, and gone straight into informing the public that giant pterosaurs took flight in the way described in their presentation, and that all other opinions on the matter are wrong.

By bigging up their abstract rather than a peer-reviewed publication in which their methodological details and discussion are explained in detail, Chatterjee et al. have given the impression that their work is more scientifically credible than it actually is. Science journalists have lapped the release up, presumably because giant pterosaurs are cool, but they have not mentioned the lack of a detailed peer-reviewed study behind the findings, nor (in the majority of cases) bothered to find out what other palaeontologists make of the story. This is not the first time this sort of outreach has happened. The proceedings of other conferences and un-reviewed articles have given us infamous press stories such as the ‘Triassic kraken’, vampire pterosaurs, and the suggestion that all dinosaurs were aquatic. And these are just examples from recent memory.

As a scientist concerned about effective and accurate scientific outreach, I find this sort of journalism very worrying. I have no problem with off-kilter ideas like those proposed by Chatterjee et al., but their desire for press attention without applying appropriate scientific rigour is extremely concerning. They have not documented their studies in a scientific paper, sought the opinions of other experts in peer review to construct a scientifically sound hypothesis and news piece. Instead, they went straight from the ‘idea’ phase of their project to media broadcasting, which, as I see it, has three effects. Firstly, it risks misleading the public if their ideas fail to meet scientific scrutiny (most of the ideas mentioned thus far in this article are guilty of this, and I strongly suspect the same is true of the Chatterjee et al. story). Secondly, it undermines the integrity of the scientists behind the story. The idea that “any publicity is good publicity” does not apply to scientists. Within academic circles, you become “the guy who went public with [crazy idea]”, which doesn’t do your reputation, or that of your institution, any favours. Thirdly and perhaps most importantly, such practises undermine science generally. It’s no wonder that palaeontology is often viewed as a speculative and unsubstantiated discipline when a lot of our press work concerns unsubstantiated, often ‘fringe’ or highly controversial ideas being presented as credible hypotheses. This only creates confusion among people as to what the leading hypotheses on given topics are or, when press stories have gaping holes in logic (e.g. the Triassic kraken, aquatic dinosaurs) show scientists as bumbling, foolish individuals incapable of using common sense.

This is a serious problem which we, as scientists and scientific communicators, need to address. Many people are generally sceptical of scientists and their conclusions, concocting up ideas of scientists in scaremongering conspiracies for grant money, or seeking media attention to justify their employment at publically funded museums and universities. The manner in which scientists frequently present unsubstantiated work to non-academics does little to help restore our reputation with these individuals. While it’s of fairly trivial concern whether the public, or anyone for that matter, knows the ins-and-outs of pterosaur launch, all scientists need to think about the broad perception of science by the public. Scientists researching our many severe, modern crises need to be taken seriously, and press reports that expose incomplete or shoddy scientific work negatively impact this perception. Fairly or not, many people, tar all scientists with the same brush (for proof, check out the comments section on any science story publicised by the Daily Mail). We should be working to enhance the reputation of science among the public so that scientific opinions on critical issues like our on-going losses of biodiversity, climate change, sustainability of our lifestyles, energy conservation, and other real, genuine problems are trusted and taken seriously. Scientists leaping for the press with hypotheses that have yet to be suitably tested only present scientists as attention seekers, incompetent or both, and we cannot afford to perpetuate this idea further.

Of course, the fault does not only lay with the scientists. Science journalists also need to raise their game, becoming more circumspect when following and writing up of press stories, noting the state of the research involved, gauging its context within its field and, perhaps in some cases, ignoring clearly bogus, fringe reports entirely. I have worked with a great number of people involved in the scientific media who clearly do not have any interest in science beyond their job, and these are the worst people to be trying to turn the sometimes complex hypotheses of scientists into digestible material for laymen. As Brian Switek shows on a daily basis at Dinosaur Tracking, you become an exemplar science journalist not by just being a deft writer, but you have to give a crap about science too. Failure to fact check and presenting ideas inaccurately is miscommunication, which is clearly an enormous failing for an individual employed to dissemination of information.

In short, we need to stop thinking about scientific outreach as purely an exercise in getting the most attention possible to our research or science news articles. These short-term goals are damaging to science as a whole, which is what science communicators are meant to promote. Science communication is an opportunity to educate non-academics with new and exciting results of good scientific practise that have helped develop our understanding of the world and our place within it. We should take the responsibility that this task requires fully and seriously if we want our scientific voice to be listened to.

References

• Chatterjee, S. and Templin, R. J. 2004.  Posture, Locomotion and Palaeoecology of Pterosaurs. Geological Society of America Special Publication, 376, 1-64.
• Habib, M.B. 2008. Comparative evidence for quadrupedal launch in pterosaurs. Zitteliana, B28, 161-168.
• Henderson, D. M. 2010. Pterosaur body mass estimates from three-dimensional mathematical slicing. Journal of Vertebrate Paleontology, 30, 768-785.
• Paul, G. S. 2002. Dinosaurs of the Air: The Evolution and Loss of Flight in Dinosaurs and Birds. John Hopkins University Press, Baltimore, 472 pp.
• Witton, M. P. 2008. A new approach to determining pterosaur body mass and its implications for pterosaur flight. Zitteliana, B28, 143-159.
• Witton, M. P. 2013. Pterosaurs: Natural History, Evolution, Anatomy. Princeton University Press. [In press]
• Witton, M. P. and 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, e13982.

It’s dumb, it’s awesome, it’s… Our lives with pterosaurs, part 2

If you’re wondering what’s going on here, or if you’re looking at the right blog, it’s probably because you haven’t read this yet. And yes, we are stooping this low.

 

Pterosaurs in the modern day! What would it be like if some pterosaurs survived the K/T extinction to coexist amongst our modern biota and in modern environments? Such are the questions we're attempting to answer here. Just to remind you, the only pterosaurs under direct scrutiny in these posts are azhdarchids and nyctosaurids as they seem to be the only pterosaur lineages that were present at the terminal Cretaceous. We spent a lot of the last post discussing how we may try to exploit pterosaurs for our own benefit, and in this concluding post we’re going to consider how we may succeed at coexisting with wild pterosaur populations. (Adjacent image: when stork-like animals go wrong)

NOTE: The Blogger upload system has been a real pig this evening, and formatting this post has been nothing short of a nightmare. Apologies in advance for any choppy bits of text or other issues. I have tried to correct errors as I go, but please let me know if I've missed any. 

Meeting the neighbours

Humanity would probably bump into wild pterosaurs fairly often. Azhdarchid pterosaurs, in particular, achieved very wide distributions in the Cretaceous, being absent only from Antarctica (Witton and Naish 2008; Ösi et al. 2011; see map, above, for the distribution of azhdarchid fossils. From my Ph.D. thesis). Azhdarchid fossils show very strong ties to terrestrial environments,either being preserved in continental freshwater deposits and, when they do occur in marine sediments, they tend to be components of mixed terrestrial/marine biotas (adjacent graph is a sexier version of the same data presented in Witton and Naish [2008] on this topic. I’ve not updated it with new data since then, but the statistics will not have changed significantly to my knowledge). Their distribution across the globe suggests they were versatile animals capable of living in different habitats and climates, and their palaeoenvironmental signature hints that they would preferentially frequent terrestrial settings. Modern azhdarchids, then, may be fairly familiar sights to us if they were around today.

