Wednesday 18 May 2016

Quetzalcoatlus: the media concept vs. the science

Background: Javelina Formation forest. Mid-ground: the 4.6 m wingspan, super-famous azhdarchid pterosaur Quetzalcoatlus sp. Foreground: lunch.

As a consultant, the pterosaur I get asked about more than any other is the azhdarchid Quetzalcoatlus. In recent weeks I've been speaking to two completely independent media producers about this animal, and I think just about all my prior TV and film work has involved it somehow, even if not prominently. I suppose Quetzalcoatlus is so popular because it's not just the most famous azhdarchid pterosaur - which are now more popular than ever - but the first animal most people think of as the biggest ever flying creature.

All the pictures, museum exhibitions, sculptures and animations of Quetzalcoatlus suggest it must be a well-understood animal, but it's actually very difficult to provide consultancy on, for several related issues. The first is that the science on the animal itself is unfinished, largely unpublished, and the existing body of work is decades old. The second is that our general understanding of azhdarchid pterosaurs has moved on considerably in the last two decades, and largely without a good grounding of what Quetzalcoatlus actually is. The third, and final, issue is that most parties think Quetzalcoatlus is better understood than it really is, to the point where whole media projects are locked in around it, and consultants are asked to make calls that have little scientific backing. This third point is an important one: 'Quetzalcoatlus the media concept' is a very different beast to 'Quetzalcoatlus the scientific entity'. This can create difficulties when creating programmes, games or artwork of this animal, as the expectations for what can be achieved with Quetzalcoatlus are often beyond what scientists can provide.

In the interests of helping out those who want to use Quetzalcoatlus in their projects, I thought it might be useful to show how 'common knowledge' about Quetzalcoatlus differs from its actual, objective status within 21st century pterosaur science. An important caveat before we go further is that scientific work on Quetzalcoatus is ongoing. A full description and functional assessment is rumoured to be in the works (as, er, it has been for 40 years...) and this will change the way we view this animal tremendously. It can't fail to do so, as the data available on this animal are minimal and the publication of any new details will augment our current situation significantly. In all likelihood this post will be moot, at least in part, when this document is finally published. This piece is being written in May 2016, so please bear in mind that things might have changed if you're reading this at a later date.

The concept. Quetzalcoatlus is a giant azhdarchid pterosaur from Texas, known from substantial remains.


The science. The popular view of Quetzalcoatlus is really a conflation of two taxonomic entities, Quetzalcoatlus northropi and Quetzalcoatlus sp. Both occur in the Upper Cretaceous (Maastrichtian) Javelina Formation of southern Texas*. Q. northropi is currently the only 'officially' named species of Quetzalcoatlus, and is the reason we think this animal was so huge. It's also only known from bits and pieces of a gigantic left wing and cannot be regarded as a well known animal. Do not, if you're a TV producer or whatever, expect to film a room full of real fossils for this thing - any skeleton you see of a giant Quetzalcoatlus is almost entirely reconstruction - still impressive, but nearly all calculation and extrapolation.

*It's worth mentioning that Quetzalcoatlus has been identified outside of Texas, scraps of azhdarchid bones from both North America and Europe being allied to this genus. I suspect that most of these should not be referred to Quetzalcoatlus proper, as they're fairly 'generic' azhdarchid bones and, moreover, we have no criteria for what constitutes Quetzalcoatlus within Azhdarchidae itself (see below). I don't want to discuss these now, however, and only mention them for the sake of completeness. 

Q. sp., by contrast, is much better represented. Several incomplete skeletons are known (an example can be seen below) that collectively give a near complete picture of Q. sp. osteology. Its this material that gives us our familiar image of Quetzalcoatlus: the long neck, the oversize pointy face, the long limbs and so on. Almost all discussions about the detailed anatomy of Quetzalcoatlus pertain to this material, not the giant wing. The Q. sp. fossils are also a key source of the proportional data used in calculating the 10 m wingspan for the giant Q. northropi animal, even though Q. sp. is much smaller - the complete wing metrics of one specimen give a wingspan of 4.6 m (Unwin et al. 2000).

