Tuesday, December 13, 2011

Pterosaurs in the Carnegie

People keeping up with my main blog, the Archosaur Musings, will know that about a month ago I hopped over to Pittsburgh to do some pterosaur work with the esteemed Mike Habib at the legendary Carnegie Museum. Since then I've been furiously blogging about the huge number of dinosaurs that are on exhibition.

However, there's also a much-better-than-you-might-expect collection of pterosaurs on display and I took some time to blog my way through these. Since this has gone utterly unmentioned on P.net, it seemed I should rectify this. Sadly I'm just going to link back to all the other posts, but there's pretty pictures and stuff, so that should help with the disappointment right?




Friday, November 25, 2011

Scarfe's snout

This is a shameless re-post from the Musings, but really rather an appropriate one. Not only is it about a brand new pterosaur from the UK, but the post (and indeed new pterosaur) come courtesy of Dave Martill. Dave supervised the PhD research of Lorna steel, Darren Naish and Mark Witton, so in one way he has quite a claim to Pterosaur.net. Take it away Dave:

Cuspicephalus scarfi from the Late Jurassic Kimmeridge Clay Formation of Dorset is one of those irritating fossils. It was clearly a beautiful animal, with long, slender jaws and fine teeth that would have made it look impressive. It is without doubt a cracking fossil, displaying a near perfect right lateral outline, with only a little bit of the dorsal rest missing. OK, it is sad that the lower jaw and rest of skeleton is missing, but in the UK, this specimen is the best thing since the second specimen of Dimorphodon was discovered in the Lower Jurassic in the mid 1800s. But despite its near completeness for a British pterosaur skull, it is not entirely clear where it belongs in the grand scheme (or schemes), of pterosaur phylogeny. It appears to be a pterodactyloid similar to Germanodactylus on the basis of its single NAOF and straight dorsal border, but when compared with Darwinopterus, its affinities become less clear cut. Sure, it isn’t Darwinopterus, but it isn’t Germanodactylus in the strictest sense either. Dave Unwin thinks it might lie close to the base of Dsungaripteroidea, and I am inclined to agree, but caution that this is based mainly on the nature of its crest… not a good criterion given the distribution of elongate fibrous-looking crests in Pterosauria.

[caption id="attachment_6550" align="aligncenter" width="500" caption="Cuspicephalus skull. From Martill & Etches, in press"][/caption]

Cuspicephalus was discovered by Steve Etches. Known to most UK vertebrate palaeontologists, Steve collects fossils exclusively from the Kimmeridge Clay of Dorset and has built up a renowned collection housed in the Museum of Jurassic Marine Life (MJML) in Kimmeridge, Dorset. Steve discovered Cuspi on the wave cut platform in Kimmerdge Bay and reckons that one more tide would have destroyed it. Steve has found several other pterosaurs in the Kimmeridge Clay, some of which are represented by associated remains attributable to an animal close to Rhamphorhynhcus, and currently being examined by PhD student Michael O’Sullivan. A few specimens in Steve’s MJML have been identified as representing a germanodactylid by DMU, and it is possible that these elements are from the same animal as Cuspicephalus: clearly Steve needs to get out and find the complete skeleton.
The name Cuspicephalus is derived from the sharp pointed nature of the skull in lateral view, and I suspect in dorsal view too, but Kimmeridge Clay fossils are rather 2D to tell. The specific epithet honours Gerald Scarfe CBE. Scarfe is known to most UK citizens as the artist who provided the caricatures for the intro to the extremely popular satirical TV series Yes Minister and follow up Yes Prime Minister. Both were excellent lampoons of the UKs higher civil servants and mainly incompetent elected politicians. Globally Scarfe is known to several generations of Pink Floyd fans as the artist behind The Wall (album, film and more).

[caption id="attachment_6549" align="alignright" width="226" caption="Margret Thatcher as drawn by Gerald Scarfe. Courtesy Dave Martill"][/caption]

To readers of certain newspapers and periodicals Scarfe is loved or laothed for hard hitting political caricatures, and in particular those of British Prime Ministers and other notorious world leaders. Many were reproducible in daily newspapers, but others remained within the underground literature for reasons of decency (check out Rupert bear ****ing Mary Whitehosue with the Pope watching on). One cartoon of Scarfe’s that stands out is a caricature of Margaret Thatcher, an ex British Prime Minister who Scarfe Portrayed as a Tory blue, saggy-breasted pterodactyle, and therefore it seemed only fair that he should be honoured. Scarfe’s cartoon might have the number of fingers wrong, and he might have followed the Frey and Riess model for the orientation of the pteroid, but we all know he got the colour right.