We may even find that some single azhdarchid species were found all over the globe. Some of the recent findings on their flight ability are rather arresting, with the 10 m span giants seemingly capable of flight speeds exceeding 100 kph (62 mph; Witton and Habib 2010). Mike Habib's recent SVP talk suggests that they could remain aloft long enough to travel almost halfway round the world in one sitting (Habib 2010) and, to paraphrase him directly, (imagine this being said VERY LOUDLY for full effect. Those who know Mike will understand why), geographic boundaries would mean nothing to these guys. This may mean that the sort of provincialism we see in some modern fliers may not apply to these forms and, indeed, cautionary words on the implications of this have been said with regard to azhdarchid systematics.

We may not find ourselves quite so acquainted with nyctosaurids, however. Their fossils are generally rarer than those of azhdarchids and, to my knowledge, largely constrained the Americas. Their rarity is of particular interest because Nyctosaurus, perhaps the best known of all nyctosaurids, occurs in the Smoky Hill Formation of Kansas, a deposit that has also supplied over 1000 Pteranodon specimens since 1872. I’m not sure how many Nyctosaurus specimens there are around the world, but I get the impression that it may be dozens, not hundreds or thousands (please let me know otherwise if I’m wrong, though). Assuming that this does not reflect other sampling or preservational biases, it seems that nyctosaurids were simply rather rare animals. Their remains, unlike those of azhdarchids, are also found exclusively in deep marine deposits, suggesting they spent much of their time away from land. Nyctosaurid anatomy agrees with their lack of landlubber status: the loss of the three, small manual digits used in walking and embarrassingly small legs do not suggest proficient terrestrial abilities. By contrast, the development of ossified tendons in the forearms of some nyctosaurid specimens (Bennett 2003; Frey et al. 2006) suggests that they put tremendous, continuous strain on their wings, and the wings themselves are super-long and probably very glide-efficient. The impression one gets, then, is of highly volant creatures that probably spent almost their entire lives in the skies over seas and oceans, so perhaps only sailors and fishermen would regularly see them if they were alive today.

Garbage monsters

In developed countries where little or no primary habitats remains, our modern azhdarchids may spend much of their times in rural areas, as this is probably the closest approximation of their natural habitat, and would, perhaps, provide the largest amount of live prey. The feeding habits of azhdarchids have been controversial since they were identified in the 1970s, but, in what is probably the only thorough exploration of their feeding habits to date, Darren Naish and I concluded that they were most likely ‘terrestrial stalkers’, long-legged predators of relatively small animals sought out in sparsely vegetated settings (Witton and Naish 2008). This idea may not be unfamiliar to many of you: not only have Darren and I waxed lyrical about it repeatedly in various blogs and lectures, but it’s now been immortalised on on TV and even in excellent, excellent comic book format (you can also download the full paper for free). Accordingly, I won’t go into details here, but, for the uninitiated, the seemingly proficient terrestrial abilities and long jaws and neck of azhdarchids seem well suited for hunting small game on land and, often, poorly adapted for anything else. The bulk of modern azhdarchid diets may not be too dissimilar to their Mesozoic ancestors, as these ancient forms were likely to primarily dine on small reptiles, amphibians and mammals that would appear, superficially at least, not too different from their modern representatives. Of course, modern azhdarchid diets would lack a certain non-avian dinosaur flavour, and that would presumably be substituted by various mammal species.

Azhdarchid jaws are generalised enough that we cannot rule out some ocassional bouts of scavenging, and it would be silly to ignore the importance of carrion feeding to some modern azhdarchid analogous, the ‘giant’ storks. Some of these birds – particularly the larger Leptoptilos species (e.g. the adjutant and marabou storks) – frequently forage on carrion (Kahl 1987) and, because we humans are disgusting slobs who do not dispose of our garbage properly, they have expanded their taste for lousy food to leftovers on rubbish tips. Other, more familiar birds are also keen rubbish raiders: I’m sure we’ve all seen local crows and gulls riffling through bins or splitting open refuse sacs. I see no reason why azhdarchids would not develop the same behaviours, so we may find some of them colonising urban areas and living off our waste. Perhaps this would mean that some modern azhdarchid species would be fairly resistant to the current global species decline, as the route to evolutionary success nowadays seems to mostly revolve around living off our garbage (well, it is the only resource we’re not running out of). (Image, above, shows said exploitation of waste in action)

If wild azhdarchids did take foot in urban settings, encounters with them may be a little daunting for human residents. As we discussed in the last post, pterosaurs seem to have increased their average body size over time, so later forms were much larger than the earlier. Perhaps we’d feel fairly confident stopping smaller (2.5 m span) animals from spreading rubbish all over our driveways, but would we feel the same about 4, 7 or 10 m span animals? Perhaps not. Plus, did I mention that these pterosaurs may have been gregarious? Several azhdarchid localities have yielded associated azhdarchid skeletons (Lawson 1975; Cai and Wei 1994) or very abundant azhdarchid remains (Nessov 1984; Ösi et al. 2005), suggesting that they were at least tolerant of each other, or perhaps even hanging around in little groups. All told, in this hypothetical world of pterosaurs, we’d probably need to seriously rethink our philosophy on garbage disposal. Probably best to keep the cat in, too.

They can eat my trash, so long as they don’t eat me

Speaking of modern pterosaur diets, an enormous elephant in the room needs to be acknowledged: would we be on the menu? This is a legitimate question, and not because we’re used to Tinseltown pterosaurs having a taste for human meat. Some azhdarchids were so enormous that they could consume people-sized prey (by which, I mean small adults, not just children). We don’t have particularly extensive fossils of giant azhdarchids to test this with, but we do have a key component for answering this question: a giant pterosaur skull fragment comprising the jaw joint and some bones from the roof of the mouth (shown on the left, in ventral view, in the image below). This belongs to the 10 m span Hatzegopteryx, one of the largest azhdarchids known, and is notable for its unusually robust construction of stout bony struts and enormous jaw condyles. By doubling its width we can attain minimum estimate of the complete jaw width, revealing a staggering maw 500 mm across (Buffetaut et al. 2002, 2003). (Image, below, shows the mirrored Hatzegopteryx jaw skull element. The ventral braincase and posterior jaw region of Thalassodromeus is shown for comparison and to scale. Thalassodromeus, by the way, has a jaw of 160 mm width and 700 - 800 mm long. Hatzegopteryx was mucking huge).