Q. sp. partial skeleton figured by Kellner and Langston (1996).

How the two Quetzalcoatlus species are related to each other, and other azhdarchids, remains critically unexplored and uncertain. It is no exaggeration to say that taxonomic considerations of this important, well-known genus comprise no more than a few sentences in the entirety of technical pterosaur literature. The name Q. northropi was not even erected in a descriptive paper, but as an aside in a brief comment on the likely wingspan of the giant wing specimen (Lawson 1975a). This gave us the northropi name and designated a type specimen (the big wing), and suggested that the smaller specimens were just diminutive, presumably immature versions of the giant species. However, other elements key to species creation - diagnoses, specimen inventories, supporting description or illustrations were not provided, the best alternative being a very short 1975 science paper (Lawson 1975b). Nessov (1991) provided an attempt to diagnose the genus (along with other azhdarchids) but his characters are not useful. Later, Kellner and Langston (1996) suggested that the smaller Quetzalcoatlus skeletons were not juveniles of the giant species, but a distinct species that would be named at a later date. It was this paper that created the 'Q. sp.' moniker, a place-holder for a name we'll perhaps see published in time. Alas, Q. sp. was also created using drive-by taxonomy without justification for separating sp. from northropi, or providing characters to unite these species in a distinct genus among other azhdarchids.

This might all sound like tedious detail irrelevant to reconstructions, media portrayals etc., but the upshot is that the pterosaur community is still largely in the dark about Quetzalcoatlus. We can't really comment on what makes it unique, whether all these bones from Texas should be considered one or two species, how accurate it is to scale up the smaller Quetzalcoatlus to the size of the big wing and so on: that information has not been made public yet. Some specific folks might be able to provide those details, but they are not peer-reviewed 'common knowledge'. Therefore, most researchers (including myself) can only talk about Quetzalcoatlus in terms of the few details that have been published, and fill the rest in with 'generic' details of azhdarchid pterosaur palaeobiology.

The concept. Quetzalcoatlus was like all azhdarchids: a long-necked, long-skulled creature with long limbs.


The science. As alluded to above, we have a basic idea of Quetzalcoatlus sp. appearance, even if the vast majority of it remains unpublished. The core aspects of this animal can be built from data titbits gleaned from different papers: a good description of the skulls and mandibles was provided by Kellner and Langston (1996); Witton and Naish (2008) and Steel et al. (1997) gave some details of the cervical vertebrae, and Unwin et al. (2000) provided measurements for nearly all major limb bones. From this, we can be confident that Quetzalcoatlus sp. is the long-necked, long-faced, toothless, short-winged and gracile-limbed creature we have traditionally associated with the Quetzalcoatlus name. I've attempted a skeletal reconstruction of this 4.6 m wingspan species below using these data: some of the bone anatomy is 'generic azhdarchid', but the basic proportions, skull and anterior neck vertebrae should be OK. This skeletal is the basis for the painting at the top of the post.

Quetzalcoatlus sp. skeletal, using data from Kellner and Langston (1996); Witton and Naish (2008), several other sources of azhdarchid neck data, and Unwin et al. (2000). Yes, it was that long-necked and long-legged.

A question I have much more trouble answering is what Q. northropi looked like. When we see a giant long-necked Quetzalcoatlus in TV shows or comics, we're seeing a hybrid of the two Quetzalcoatlus animals - the anatomy of sp. crossed with the size of northropi. This approach is not without merit: it's consistent with the existing taxonomy of this animal (such that it is), and other pterosaur fossils confirm that some giant azhdarchids were long-necked, perhaps Q. sp-like creatures.

On the other hand, we only have an incomplete northropi wing skeleton to work from. It's widely recognised that pterosaur wings are among the more conservative aspects of their anatomies - great for identifying pterosaurs to specific groups (we have characterised azhdarchid wings, for instance) but above a basic level of taxonomy they don't tell us much about life appearance. It wasn't always this way. When Quetzalcoatlus was found in the 1970s the smaller Q. sp. skeletons provided our only comprehensive insight into azhdarchid anatomy, and thereafter we assumed that Q. sp. typifies the group. However, azhdarchid pterosaur science has progressed considerably in the last two decades and the group can no longer be considered anatomically uniform. Their skulls can be short and broad, long and narrow, and have deep or slender lateral profiles (Witton 2013). They can have cranial crests (Kellner and Langston 1996), but they might not (Cai and Wei 1994). Their necks can be extremely long, or of more typical pterodactyloid lengths (Vremir et al. 2015). Some had stilt-like limb bones, but others had short forelimb anatomy (McGowan et al. 2001). Such variation seems present in the giants as much as their smaller cousins. I don't think we know what an 'average' azhdarchid looked like yet, and Q. sp. should be viewed as representing only one, relatively exaggerated take on azhdarchid anatomy. It historically seemed safe to make Q. sp. a giant version of this form, but that cannot be regarded as the only option today. For all we know, Q. northropi could be a short-armed, short-necked species with a truncated, deep jaw - quite the opposite of Q. sp..