Pip pip

Monday, November 21, 2011

Water Launching Pterosaurs

This post is a cross-post from H2VP (again), but should be of interest to pterosaur.net readers.

I gave two presentations at SVP this year, and the second (in the form of a poster) was on pterosaur water launch. Specifically, I presented a model that Jim Cunningham and I have worked out for a plausible water launch strategy in Anhanguera. If you want to see what this might have looked like, turn your cursors here to Mark Witton's website. The relevant illustration is on the far right.

I will not give too much detail on this presentation at the moment, as it is shortly bound for PLoS ONE. However, here are some of the highlights:

- A bipedal water launch model appears to fail for Anhanguera (and other pterosaurs), just as the bipedal model fails for their terrestrial launch.

- A quadrupedal water launch model, in which the wings are the primary mechanism used to free the animal from the surface and to push along the surface to reach launch velocity, seems to check out for all of the parameters we can currently estimate with any confidence.

- Anhanguerids probably took multiple hops across the water surface to launch, but our calculations suggest that most of the actual energy expenditure was spent escaping the surface tension.

- Our model makes testable predictions about comparative anatomy of pterosaurs, which is important when building these kinds of models from fluid theory. Our model predicts that water launching pterosaurs should have features such as: warped deltopectoral crests or dp crests with flared distal ends, enlarged scapulae, extreme disparity between forelimb and hindlimb lengths, and reinforced scapulo-notarial joints. We have a more extensive list of features that can be shared a later date, but the primary note here is that these predicted features do indeed seem to show up mostly in marine pterosaurs, and less so in terrestrial taxa, so there is a least a loose, pattern-matching form of validation that can be applied to our hypothesis.

We hope to have animations and a full paper out on the topic of pterosaur water launch in the near future (next few months) so stay tuned!

Wednesday, November 2, 2011

Aurorazhdarcho - a Jurassic azhdarchoid

Just a short post on this little fellow. I don't generally like blogging on new taxa as a lot of other people cover them and there's generally not much that can be said from an outside perspective that's not in the paper. I don't have much to add in that respect here either, but this is a nice thing for me to see out as I've seen the specimen knocking around in Dino Frey's office on a number of occasions over the last few years while being assured it would be described 'soon'. Well, now it is out and Aurorazhdarcho is born.

The specimen is obviously in superb condition (photos above and below lifted from Frey et al., 2011) though the head and neck are gone. Still, an impression remains on the sediment to show where they originally lay and given an idea of their original size and shape which is rather nice.

The most interesting thing though is the identification of this as member of the azhdarchoids. This most derived of pterosaur clades are otherwise known only from the Cretaceous, though a Jurassic origin is to be expected if (and for some, this is a big if) you accept that Germanodactylus is a dsungariptid and that this clade is the sister-taxon to the azhdarchoids. Certainly it has a few features that are unique to the group (that huge hindlimb for starters) and this identification looks good to me (though I have to confess I have yet to read the paper in full detail), though as ever with a specimen like this, the lack of a head is a real shame.

Frey, E., Meyer, C.A. & Tischlinger, H. 2011. The oldest azhdarchoid pterosaur from the Late Jurassic Solnhofen Limestone (Early Tithonian) of Southern Germany. Swiss Journal of Geosciences in press.

Wednesday, October 5, 2011

Dinosaur Revolution: Anhanguera

This is actually a cross-post from H2VP, but it seems quite relevant here, as well. Those of you that watched episodes 3 and 4 of Dinosaur Revolution (which aired exactly one week ago) saw the sequence focusing on the large pterodactyloid pterosaur, Anhanguera. This was one of the sequences I had the most input on, so I thought it might be fun to chat briefly about some scientific background that inspired the sequence.

Parental care in pterosaurs?
The sequence opens with a mother Anhanguera visiting her nest of offspring, whom she then kicks out of the test for their first flights (these end poorly for the first two babies, but the "hero" character survives to fly another day). We have relatively little evidence regarding the specifics of parental care in pterosaurs. What we do have is good evidence that pterosaur babies were able to fly very early in life, and that the eggs were of a soft-shelled structure, which implies that the eggs were buried in foliage rather than brooded in the manner of birds. This manner of egg-laying alone does not tell us much about parental care - "leathery" eggs are laid by some taxa that do guard young (crocodilians) and many that do not (most squamates, though some of those guard nests and young, too). However, the fact that baby pterosaurs were so well developed, and likely able to fly early in life, is at least suggestive that there was not an extended period of parental care. Baby pterosaurs probably set off from the nest relatively early (possibly immediately). Check out Darren Naish's blog post from February on pterosaur babies and eggs for more.