We should remind ourselves at this point that we’re a) talking about the minimum width here, so there's possibly room for a little more expansion; and b) these are, so far as we can tell, animals capable of flight, and yet had skull widths that many large dinosaurs would be jealous of. As with many pterosaurs, the asymmetrical nature of the jaw condyle would deflect the lower jaw laterally when opened so that much of the 500 mm jaw width could be used for swallowing food. The posterior palatal region is also highly vaulted, so there is additional swallowing space in the dorsal region oral cavity, too. Combine this with the likelihood of a large gulf between the mandibular rami occupied by distensible gular pouch (known from several exceptionally-preserved pterosaur specimens), and it seems more than likely that Hatzegopteryx could fit a person into its throat.

After that, of course, you’d need to be moved down the long neck, a length up to 3 m if we assume that the giants had necks of comparable proportions to those of smaller azhdarchids. Unfortunately for us, we have good evidence that pterosaur throat tissues were highly elastic and capable of encompassing large prey, so we may slip through an azhdarchid oesophagus without issue. The preservation of a recently-devoured fish in a complete juvenile Rhamphorhynchus specimen reveals just how large some pterosaur prey items were, and how stretchy their throats must have been to accommodate it (see detail of the trunk region of this specimen, below. After Wellnhofer 1975). The specimen in question was preserved in the process of digesting a fish that – as preserved – occupies 60 per cent of its trunk length, but may have been even larger as the anterior end had already been partially digested (Wellnhofer 1975). Pterosaurs, then, may have had small bodies, but they weren't afraid of packing their meals in. Our previous discussions on how giant pterosaurs could support our weight in flight have obvious connotations here, too: if one could support our weight externally, there seems little reason to suggest they couldn’t internally. We may fill their bellies, but we wouldn't impede their locomotion in doing so.

The outlook isn’t looking promising for us, then. Larger members of the populace may be a bit too massive to comfortably digest, but leaner or smaller folks may well be at risk. In any case, giant azhdarchids would be best avoided. If we did encounter one, would our chances of being eaten be high? Perhaps it would depend on context of engagement. On open ground, the 2.5 m long limbs and powerful muscles of giant azhdarchids would almost certainly chase us down and, hey, let’s not forget: they can fly. It's hard to outrun an animal that can fly fast enough to get a speeding ticket on most roads. We may be safe if we could get to cover or a cluttered setting, as the giant azhdarchid bauplan is hardly suited to moving through narrow confines or probing crevices. Without that, though, I don’t fancy our chances. Azhdarchids of this sort may be quite difficult to deal with too, short of simply killing them. Troublesome bears or cats can be moved far enough away from populous areas that they won’t bother people again, but we’d be hard pressed to stop relocated azhdarchids from simply flying back to wherever we caught them. The more I think about it, the more it seems that large azhdarchids would actually be quite a dilemma for us, and one that would probably see most of them being shot. All told, maybe it’s best for us all that they're extinct.

On that bombshell, then, I think that’s enough of this craziness for the time being. Hopefully, someone, somewhere, will have taken something useful from these posts and, if nothing else, we finally have a picture of a cowboy quad-launching a giant pterosaur. With that, I think my work here, and perhaps the respectable portion of my career, is finished. 

References

• Bennett, S. C. 2003b.  New crested specimens of the Late Cretaceous pterosaur Nyctosaurus. Palaeontologische Zeitschrift, 77, 61-75.
• Buffetaut, E., Grigorescu, D. and Csiki, Z. 2002. A new giant pterosaur with a robust skull from the latest Cretaceous of Romania. Naturwissenschaften, 89, 180-184.
• Buffetaut, E., Grigorescu, D. and Csiki, Z. 2003. Giant azhdarchid pterosaurs from the terminal Cretaceous of Transylvania (western Romania). In: Buffetaut, E. and Mazin, J. M. (eds.) Evolution and Palaeobiology of Pterosaurs, Geological Society Special Publication, 217, 91-104.
• Cai, Z. and Wei, F. 1994. Zhejiangopterus linhaiensis (Pterosauria) from the Upper Cretaceous of Linhai, Zhejiang, China. Vertebrata PalAsiatica, 32, 181-194.
• Frey, E., Buchy, M. C., Stinnesbeck, W., González, A. G. and Stefano, A. 2006. Muzquizopteryx coahuilensis, n.g., n. sp., a nyctosaurid pterosaur with soft tissue preservation from the Coniacian (Late Cretaceous) of northeast Mexico (Coahuila). Oryctos, 6, 19-40.
• Habib, M. B. 2010. 10,000 miles: maximum range and soaring efficiency of azhdarchid pterosaurs. Journal of Paleontology, 30, 99A-100A.
• Kahl, M. P. 1987. An overview of the storks of the world. Colonial Waterbirds, 10, 131-134.
• Lawson, D. A. 1975. Pterosaur from the Latest Cretaceous of West Texas: discovery of the largest flying creature. Science, 185, 947-948.
• Nessov, L. A. 1984. Pterosaurs and birds of the Late Cretaceous of Central Asia. Paläontologische Zeitschrift, 1, 47-57.
• Ősi, A., Weishampel, D. B. and Jianu, C. M. 2005. First evidence of azhdarchid pterosaurs from the Late Cretaceous of Hungary. Acta Palaeontologica Polonica, 50, 777-787.
• Ősi, A.,Buffetaut, E. and Prondvai, E. 2011. New pterosaurian remains from the Late Cretaceous (Santonian) of Hungary (Iharkút, Csehbánya Formation). Cretaceous Research, 32, 4556-463.
• Wellnhofer, P. 1975. Die Rhamphorhynchoidea (Pterosauria) der Oberjura-Plattenkalke Süddeutschlands. Palaeontographica A, 148, 1-33, 132-186, 149, 1-30.
• Witton, M. P. and 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, e13982.
• Witton, M. P. and Naish, D. 2008. A reappraisal of azhdarchid pterosaur functional morphology and paleoecology. PLoS ONE, 3, e2271.

Our lives with pterosaurs, part 1

Not many mornings ago the lovely Georgia Maclean-Henry and I were discussing the the topic of 21^st century pterosaurs. Not, you understand, as a discussion of whether the reports of late-surviving, cryptid pterosaurs are genuine (they almost certainly aren’t, for reasons discussed in Darren Naish’s assassination of this idea), but a hypothetical premise that pterosaurs were commonplace components of our modern fauna, and what they would be like to live with. Though obviously speculative and completely juvenile, I thought this may be fun to blog on and discuss with others, so feel free to chime in at the end of the post with your own ideas. Who knows, we may even learn something in the process. (Image, above, shows what we're all now thinking).

Before we get going, though, some ground rules. Aside from the fact that we’re ignoring pterosaur extinction in this discussion, we’re basing everything else on fact as much as possible. For instance, we’re not ignoring the extinctions of specific pterosaur groups: if they went extinct before the terminal Cretaceous (when pterosaurs as a whole got the evolutionary chop), then they can’t exist in the modern day. Pterosaurs are also the only animals we’re hauling into the Modern: the biosphere is otherwise exactly as it is now, so there are no tyrannosaurs or anything running around as well. Also, the goal here is to consider pterosaurs as real animals, not hyper-aggressive movie monsters, so we don’t need to pay any attention to their Modern interactions with people in virtually all Silver Screen outings (which invariably boil down to said people being attacked and/or eaten) and start with a clean slate of ideas. Got that? On we go, then.