A selection of azhdarchid skull and mandibles. A and B, posterior skull bits of Hatzegopteryx; C-D, Q. sp., E. Zhejiangopterus; F-G, Bakonydraco; H, TMM 42489-2, the Javelina Formation azhdarchid which isn't Quetzalcoatlus. Q. sp. must be regarded as a long-snouted, gracile form: does this also apply to Q. northropi? Image from Witton 2013.
I would be more comfortable with reconstructions of Q. northropi as a giant, scaled-up Q. sp. if we had good reason to believe the two were closely related**. As mentioned above however, necessary work on this has yet to be presented and, as evidence-led scientists, it is not unreasonable to call the situation ambiguous until more data is forthcoming. I suppose one reason we might think northropi and sp. are congeneric is because they're from the same formation. However, the remains of northropi and sp. were not associated, being found tens of kilometres apart (Lawson 1975b), and we have increasing evidence of multiple azhdarchid taxa occurring in the same geological units (e.g. McGowen et al. 2000; Godfrey and Curry 2005; Vremir et al. 2013). Where azhdarchids do coexist, they differ markedly in anatomy and overall form (Vremir et al. 2013). An additional complication is TMM 42498-2, a large, deep-jawed Javelina Formation azhdarchid which is clearly not Q. sp. (bottom panel in the image above). If this represents cranial remains of Q. northropi and not an additional Javelina species (we currently have no way of telling), northropi would look would look very different to our usual depictions.

**I'm expecting people to wonder if Quetzalcoatlus taxonomy has been looked at in detail via cladistic methods. The most complete published assessments I'm aware of are those by Brian Andres (e.g. Andres and Myers 2013) which use seven azhdarchid OTUs, including the two Quetzalcoatlus taxa. The results of such studies remain ambiguous about the affinities of Quetzalcoatlus (Q. sp. and northropi form a polytomy with Arambourgiania). I'd like to see an analysis with more azhdarchid taxa, including some of the more unusual types such as Hatzegopteryx and Montanazhdarcho.

I don't have any real answers or insight on these points. Rather, I'm getting at the fact that our 21st century understanding of azhdarchids and other flying reptiles is becoming complicated, and with our current, superficial insights into what Quetzalcoatlus is and how it's related to other azhdarchids, there may not be one 'right' way to restore northropi. We might be correct to represent it as a giant Q. sp., as per tradition, but we might not.

The concept. Quetzalcoatlus was the biggest animal to have ever flown, even larger than other giant azhdarchids


The science. As with modelling the size of most giant extinct animals, it's difficult to say what giant azhdarchid was the biggest. Q. northropi was certainly up there, recent estimates of its wingspan being in the region of 10 m and predicted body masses of 200-260 kg. But other giant pterosaurs are predicted to be about the same size (see Witton and Habib 2010 for a recent discussion)... and that's about all we can really say. Every giant azhdarchid is represented by scrappy material, so the error bars on any size estimate are large and the calculations themselves are highly sensitive. We would be foolish to use them as anything other than ballpark figures. We can say that Q. northropi was one of the biggest flying animals of all time and, along with other giant azhdarchids, it dwarfed other flying species including most pterosaurs, and all birds and bats. I appreciate some folks will find this lack of clarity frustrating, but that's just how it is: we can't say any more until we understand all the giants - not only Quetzalcoatlus - in more detail. 

The concept. The outstanding flight capabilities of giant azhdarchids allowed Quetzalcoatlus to be a continent-hopping animal that occurred in Europe as well as the USA, although the European bones were given a different name: Hatzegopteryx. Some chap called 'Witton' suggested this.