Pterosaur Locomotion
There are three major types of motion shown in the sequence: ground locomotion, launching, and flight. As it turns out, the first two of these are really the same "mode" of movement. After speaking with David Krentz, he and I thought it would be interesting to show the baby Anhanguera hopping in a saltatorial fashion. There are no trackways that show this mode of locomotion in pterosaurs, but we also don't have any trackways that can reliably be mapped to ornithocheirids yet, and the limb proportions of ornithocheirds like Anhanguera are consistent with a saltatorial method of movement. This observation is noted in the paper that Mark Witton and I published in 2010. It is published in the highly acclaimed, open access journal PLoS ONE, and is freely available here.

The takeoff mechanism features the quadrupedal launch model that I proposed in 2008, and which was further used to make predictions about pterosaur ecology by Mark and I in the PLoS ONE paper. Julia Molnar generated a wonderful animation of quadrupedal launch for Anhanguera, and it has appeared across multiple venues, including National Geographic. She was subsequently kind enough to make it freely available on YouTube. I have inserted the video below. You can also pull it up by clicking here.

I have written about quadrupedal launch on other web resources previously, so I won't belabor the point here. In short, takeoff acceleration in animals tends to be generated mostly by the walking limbs, rather than the wings. As such, takeoff is really a form of running or leaping (usually the latter). The strengths of the limb bones in bending and torsion, particularly with regards to the moments sustained for leaping, are therefore highly indicative of launch mode. Pterosaurs turn out to be much more bat-like in this regard than bird-like: they had forelimbs which were much stronger than the hind limbs across a wide range of body sizes. By contrast, large birds have stronger hind limb elements (particularly the femur) when compared with the forelimb elements. Giant pterosaurs, such as Quetzalcoatlus, had very long, thin hind limb elements, which argues against a bird-like launch. However, because pterosaurs walked on their folded wings, as well, the incredibly robust forelimb musculature and structure could provide most of the launch power (and sustain the resulting forces) during a quadrupedal launch. Since pterosaurs were quadrupedal while moving on the ground to begin with, this is actually the most simple model, as well. Modern bats, particularly vampire bats and New Zealand short-tailed bats, use a quadrupedal launch.

There are a host of other problems with a bipedal launch in pterosaurs, including problems with angle of attack of the wing, trailing edge flutter, Wagner effects, insufficient height and time, and pitching instabilities. Depending on interest, I may do a summary of these observations at a later date.

There is not much to say specifically about the flight patterns. One nice thing was that the flapping amplitudes used were pretty reasonable. The wing cycles are probably a bit too large in some cases (particularly the Quetzalcoatlus models that do flybys), but it's usually much worse. The problem here is that large animals actually tend to fly with more shallow wing strokes, especially if they have high aspect ratio wings. This tends to make a distant albatross etc. seem a bit smaller to us than it really is, and the same happens when doing pterosaur models - they just don't look as huge if you model them correctly. In Clash of the Dinosaurs, I tried very hard to get the animators to reduce the flapping amplitude of the Quetzalcoatlus model to no avail - there was a general feeling from those working on the show that the giant size didn't come across with the lower-amplitude wingbeats that are predicted by anatomy and fluid mechanics. Oh well, such is life.

Friday, July 22, 2011


On the note of shameless plugs, readers of pterosaur.net may be interested to know that Justin Hall and I have launched a paleo blog called H2VP that will focus primarily on functional morphology and biomechanics of fossil vertebrates. We will be discussing pterosaurs from time-to-time (though I will be posting the dedicated pterosaur work here), as well as other Mesozoic animals that pterosaur enthusiasts may have interest in (right now theropods are featuring strongly, and an article on Mosasaurs will be forthcoming soon).

The blog can be found at: http://h2vp.blogspot.com/

Wednesday, July 6, 2011

Crazyass pterosaurs and massive, shameless self-promotion

It's been a good while since I've posted anything here at Pterosaur.Net, and with good reason: a fair number of little projects, writing a book, moving house and the continued search for employment have kept me pretty busy for the last few months. One little project that I thought would be of interest to Pterosaur.Net readers, however, is my own website, the ego-trip/interactive CV/desperate bid for work that is Markwitton.com.