UPDATE: 24/04/12
Just one last rule, following on Mike Taylor's comment, below. I'm also focusing on pterosaurs as we know them in the fossil record, not as we may twist them through selective breeding or other genetic tampering. I guess this is an exercise in simply crashing pterosaurs into the Recent, considering what basic pterosaur palaeobiology would lend itself to in our modern world.

Roll call

The first part of this exercise, of course, is to determine what pterosaurs we would have running around today. Which lineages were present at the end of the Cretaceous that could, potentially, have survived until Recent times? Because pterosaur fossils are found within spitting distance, geologically speaking, of Tertiary rocks we assume that the last of their kind died out in the same mass extinction event that ruined the weekends for 75 per cent of life 65 Ma (Buffetaut et al. 1996), but the majority of pterosaur types were not witness to this event. Pterosaur faunas of the uppermost Cretaceous are almost entirely dominated by azhdarchids, the often gigantic, toothless and long-necked forms made famous by the likes of Quetzalcoatlus and Hatzegopteryx (see sketch, above, for a general guide to their appearance). These famous genera, incidentally, are some of the last pterosaurs we find in the fossil record, so giant pterosaurs are very much in for our consideration here. An incomplete nyctosaur humerus (if you’re not familiar with nyctosaurs, think Pteranodon, but weirder) from Mexico is the only record of non-azhdarchid pterosaurs in Maastrichtian strata (that is, name of the time interval representing the last 5 million years of the Cretaceous, 70-65 Ma), compared to literally dozens of azhdarchid occurrences (Price 1953). The pterosaur fossil record is noted for its incompleteness and preservational biases (Butler et al. 2009), but their reduced diversity at the end of the Cretaceous may not be an artifact of the fossil record as the number of pterosaur-bearing rock units at this time is relatively high, but diversity remains low. In short, then, while we may be able to identify dozens of different pterosaur groups across their evolutionary history, it seems that only the azhdarchids and nyctosaurs would have any hope of meeting us in the modern. (Image, below, shows a phylogenetic tree of pterosaurs using the major clades of Lü et al. [2010] mapped across time. The squiggly line shows the number of pterosaur-bearing rock units throughout the Mesozoic [borrowed from Butler et al. 2009] From my book).

With 65 million years separating us from the last pterosaurs, it is not unreasonable to assume that they may have developed into rather different forms by the time modern man appeared. Or would they? Evolutionary stasis spanning 9 – 10 Ma has recently been proposed for several non-pterodactyloid pterosaur clades (Lü et al. 2012) and, although admittedly suggested by rather fragmentary remains, several pterodactyloid lineages also do not appear to change dramatically over longer time frames. This may be true for azhdarchids as much as anything else: a vertebra representing the oldest known azhdarchid is known from Berriasian rocks of Romania (140 Ma) (Dyke et al. 2010) and looks, so far as I can see, no different from the vertebrae of Maastrichtian forms. Note that azhdarchid necks are very derived compared to those of other pterosaurs, so this comparison of their cervical anatomy suggests that the group was already fairly ‘evolved’ very early on in the Cretaceous. Maybe, then, modern pterosaurs would not be so dissimilar from the forms we know in the fossil record.

Bird brains

What sort of behaviour would we expect of our modern pterosaurs? To best answer this we may want to assess some likely basic aspects of pterosaur physiology and neurology, as this may provide  an insight into how active and intelligent they may have been. There’s scant discussion of pterosaur physiology in pterosaur literature, but their flight adaptations, erect carriage (in at least pterodactyloids, and probably some non-pterodactyloids too), insulating fuzz and relatively large brains all seem to correlate with modern animals that have elevated metabolisms. Pterosaur brains are known from specimens spanning much of their phylogenetic range, and they all seem fairly bird-like, but especially so in later forms (e.g. Witmer et al. 2003; image and caption, below, from this study). There are some differences, such as the pterosaur flocculus (the region of the brain primarily dedicated to motor coordination) being relatively enormous, (perhaps because the muscle-laden wing membranes of pterosaurs were being directly controlled and shaped during flight, requiring some extra computing power [Unwin 2005]), and bird brains are, on the whole, a little larger, but they are otherwise fairly similar. 

It may not be unreasonable, then, to predict that all pterosaurs – including our hypothetical modern ones – would be active, fairly intelligent beasties that, with warm bodies and big brains to fuel, may spend much of their time foraging. This leads us to a further analogy with birds: the requirement for lots of food does not sit well with flight, as a full belly is more mass to shift about. Hence, pterosaurs – like birds – may have dumped their waste as often as possible, presumably in the same form of acidic paste that common to all archosaurs. Such waste can be very damaging to architecture and car paint, so the existence of giant pterosaurs dropping vast quantities of crap on our cool stuff is not an appealing one. Plus, we’ve all been hit by stray bird guano on occasion, which is unpleasant enough, but imagine the same experience when the offending animal is several hundred times the size…

My pet pterosaur, and pterosteaks

As with most things in life, it probably wouldn't be long before the economic potential of Modern pterosaurs was tested. Could we farm them for meat and eggs, or breed them as household pets? Pterosaurs would probably be lousy sources of food for several reasons. The amount of meat offered from pterosaur carcasses is tiny compared to their overall size, providing minimal returns to pterosaur farmers for the space required to rear them. Pterosaurs have tiny, tiny bodies, with their edible soft tissues tightly concentrated around them. Even the biggest azhdarchids probably only had bodies 70 cm long (Witton and Habib 2010) with around 60 kg of flight muscle (Paul 2002), despite standing tall enough to look into a first floor window. Ornithocheiroids are even more disproportionate, with torsos barely longer than their humeri (near-enough the shortest bones in their wings). Some pterosaurs may offer better options, such as the relatively long bodied ctenochasmatoids, but they were long gone before the KT boundary, and therefore out of the game here. 

Keeping ourselves stocked with pterosaurs may require a lot of careful planning as their development times appear more extended than we're accustomed to with modern livestock. Because pterosaurs lay parchment-shelled eggs like most modern reptiles, it’s assumed that they required similarly long incubation periods of two or three months (Unwin and Deeming 2008). Once hatched, it seems that neonate pterosaurs did not rocket to full adult size like modern birds (a trait we’ve artificially enhanced in poultry to have large, fully-grown chickens within weeks of hatching), instead slowing their growth rates once they reach half size (Chinsamy et al. 2008). It's predicted that, for some pterosaurs, this threshold may take several years to reach (Bennett 1995; Chinsamy et al. 2008) As such, we could be looking at several years between pterosaur generations, which is a little on the slow side for big business. We don’t know much about pterosaur clutch sizes or reproductive rates, so it’s not clear how many animals you’d need to sustain a harvestable, breeding population but, regardless, it seems that you’d need a pretty substantial operation to get any profit out of space-demanding animals with awkward reproductive mechanisms.