The science. Thanks, I think, to Wikipedia, I've been confronted several times about suggesting the Romanian giant azhdarchid Hatzegopteryx thambema should be synonymised with Quetzalcoatlus. I feel a bit misquoted on this. Yes, I (and colleagues) mentioned this as a qualified possibility in a 2010 abstract and conference talk (Witton et al. 2010), but as part of a broader, detailed discussion about the need to tighten up giant azhdarchid taxonomy. Specifically, we discussed the three named giant azhdarchids - Arambourgiania philadelphiae, Quetzalcoatlus northropi, and Hatzegopteryx thambema - and stressed issues with their current taxonomy. These issues - hitting some points already tackled here - included the lack of a description and diagnosis for Quetzalcoatlus; the uncertainty over the relationships between Q. northropi and Q. sp.; the scrappy nature and general incomparability of giant azhdarchid fossil remains; their representation by anatomies generally considered unnameable by pterosaur workers, and the identification of several alleged autapomorphies of giant species in other azhdarchid remains.

Holotypes of giant azhdarchids. A, Arambourgiania philadelphiae, B, Q. northropi (humerus only, the other holotype wing elements have never been published) C, the damaged proximal humerus of Hatzegopteryx thambema (humeral head and cranial remains not figured here). From Witton (2013).
Concerning Quetzalcoatlus and Hatzegopteryx, we pointed out that overlapping bits of Q. northropi and Hatzegopteryx (proximal humeri) are similar enough that they could be considered synonymous, but this says more about the use of wing bones for the Q. northropi type material than anything else. As mentioned above, wing bones aren't always that useful in detailed taxonomy. The overlapping bits of Hatzegopteryx and Q. sp. (jaw joints), however, are different enough to demonstrate they are separate taxa. We went on to say that the significance of all this isn't clear because the relationships between Q. sp and Q. northropi are not evaluable at this stage. Our take-home message, then, wasn't that Hatzegopteryx and Quetzalcoatlus are the same thing, but that the diagnoses, validity and relationships of named giant azhdarchids warrant detailed assessment in future. Since writing this abstract six years ago, ongoing work on Hatzegopteryx seems to be supporting its separation from other azhdarchids - more on that in time.

So... how can Quetzalcoatlus be used in art, film, games etc.?

It's clear by now that the way we imagine and depict Quetzalcoatlus as a media construct is very different to its status in science. My take on this animal is about as cautious and conservative as you'll find, and I suppose that's because my experience with azhdarchids in both a research and artistic capacity has frequently found Quetzalcoatlus as a tricky animal to work with. While we can't point to anything being 'wrong' with those older interpretations of Quetzalcoatlus, shifts in our understanding of azhdarchid and other pterosaur science means we can't accept those 40- or 20-year old interpretations of this animal with the same confidence as we used to. Quetzalcoatlus, as a scientific concept, needs modernisation.

Still, my overall goal here is not to be defeatist, rather to simply say what we might and might not be confident about when depicting Quetzalcoatlus. For instance, while Q. northropi is a can of palaeobiological worms, Q. sp. (or whatever it turns out to be) does offer a lot of scope for use in reconstructions and media projects. I frequently feel that these sorts of animals (i.e. the better known mid-sized or small species, not the specrapularly known giants) make interesting enough subjects for artwork and media projects. There's certainly a lot more to work with and say about them, and we can be far more confident in what is being conveyed to the public. Not everything with palaeontological content has to focus on the biggest animals!

Of course, I also appreciate that some projects just can't do without giant azhdarchids. For these, I stress that there are alternatives to Q. northropi which boast the same approximate wingspan, are known from anatomies that provide more insight into life appearance, and have a better grounding in contemporary science. These include the long-necked Jordanian form Ararmbourgiania and its Romanian contemporary, the wide-skulled, robustly-built Hatzegopteryx. Both have interesting stories of discovery and scientific development (for instance, Arambourgiania was actually the first giant azhdarchid on record, not Quetzalcoatlus; and Hatzegopteryx is so chunky that it was initially interpreted as a giant predatory dinosaur) and are palaeobiologically interesting. If these won't do - perhaps for reasons of geography - then consider that unnamed bones of giant azhdarchids are widespread, being known from North America, Europe, Africa and Asia. Although these offer fewer anatomical details than the named taxa, they can also be handled more generally because they don't need to look like a (theoretically) well understood, diagnosed and named species. This means data can be pooled from other finds into a more 'generic azhdarchid' melting pot, and that gives more wiggle room when considering appearance and form.