So, pterosaurs would probably make for lousy food sources, but what about pets? It would certainly be cool to keep your own little azhdarchid that you could take out for a flap, train to fetch the morning paper and perform tricks, but the ‘little’ part may be a problem. Pterosaurs are said to demonstrate Cope’s Rule, the controversial idea that the average body size of individuals within a given lineage will increase over time (Hone and Benton 2007; see graph from this study, above, showing the increase in average pterosaur wingspans over time). Whether you agree with the notion of Cope’s Rule or not, it’s hard to ignore the steady increase in average pterosaur body size throughout the Mesozoic, leading to the smallest known Maastrichtian taxon (the oddly-proportioned Montanazhdarcho) being 2.5 m across the wings. A 2.5 m span may seem small compared to its 10 m span contemporaries but, for a homeowner, it would still be far too large to have in the house. Standing upright, said diminutive azhdarchid would have a shoulder height of over a metre and, with its long neck, be nearly as tall – if not taller - as you. That’s hardly a little animal, and probably one that would scare the bejesus out any other pets you have, and may even see them as potential lunch. Perhaps best to leave the pterosaur wrangling to zoos, then.

The biggie: could I ride a pterosaur to work?

Almost certainly the most important consideration in this concept: were pterosaurs strong enough fliers that we could saddle them up fly them places? Well, possibly.

Pterosaur.Net regulars are no doubt aware that some pterosaur workers now think that pterosaurs launched quadrupedally, using their powerful flight muscles to propel themselves into the air (Habib 2008). Part of the rationale for this idea is the strength of the forelimbs compared to the hindlimbs, as the launching limbs tends to be proportionally large in any flying vertebrate you care to look at over a certain mechanical threshold. As with most animal skeletons, it seems that the pterosaur forelimbs came equipped with large mechanical safety factors to accommodate for any atypically heavy loads that may be placed on the limbs. The humeral safety factors against bending in the largest azhdarchids – which we would possess in the Modern in our hypothetical scenario here, remember – are around 2.5 – 1.8, depending on how heavy you consider the animal to be between 180 - 250 kg (Witton and Habib 2010). Thus, the pterosaur skeleton could take weight of a person without crumpling, but could it take off? It seems so: Marden (1994) calculated that a giant azhdarchid would find launch no more strenuous than a 1 kg vulture, suggesting that one could, theoretically, take on the extra burden of a person on its back. Perhaps only relatively small folks would be suitable pterosaur jockeys to reduce the strain as much as possible but, hey, that’s still something, right?

This is not the end of the story, however. While the azhdarchid may be able to sustain flight with a jockey when flapping vigorously, it would not be able to endure this indefinitely. Mike Habib predicted for our 2010 study that a giant would have a few minutes of burst flight, tops, before it had to rest in a gliding phase. To avoid merely landing at the end of this, an alternative source of lift would be needed, and this is where a potential fly in our ointment appears. Long distance travel for azhdarchids was probably achieved by soaring (Witton and Habib 2010), which would be reliant – as it is with modern birds and bats – on climbing to high altitudes (many thousands of metres in some cases) on uplifts of air before gliding on. This would be a significant problem for our jockeys. Mammals are far less tolerant of hypoxia than birds (and, perhaps, by extension, pterosaurs) and, at altitudes that even little birds like sparrows are alert and lively, mammals are comatose (Faraci 1991). Hence, to fly with azhdarchids we may have needed to curb their flight styles a bit, keeping them at lower altitudes and, presumably, making more frequent use of areas of uplift. Alternatively, we supply them with oxygen tanks and warm clothing to keep them alive, but this all adds weight and reduces our azhdarchid's flight ability. Hmm... perhaps this is more complex than we thought.

Gosh, look at the time. There’s a lot more we could mention about riding pterosaurs, but I think we’ll stop there for now. This has already gone on too long and I’ve not even covered the most exciting bit: living alongside wild pterosaurs. Would we be potential pterosaur prey? Could they be pests of annoyances to us? All things to be discussed soon...

References

Buffetaut, E., Clarke, J. B. and Le Lœuff, J. 1996. A terminal Cretaceous pterosaur from the Corbiéres (southern France) and the problem of pterosaur extinction. Bulletin de la Societe Geologique de France, 167, 753-759.

Butler, R. J., Barrett, P. M., Nowbath, S. & Upchurch, P. 2009. Estimating the effects of the rock record on pterosaur diversity patterns: implications for hypotheses of bird/pterosaur competitive replacement. Paleobiology, 35, 432-446.

Bennett, S. C. 1995. A statistical study of Rhamphorhynchus from the Solnhofen Limestone of Germany: year-classes of a single large species. Journal of Paleontology, 69, 569-580.

Chinsamy, A., Codorniu, L. and Chiappe, L. 2008. Developmental growth patterns of the filter-feeder pterosaur, Pterodaustro guiñazui. Biology Letters, 23, 282-285.

Dyke, G., J., Benton, M. J., Posmosanu, E. and Naish, D. 2010. Early Cretaceous (Berriasian) birds and pterosaurs from the Cornet Bauxite Mine, Romania. Palaeontology, 54, 79-95.

Faraci, F. M. 1991. Adaptations to hypoxia in birds: how to fly high. Annual Review of Physiology, 53, 59-70.

Habib, M.B. 2008. Comparative evidence for quadrupedal launch in pterosaurs. Zitteliana, B28, 161-168.

Hone, D. W. E. and Benton, M. J. 2007. Cope’s Rule in the Pterosauria, and differing perceptions of Cope’s Rule at different taxonomic levels. Journal of Evolutionary Biology, 20, 1164–1170.

Lü, J., Unwin, D. M., Jin, X., Liu, Y. and Ji, Q. 2010. Evidence for modular evolution in a long-tailed pterosaur with a pterodactyloid skull. Proceedings of the Royal Society B, 277, 383-389. 
Lü, J., Unwin, D. M., Zhou, B, Chunling, G, and Shen, C. 2012. A new rhamphorhynchid (Pterosauria: Rhamphorhynchidae) from the Middle/Upper Jurassic of Qinglong, Hebei Provine, China. Zootaxa, 3158, 1-19.

Marden, J. H. 1994. From damselflies to pterosaurs: how burst and sustainable flight performance scale with size. American Journal of Physiology, 266, 1077-1084.

Paul, G. S. 2002. Dinosaurs of the Air: The Evolution and Loss of Flight in Dinosaurs and Birds. John Hopkins University Press, Baltimore, 472 pp.

Price, L. I. 1953. A presença de Pterosáuria no Cretáceo superior do Estada da Paraiba. Divisão de Geologia e Mineralogia Notas Preliminares e Estudos, 71, 1-10.

Unwin, D. M. 2005. The Pterosaurs from Deep Time. Pi Press, New York, 347 pp.

Unwin, D. M. and Deeming, D. C. 2008. Pterosaur eggshell structure and its implications for pterosaur reproductive biology. Zitteliana, B28, 199-207.

Witmer, L. M., Chatterjee, S., Franzosa, J. and Rowe, T. 2003. Neuroanatomy of flying reptiles and implications for flight, posture and behaviour. Nature, 425, 950-953.

Witton, M. P. and 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, e13982. 

Does Air Density Make a Difference?

This is essentially a cross-post from H2VP (with some additions)

One thing I have been asked with some regularity is whether or not a somewhat denser Mesozoic atmosphere, particularly in the Cretaceous (compared to the modern one), could explain the giant size of Late Cretaceous pterosaurs or large dinosaurs.  In short, the answer is: probably not.

There is a reasonably good body of information regarding atmospheric composition during the Mesozoic.  During the Cretaceous, both oxygen and carbon dioxide levels rose slightly, and the total atmospheric density would have been slightly greater as a result - but the difference would have been relatively mild for large vertebrates.

Here is an example of a paper published on the effects of Cretaceous oxygen concentrations on plants: http://jxb.oxfordjournals.org/content/52/357/801.full, and there is a manuscript examining the effect of paleoatmosphere conditions on insects: http://jeb.biologists.org/content/201/8/1043.full.pdf.  There is a relatively recent paper on the Late Cretaceous atmosphere and its potential relationship to mass extinction as well: http://jxb.oxfordjournals.org/content/52/357/801.full

As you can see, plants and insects probably felt the effects of slightly higher oxygen and carbon dioxide concentrations, and indeed the insects of the Cretaceous included some relatively large species, as would be expected.  A slight increase in atmospheric density would have relatively little impact on the maximum size of dinosaurs or pterosaurs, however, and there is not actually any need for an extreme explanation for their size, anyway - despite being larger than living animals with similar lifestyles, none of the giant dinosaurs exceeded the expected maximum size for a walking animal, and no pterosaurs exceeded the limits for biological flight.  Quite a few pterosaurs exceeded the estimated limit for continuous flapping flight in a vertebrate animal (limit is roughly 25-30 kg, give or take), but that only means that they could not flap continuously over long distances and would have switched to soaring flight for long trips; it does not forbid them from flying.

There are three reasons why changes in atmospheric conditions have greater impacts on insects than vertebrate flyers.  First, the tracheal system that insects use for respiration is highly sensitive to oxygen partial pressure.  Second, since insects are typically small, they are often highly reliant on unsteady aerodynamics, which are much more sensitive to air density than steady dynamics.  Finally, insects are almost purely aerobic flyers, while many vertebrates can utilize some degree of anaerobic power (in large flying vertebrates, anaerobic power dominates).  Using anaerobic flight muscle provides a very large burst of power, without using oxygen, after which the muscle quickly fatigues.  Large vertebrates can therefore flap for short bursts, followed by periods of gliding, even when oxygen levels are low.  This option is typically unavailable to insects.

The London Pterosaur ExTrAvAgAnZa!!!1!! in full glory

This is a hard post to write. It may be the big latte I’ve just drunk or possibly a sugar low, but there’s a genuine buzz about my fingers as I type this. In short, not too far away from the little café I’m perched in now sits an enormous pterosaur exhibition that the University of Portsmouth amigos David Martill, Bob Loveridge, an army of volunteers and I put together over the last year and a half. It’s been up for several days on London’s Southbank after being installed through the night of Sunday the 20th of June (and I mean through the night: we literally didn’t sleep for 2 days) and will remain there for another week or so. We'll be taking it all away with another all-nighter on the 5th of July. Having a huge display that you personally constructed - and based on your own PhD work - on the Southbank is a little bit exciting, and the fact that I got to meet Princess Anne, attend a Royal Society Convocation (attended by numerous Royals, including Queenie herself) and have numerous people wanting to shake my hand on a job well done while standing around our work is pretty durned good.

Anyway, enough gushing: below is a little taster of what we’ve got in store for Londoners over the next week and a half. You can see the final of our BBC videos, documenting the installation of our flying animals, here and, at the top of this post and beneath this text, there's a series of photographs taken from the exhibition itself. At some point in the near future, I'll post more images detailing the development of the exhibition and some of the concepts we went through in designing and manufacturing the display. Once again, thanks to everyone who helped us out with this project and, for those helping us on the stand over the next few days, thanks in advance. Again, it'd be great to see some Pterosaur.Netters there, too: entry is free and, behind us, you've got the entire Royal Society Summer Science Festival to run around (and there's some really cool stuff in there, too. Obviously not as cool as our display, though). Details can be found here. Anyway, enough blurb: on with the images. Click to enbiggen.


The whole schebang: two giant walking azhdarchids, three flying jobbies, a considerable number of display boards and some bemused onlookers.


Mike O'Sulivan and Luke Hauser, dedicated pterosaur groupies and student volunteers, pose next to our life-size male Pteranodon image. Note that while Pteranodon is big, both Mike and Luke were in the loo when height was being dished out*. Hence, it may appear a little smaller in life.

*Only joking, guys. You're both fine, upstanding examples of the male form. I mean, look at Luke there. Look at Mike lean. Pwhoar.


Our female azhdarchid, who became known as Quetza, grabs Dinner, the hapless baby titanosaur. Kids love this. And by 'love' I mean 'question why we're so heartless'. And by 'question why we're so heartless' I mean 'strongly object'.


The head of Bamofo, our big male azhdarchid. While there's plenty of goofs on him, Bamofo is my favourite model: part azhdarchid, part Terminator, part King Kong: all foam.


The guys next to our gallery of pterosaur busts. Pteranodon and Tupandactylus are taking great interest in Luke's hair, and Coloborhynchus is about to take a chunk of Irish from Mike's arm.


What giant pterosaurs look like when you view them from above. If I was feeling trite, I'd call this a 'pterosaur eye-view'. Thankfully, I'm feeling stern and not in the mood for such things, so I won't.



Two of our flying models, complete with RAF roundels to commerorate the 70th anniversary of the Battle of Britain. I genuinely had nothing to do with them and, being suspended 10 m in the air and well out of reach, I've decided to learn to like them.

The Brotherhood of Leathery Wings goes to London

I’ve got a habit of withering on for ages when blogging, but that can’t be the case today: in a few short hours I’m off to London to install the University of Portsmouth/Royal Society ‘Pterosaurs: Dragons of the Air’ exhibition with my colleagues, Dave Martill and Bob Loveridge, along with a bunch of student labourers/slaves/groupies that we keep with us at all times. The last few weeks has seen us working like Japanese beavers trying to get everything finished (hence the lack of posts here) but, happily, we’ll be on display on London’s Southbank from the 25th of June to the 4th of July. More specifically, we can be found spread between the interior and exterior of Royal Festival Hall (see map, taken from a presentation I gave ages ago on the exhibition, below), not too far from Waterloo train station and the London Eye.