The take-home here, then, is that Quetzalcoatlus might be the 'best known' giant azhdarchid and the one that everyone wants to feature in their TV shows, films and games, but be forewarned that the scientific status of this animal is rather different to what popular depictions suggest. Moreover, there are alternatives which might be (at time of writing) better understood and just as interesting. If you're planning a TV show, video game or artwork of a giant azhdarchid, remember that there are choices other than the obvious.

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References

  • Andres, B., & Myers, T. S. (2012). Lone star pterosaurs. Earth and Environmental Science Transactions of the Royal Society of Edinburgh, 103(3-4), 383-398.
  • Cai, Z., & Wei, F. (1994). On a new pterosaur (Zhejiangopterus linhaiensis gen. et sp. nov.) from Upper Cretaceous in Linhai, Zhejiang, China. Vertebrata Pal Asiatica, 32(3), 181-194.
  • Godfrey, S. J. & Currie, P. J. (2005). 16. Pterosaurs Dinosaur Provincial Park: A Spectacular Ancient Ecosystem Revealed, 1, 292.
  • Kellner, A. W., & Langston Jr, W. (1996). Cranial remains of Quetzalcoatlus (Pterosauria, Azhdarchidae) from Late Cretaceous sediments of Big Bend National Park, Texas. Journal of Vertebrate Paleontology, 16(2), 222-231.
  • Lawson, D. A. (1975a). Could pterosaurs fly?, Science, 188: 676-678
  • Lawson, D. A. (1975b). Pterosaur from the Latest Cretaceous of West Texas. Discovery of the Largest Flying Creature. Science, 187: 947-948.
  • McGowen, M.R.; Padian, K.; de Sosa, M.A.; Harmon, R.J. (2002). "Description of Montanazhdarcho minor, an azhdarchid pterosaur from the Two Medicine Formation (Campanian) of Montana". PaleoBios 22 (1): 1–9.
  • Nessov, L. A. "Giant flying reptiles of the family Azhdarchidae. I. Morphology, systematics." Vestnik Leningradskogo Universiteta, Seriya 7, no. 2 (1991): 14-23.
  • Unwin, D. M., Lü, J., & Bakhurina, N. N. (2000). On the systematic and stratigraphic significance of pterosaurs from the Lower Cretaceous Yixian Formation (Jehol Group) of Liaoning, China. Fossil Record, 3(1), 181-206.
  • Vremir, M., Kellner, A. W., Naish, D., & Dyke, G. J. (2013). A new azhdarchid pterosaur from the Late Cretaceous of the Transylvanian Basin, Romania: implications for azhdarchid diversity and distribution. PLoS One, 8(1), e54268.
  • Vremir, M., Witton, M., Naish, D., Dyke, G., Brusatte, S. L., Norell, M., & Totoianu, R. (2015). A Medium-Sized Robust-Necked Azhdarchid Pterosaur (Pterodactyloidea: Azhdarchidae) from the Maastrichtian of Pui (Hateg Basin, Transylvania, Romania). American Museum Novitates, (3827), 1-16.
  • Witton, M. P. (2013). Pterosaurs: Natural History, Evolution, Anatomy. Princeton University Press.
  • 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., Martill, D. M. and Loveridge, R. F. 2010. Clipping the wings of giant pterosaurs: comments on wingspan estimations and diversity. Acta Geoscientica Sinica, 31 (1), 79-81.

20 comments:

  1. Very inforamtive post, I really wish we will found more fossils of large Azhdarchids in the future.

    At least we have a new paper on Hatzegopteryx to look forward to.

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  2. It doesn't look like the Unwin et al. (2000) paper you mention in the text as giving most of Q. sp.'s major limb bone dimensions is in your list of references at the end.

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  3. Is it true that neither Quetzalcoatlus has been more thoroughly published upon because some scientist has been sitting on it for several decades but refusing to allow anyone else do the work instead? If that's the case, I don't see why they aren't just as villified as private fossil hunters. They've kept it even more scientifically "invisible" than, say, Pete Larson ever has with his finds. Even the "fighting dinosaurs" he tried to sell at least have publicly available photos.

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    1. It is true, and the reason they aren't villified is because they are now dead. Luckily, it seems that since he has died, the museum has lifted their embargo and Quetzalcoatlus is FINALLY being described by the quite living coauthor Brian Andres (Andres and Langston, 2015 from last year's SVP meeting). Alas, the 2015 abstract is one of those that gives a lot of background info that anyone interested already knows without much actual new data. However, it does give one piece of relevant info- "The giant and smaller morphs of Quetzalcoatlus are recovered as sister taxa and so are closely related as either a single species or sister species."