We’ve got 5 (count ‘em) giant azhdarchid models (two of which are standing on the ground as the world’s first Haenamichnus-inspired parasagittal terrestrial azhdarchid models), 13 pterosaur busts representing a broad sweep of their diversity, a life-size Pteranodon to have your photograph taken alongside and more information on pterosaurs than you could shake a stick at. It was a mammoth amount of work and special praise should be given to the students and other volenteers who put in so many hours in exchange for no more than a few pints of beer and, bizarrely, Southern Comfort and Coke (you know who you are). Simply put, these chaps were the cogs that helped our leathery-winged machine run smoothly, so they deserve considerable amounts of kudos, presents and praise.

You can meet our workforce at the exhibition and, in addition, we'll have several tamed pterosaur experts to chat to while you’re there. Along with myself, Dave and Bob, the likes of Darren Naish and Andre Veldmeijer will be dropping by to discuss all things pterosaurian. Two pterosaur-researching postgraduates from UoP, Richard Hing and Steven Vidovic, will also be on hand. The whole event, part of the biggest-ever Royal Society Summer Science Festival, is totally free to enjoy and should make for a great day out. It’d be fantastic to see some of the Pterosaur.Net readership there.


Right, I have to dash, but more on the exhibition will be posted when I get back. In the meantime, please enjoy two new images of giant azhdarchids penned back in January to advertise the exhibition. The image at the top shows our big male, Bamofo, terrorising some baby tyrannosaurus and, adjacent to this text, is the graceful Mistress swooping over a mudflat with bathing sauropods. See you all in London!

Embarrassing questions on Quetzalcoatlus

You can’t queue up at a supermarket checkout nowadays without being bombarded by celebrity lifestyle magazines. They glare at you from the impulse-buy shelves with paparazzi shots of stars looking flabby, pregnant, boozy or unhappy and garish, block capital headlines scorn celebs for revealing their mortal flaws. There is probably a deep-seated psychological reason to their popularity, perhaps reflecting the desire people have for gossip or reassuring somewhat insecure readers that it’s OK, people with stars on Hollywood Boulevard aren’t perfect either. The thing that strikes me, though, is that a lot of the people splashed all over the front pages of these rags have very little substance behind their fame, becoming famous because they took they posed semi-nude for a tabloid newspaper, are related to someone else in the public eye or appeared on telly for five minutes on a reality TV show. These are the empty celebrities, the ones that you assume have some reason for being known but, when investigated in more detail, are actually quite devoid of substance. It’s rare that these tabloid-fodder achieve international fame: to do that, you’ve at least got to be associated with an internationally-released product or hung-out in high-profile political circles. In some respects, then, becoming a real international household name requires a little more substance than your local, lower-grade celebrities. Talent, though, is handy but not strictly necessary.

There are definitely fossil animals that are the equivalent of A-list celebs, the sort of critters that every five year-old knows and that press releases strive to mention, no matter how tangential their work is to them, to gain more kudos. They’re the animals that the public know and love, the likes of Tyrannosaurus, Triceratops, woolly mammoths and sabre-toothed cats. Typically, these animals do have some substance to them: while their taxonomy may be confused or controversial, they definitely ‘exist’. Some pterosaurs are in this club too, with Pterodactylus (or probably ‘pterodactyls’) or Pteranodon being at the top of the list, and Quetzalcoatlus, everyone’s favourite superpterosaur, just behind (detail of a new image above). Thing is, though, Quetzalcoatlus may be a fraud. Yes, that’s right: there may be so little substance to its existence that its status as a household palaeontological name is undeserved: it’s a local celeb masquerading as a big shot. That’s controversial stuff and, no doubt, several of you have just sprayed your monitor with coffee shot through your nose at the very idea of such a thing. But mop up that liquid, dry the screen off, and we’ll see why I’m suddenly being so nasty to one of the cornerstones of Azhdarchidae.


Giant, yes; diagnostic, maybe not
As I’m sure you all know, Quetzalcoatlus stems from the Maastrichtian Javelina Formation of Texas. Remains of several animals that would be referred to this genus were found from 1972 – 1974 and were briefly described by their discover, Douglas Lawson, in 1975 (Lawson 1975a). Quetzalcoatlus was erected in the same year (Lawson 1975b) with fragments of a giant left wing (including a famous complete humerus, TMM 41450-3; see image, above) being used as the holotype for the type species, Q. northropi Lawson, 1975b. A bunch of smaller individuals that were represented by substantially more complete remains were discovered at the same time and initially referred to the same species (Lawson 1975a, b) but, later, were said to be sufficiently distinct from Q. northropi to deserve their own species (Kellner and Langston 1996). Pending their complete description, however, Kellner and Langston simply called them ‘Q. sp.’ for their work on the Quetzalcoatlus skull.

That all looks above board on the surface, but it doesn’t take much digging to find several massive holes. Firstly, despite the wealth of material that has been referred to it, neither Quetzalcoatlus or Q. northropi have ever been given a rigorous taxonomic definition*. To my knowledge, only Nesov (1991) has had a stab at a Quetzalcoatlus definition but his listed characters are either not unique to Quetzalcoatlus or of questionable validity, so his work is not really useful here. This leaves us without a diagnosis and, accordingly, we simply cannot know if Q. northropi is a valid species or not. What’s more, with Q. northropi being the type species of Quetzalcoatlus, the entire genus must go if the former is sunk.

*You could get away with this sort of stuff in the 1970s, but it’s much harder to be taxonomically slack nowadays. The ICZN (the body that regulates naming of zoological specimens) has recently tightened its rules considerably to make sure that new taxa come with proper holotype allocation, diagnoses and all other due practises (e.g. article 16, International Commission on Zoological Nomenclature 1999), so messes like the one under discussion here should – in theory – eventually become a thing of the past.

In my eyes, this is quite a real possibility. Pterosaur limb elements aren’t normally named because they are not considered diagnostic at generic or species levels: taxa that are based on limb elements alone have been considered nomina dubia by later authors. ’Santanadactylus’ spixi - a set of wrist bones - and Palaeornis cliftii - an isolated humerus – have both fallen into this trap (Unwin 2003; Witton et al. 2009). Unless Q. northropi is unusually distinctive, it’s possible it may be binned too. Adding more concern to this worryfire is that, so far as I can see, the Q. northropi humerus doesn’t look that different from other giant azhdarchid humeri (e.g. Padian and Smith 1992; Buffetaut et al. 2002) and the existence of these other giants nullifies the possibility of using size as a diagnostic feature (though this would be dodgy anyway). The other Q. northropi elements are so scrappy that they’re probably of very little taxonomic utility and preclude the use of limb element proportions in a diagnosis, too. Call me cynical if you like, but it looks like this could be an uphill struggle to me.


The plot thickens
There’s more. With no definition for Quetzalcoatlus, the referral of the Q. sp. material (including that depicted above, from Kellner and Langston 1996) to this taxon is also questionable. The Q. sp. material is what people refer to when talking about the detailed anatomy of Quetzalcoatlus, but we need to be careful: there has never been any justification printed for the allocation of Q. sp. to Quetzalcoatlus: we’ve just been told it’s similar to Q. northropi and can therefore be placed in the same genus. Thing is, Hatzegopteryx, Arambourgiania and Zhejiangopterus are pretty similar animals to Q. northropi too, so why can’t the Q. sp. material been popped in one of these genera instead? You can't argue taxonomic provinence in this instance, either: it's highly likely that there is more than one azhdarchid genus in the Javelina Formation (see my thoughts on this here), so you can’t suggest allocation of Q. sp. to Quetzalcoatlus through association alone.

To be clear, I'm not saying that Q. sp. itself is of questionable validity - whatever you want to call it, Q. sp. is definitely a valid, diagnosable species, I’m just iffy about its allocation to Quetzalcoatlus at present. Note, however, that the story continues outside of material referred to Quetzalcoatlus, too: the status of Hatzegopteryx may also hang in the balance. I don’t have time to go into that now, though.

So, what next?
The resolution of all this is, in my view, quite straightforward. Eagle-eyed readers may have read between the lines of this post and realised that, despite it’s fame, popularity and unearthing almost 40 years ago, there is almost nothing written or illustrated of Quetzalcoatlus. The issues highlighted here will not be resolved without this data and, frankly, a few good photographs and descriptions of Q. northopi would give all the information we need to get started. There is, in fact, a bit of an elephant in the room about Quetzalcoatlus and, foolish though it may be for a bloke looking for a job in the pterosaur corner of palaeoindustry to be so outspoken, it should be flagged up. Without mentioning any names, the Texas Memorial Museum has placed a strict embargo on the release of information about Quetzalcoatlus until the full monographic description has been properly published. This has been promised since at least the 1980s (Langston 1981; Kellner and Langston 1996) and, in the meantime, getting access to the material seems to be extremely difficult. I asked to see the material back in 2006 and was told no. Colleagues of mine have asked the same, and got the same answer. The few friends of mine that have seen the specimens are sworn to secrecy and, if they want to publish even itty-bitty snippets of information about them, they have to ask permission first.

If you ask me, this is all a bit rotten. The Society of Vertebrate Paleontology’s ethical mission statement states that vertebrate palaeontologists of the world are here to:

1. To advance the science of vertebrate paleontology throughout the world;
2. To serve the common interests and facilitate the cooperation of all persons concerned with the history, evolution, ecology, comparative anatomy and taxonomy of vertebrate animals, as well as the field occurrence, collection and study of fossil vertebrates and the stratigraphy of the beds in which they are found;
3. To support and encourage the discovery, conservation and protection of vertebrate fossils and fossil sites;
4. To foster the scientific, educational and personal appreciation and understanding of vertebrate fossils and fossil sites by avocational, student and professional paleontologists and the general public.
   

From the SVP Constitution, Article 12, Code of Ethics.

Aside from the point 3 in this list, it seems that the decades-long embargo on the Quetzalcoatlus material isn't really in keeping with these guidelines. I mean, I get embargoes. I get 'gentlemen's agreements' about publishing rights. But 40 years to publish a specimen description while simultaneously being very cagey about giving access to the material? Seriously guys, what's going on? I'm not sure there's quite enough ground here to go stampeding to the SVP ethics committee or anything, but when is this material going to be properly published and freely available to see?

References

• Buffetaut, E., Grigorescu, D. and Csiki, Z. 2002. A new giant pterosaur with a robust skull from the latest Cretaceous of Romania. Naturwissenschaften, 89, 180-184.
• International Commission on Zoological Nomenclature. 1999. International Code of Zoological Nomenclature (4th Edition). The International Trust of Zoological Nomenclature, 1999.
• Kellner, A. W. A. and Langston, W. Jr. 1996. Cranial remains of Quetzalcoatlus (Pterosauria, Azhdarchidae) from Late Cretaceous sediments of Big Bend National Park. Journal of Vertebrate Paleontology, 16, 222-231.
• Langston, W. Jr. 1981. Pterosaurs. Scientific American, 244, 92-102.
• Lawson, D. A. 1975a. Pterosaur from the Latest Cretaceous of West Texas: discovery of the largest flying creature. Science, 185, 947-948.
• Lawson, D. A. 1975b. Could pterosaurs fly? Science, 188, 676-677.
• Nesov, L. A. 1991. Gigantskiye lyetayushchiye yashchyeryi semyeistva Azhdarchidae. I. Morfologiya, sistematika. Vestnik Leningradskogo Gosudarstvennogo Universiteta. Seriya 7, 2, 14-23.
• Padian, K. and Smith, M. 1992. New light on Late Cretaceous pterosaur material from Montana. Journal of Vertebrate Paleontology, 12, 87-92.
• Unwin, D. M. 2003. On the phylogeny and evolutionary history of pterosaurs. In: Buffetaut, E. and Mazin, J. M. (eds.) Evolution and Palaeobiology of Pterosaurs, Geological Society Special Publication, 217, 139-190.
• Witton, M. P., Martill, D. M. and Green, M. 2009. On pterodactyloid diversity in the British Wealden (Lower Cretaceous) and a reappraisal of “Palaeornis” cliftii Mantell, 1844. Cretaceous Research, 30, 676-686.

Scruffy pterosaurs by scruffy people

As regular readers of the Pterosaur.Net blog will know (erm… assuming we have any), I work at the University of Portsmouth cobbling together models of giant pterosaurs out of bits of styrofoam, metal, fake fur and anything else that happens to be lying around. We’re supported by the Royal Society because, this coming June, we’re headlining their London Summer Science Festival. Being on a grander scale than anything the RS has pulled off before, our pterosaur models are booked to be displayed on the world-famous Southbank, right outside Royal Festival Hall and visible to thousands of people. The BBC have taken an interest in this and decided to record the progress on our project in a series of films: the first can be found here, the second here and, yesterday, the third was posted here.

Hosted by yours truly in the most forlorn looking vest seen this side of a Die Hard movie, it discusses the finer details of our pterosaur models: eyes, fur, colour and all that jazz. Also featured are Bob Loveridge, resident UoP Eyeman and chief techie-chap, and some of my slaves/groupies – sorry, student volunteers (Luke Hauser and Chris Callaghan) who’re working on their own contributions to the project. You can also spy a full-size Thalassodromeus bust in the background of one shot, but what you can’t see is it’s dual sided nature. Bored with making perfect pterosaurs over and over again and knowing full well that some pterosaur fossils show all sorts of interesting pathologies (Bennett 2003), I decided to render our Thalassodromeus rather visually-imparied in it's left eye, a consequence of a dirty-big scar across its eye and a cataract. Check him out: if anyone ever made a Bond film set in the Mesozoic, this thing would definitely be a baddie.


Dinner the baby titanosaur, momentarily freed from the azhdarchid jaws that normally hold him, acts as scale: he's about 1.2 m long. He's also been overhauled in recent weeks: he's no longer green, has fewer obvious joins and has undergone facial reconstruction surgery. He still has the same fantastic fashion sense, however and, apparently, a taste for chocolate (adjacent photo by Sarah Brown). Those wondering how sauropods grew so big so fast, take note.



Reference

• Bennett, S. C. 2003. A survey of pathologies in large pterodactyloid pterosaurs. Palaeontology, 46, 195-196.