      Practices like this are depressingly common in dinosaur paleontology. The current big case is Pelecanimimus, described briefly TWENTY-TWO years ago then described in detail in a thesis twelve years ago by a person who is no longer even in paleontology. But despite the fact the thesis will thus never be published, those few people with copies of it refuse to distribute it AND refuse to allow others to photograph it. But hey, they say I'm welcome to come to France and take notes. :| There are similar cases for theropods described in the 1980s from Mongolia and the early 2000's from China. I say if you have gone for a decade after describing a new species, you should rescind any rights you have over the specimen and let the community have access to the data.

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    2. We might want to avoid vilifying people here: I'm sure the chaps working on Quetz for all those years (or who said they were working on Quetz...) weren't deliberately being hoarders or malicious, just over-zealous with their ambitions to work on the specimen and too militant with their embargo. I won't pretend that the circumstances with this animal haven't frustrated certain projects, and I don't think it's unfair to say 40 years is too long to describe a few skeletons. But looking positively, there are real signs of life on the Quetz description. In addition to Brian, I believe Kevin Padian and Jim Cunningham are involved. Hopefully this version of the MS makes it to publication - I know others, by different authors, have fallen by the wayside (see, for example, this TetZoo comment by Chris Bennett: http://blogs.scientificamerican.com/tetrapod-zoology/quetzalcoatlus-the-evil-pin-headed-toothy-nightmare-monster-that-wants-to-eat-your-soul/#comment-1-87C5B20E-9F7D-47DD-A5462231D28E939C).

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    3. I think it's interesting why we're bending over backwards to exonerate Wann Langston. In what way was the Texas Memorial Museum not deliberately hoarding when in your own words, they "placed a strict embargo on the release of information about Quetzalcoatlus" and wouldn't let you or many others even see the thing? If something is museum policy, it's not incidental or accidental, it's by definition deliberate. As for maliciousness, why are big publishers like Elsevier seen as malicious for keeping scientific data behind paywalls when they actually add (some small) value to the data, but Langston somehow wasn't malicious for keeping scientific data behind closed doors and adding no value to it? What's the difference? At least we can pay Elsevier to get the data. It's not like Elsevier employees or even the CEO or shareholders are evil, they just have values that override science. Profit in this case. Yet surely the TMM's (namely Tim Rowe's, according to your link) and Langston's values of prestige or whatever are just as unscientific? So why can't we say "Yeah Wann was a good guy, but his selfishness really set azhdarchid research back decades." If we look upon people like him with some disfavor it might convince those that currently hold specimens in limbo (I forgot Drinker before, which has apparently been stuck in a certain person's office for a decade unavailable for research...) that deliberately hoarding fossils will make them the bad guys in paleo history. We really need to squelch this behavior now, but we need the community's force to do it.

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    4. I don't disagree with your general point, but it's not really bending over backwards to realise that these situations can be complicated, or that we should avoid pointing fingers at specific people without knowing all the facts. Yes, there is an institutional responsibility to getting these specimens out and making them accessible (and the TMM has not done a good job with Quetz on this front), but I'm also aware that these situations can be complicated as goes politics of specimen ownership, discussions over who has the 'right' to work on specimens, issues with analysing the material etc. Reading between the lines with Quetz, the fact the MS was promised for so long, and that waves of people have been attached to it over the years (including Doug Lawson, Wann Langston, Alex Kellner, Chris Bennett and others, and now another team) I wonder if there's more to the story than is publicly known. That doesn't excuse the circumstances of course, but I'm not keen to vilify specific people unnecessarily.

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    5. Having absolutely no real-world connection to the profession of paleontology, I find myself firmly in Mickey's camp, here. I understand there can be complicating factors, but I also think that light public shaming of this "hoarding" practice--or at least a demand for a reasonable explanation--should be deployed in certain situations, such as this Quetz one. The goal should be twofold:

      1) Get the target to back down, accept help, and/or generally stop the unhelpful embargo-ing. At a certain point, you have to realize you're not going to write the damn thing up, so let others do it for you. OR at the very least, provide an explanation as to why Quetz is just not being worked on and why you're not accepting help.

      2) It would (hopefully) send a clear message to the paleo community that this kind of embargoing is not tolerated and maybe you should think twice before locking a specimen in your office and never letting anyone else see it.

      I'm not all about villifying people, but there has to be academic pressure that academics can apply to get results. Just sitting back and saying "well it might be more complicated than we think" then staying silent about it (this is not directed at you, Mark, but paleontology generally) is just the least helpful action.

      There's got to be some kind of middle ground between "this guy's an asshole" and "well, we can't do anything about it."

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    6. I can't...edit posts? Argh.

      Has this issue ever been brought up in academic meetings/conferences? Seems like something the community would be eager to remedy.

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  4. Wow. That skull that may be that of Quetzalcoatlus northropi looks amazingly bulky. Combined with the research on short-necked azhdarchids, it makes me wonder whether northropi was more suited to attacking larger prey than other azhdarchids.

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  5. You managed to draw an azhdarchid facing the camera head-on. Welp, that clinches it: Mark Witton is a paleoart GOD.
    That said, that last part certainly gives me ideas for the cartoon series I'm planning (I don't want to expose too much about it, but I'll give the general gist--it's a story about a boy with an azhdarchid steed traveling across a Dinotopia-esque continent of Cretaceous and some post-Cretaceous survivors); I'm definitely classing the main azhdarchid in mine as an Arambourgiania.

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  6. The sad truth about Late Cretaceous pterosaurs is that even giants are affected by the conservation bias. It now seems possible that we're actually missing a very large diversity.

    Incidently, what do you think of Montanazhdarchps status as a non-azhdarchid? It would account for it's "oddities".

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  7. Hello there Mark Witton. I have a question that although does not pertain to this post, does pertain to pterosaurs; Did anurognathids echolocate or are is that a mammalian trait?

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    1. I'm not an expert in anurognathids, but I'm guessing that they didn't. Anurognathid skulls tend to have large orbits, suggesting that their eyes were unusually big. That doesn't exclude the additional use of echolocation, but it seems rather excessive to be relying on both good vision and echolocation. I guess you'd have to look at the size of their ear bones to be sure.

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  8. After seeing this, I'm starting to wonder if Q. northropi is actually the sister taxa to H. thambena and formed a terrestrial, raptorial giant azhdarchid guild (as opposed to Arambourgiana's giant stork lifestyle)

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  9. After seeing this, I'm starting to wonder if Q. northropi is actually the sister taxa to H. thambena and formed a terrestrial, raptorial giant azhdarchid guild (as opposed to Arambourgiana's giant stork lifestyle)

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    1. Possibly, I have been thinking about it as well. Seeing how flying animals have now limitations from crossing one continent to the other, it seems likely. It would probably make more sense that Hatzegopteryx was not the exception. Of course we will probably never know until a complete specimen is found.

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  10. I have just finished your book on pterosaurs and the section on azhdarchid paleoecology, although brief, really shook my perception of Late Cretaceous ecosystems. I had realized for a while how strange it was that so few medium-sized theropods were known from Late Cretaceous sites, and yet I was stunned by the suggestion that azhdarchids could somehow fill their niche. I can imagine how an individual would have been able to target mammals and dinosaur hatchlings, but if some large species lived in flocks (as some of your depictions suggest), is it possible they could have brought down larger dinosaurs such as hadrosaurs, following herds on the ground and preying upon the old and weak? Granted, their jaws seem better designed to grab bite-size animals and then swallow them whole, but could they have killed prey, for instance, by very intensive pecking? Their long necks might have given them a sufficient reach to strike without being harmed, and they could still lift themselves to the air if prey came charging back at them, possibly making them a very frustrating type of predator. I suppose a mechanical analysis of their skull and neck is necessary to determine whether these body parts could have withstood the shock of such an impact...
    Whatever their lifestyle and their feeding preferences among dinosaurs, the addition of these magnificent creatures to an already impressive cast of Late Cretaceous dinosaur predators brings to mind a host of new scenarios when recreating the lives of these times.

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  11. Rathan Prabhaharan14 April 2017 at 12:55

    Hi,
    My name is Rathan Prabhaharan and I am a 4th year Earth Sciences student. I looking for autapomorphies on pterosaurs for my independent project by going over numerous journal articles. I found them for just over 70 species but I am still struggling. Is there any advice you can give me in regards to find autapomorphies for individual pterosaur taxon? Reply back to my email address: rathanjason@hotmail.com

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