I've never designed a website before, resulting in a pretty simple design but, happily, I reckon it's fairly easy to read and navigate. I'll wager that Pterosaur.Net readers will find the full details of my upcoming Princeton University Press book, simply called (for the time being, anyway), Pterosaurs of most interest: you can find a full contents listing, sample imagery and an entire sample chapter, that dedicated to the recently-discovered weirdo pterosaurs from China, the boreopterids. Long term denizens of this blog may remember that Dave Hone mentioned Zhenyuanopterus, a recently discovered boreopterid, on these pages in March of 2010, and you can see a couple of the same critters lazily decorating the top of this post. They're crazy looking animals, bearing tiny, piggy-little eyes and buttloads of needle-like teeth that look useless for anything but straining pasta. But what sort of pterosaurs are they? How many boreopterids are there? Where and how did they live? Point your browser here to find out. (Snazzy Markwitton.com logo shown below)

Other pages of note include new illustrations, technical drawings and details of the 2010 London Royal Society/University of Portsmouth pterosaur exhibition and other sculptures. Oh, and a full list of my technical publications, including links and downloadable pdfs, can be found here. Please take a look and, by all means, drop me a line if you have any comments (especially if you have any functionality issues: I'm sure there's some kinks to work out. The same goes for typos I may have missed, for that matter).

No promises to post anything here anytime soon, I'm afraid: I'm moving house in the coming weeks and am quite desperate to get this book of mine finished, so I simply won't have the time. I genuinely don't know how regular bloggers manage to keep up their output: they must never sleep. Or eat. Or get distracted for long periods in the shower by their toes. In any case, I hope to get back to regular posting at some point in the future, but can't quite say when. Until then, thanks in advance for taking a peep at my site, and I hope you enjoy what you find.

Thursday, June 16, 2011

Interview with John Sibbick

Over on my main blog I have an interview with palaeoartist John Sibbick. This is rather relevant to P.net as John was the artist for the very important pterosaur encyclopedia of Peter Wellnhofer back in 1991. John was good enough to share a bunch of his artwork, including some of his originals for this book and a rather nice Dimorphodon skeleton. So click on the link and go and enjoy.

Saturday, May 14, 2011

A Pterosaur Revolution?

Back on my Archosaur Musings, I've been talking about dinosaur discovery rates for the last day or two and it seemed worth musing for a few lines on the same phenomenon with regards to pterosaurs. New pterosaurs are being discovered at only about a quarter of the rate of new dinosaurs, though given that there are far fewer pterosaur researchers than there are for dinosaurs, and the overall greater rarity of pterosaurs, this in fact probably represents an overall relatively higher rate of pterosaur discovery even if the absolute numbers are lower. That is already quite significant to my pterosaur-centric mind and belies the pterosaur revolution we seem to be undergoing.

On a slightly cloudier note, the ongoing controversy and problematic taxonomy of a number of groups or genera does mean that it's likely that a number of these new taxa will be sunk back into obscurity. While obviously this is the fate of some taxa in all groups, to my eye the pterosaurs to tend to do a bit worse in this area that do say the dinosaurs. Still, when just a few years ago Dave Unwin surmised there were only around 110 valid pterosaur genera after nearly 200 years of research, the fact that we have been able to add around 20 more in the last three years alone is stunning. Next year might well provide a bumper harvest too with the next Flugsaurier volume due.

While they're never going to get the same attention as dinosaurs, the last decade for pterosaur research really does point to a quiet revolution. We have more active researchers now than ever before (and by a fair margin) and we seem to be drawing in more attention from other workers (that is, there are quite a few dinosaur and archosaur guys who dabble with pterosaurs when in the past they wouldn't have done so) and we're getting together regularly too and producing whole volumes of papers. We're seeing not just a huge increase in the numbers of new genera, but even entire new clades like the boreopterids and chaoyangopterids, unexpected late surviving toothed taxa, and of course Darwinopterus makes quite a difference. There are also major increases in our knowledge of older taxa - there are lots more anuroganthids and azhdarchids than a few years back, and other discoveries are adding massively to our knowledge. You'd struggle to find even a handful of really good specimens with soft tissues a decade ago but now we are positively blessed, and we now have 4 pterosaur eggs (and three of them with embryos) when before 2004 we had none.

At the risk of a little hyperbole, I really think we are in the midst of something special happening with pterosaurs and I genuinely think that in a few decades we will look back at the time between around 2000 and 2020 as the time when we really got to grips with these taxa and much of our knowledge settled into a familiar pattern. There will of course be more surprises and changes to our ideas, but this is very probably the beginning of a new age of pterosaur science and their renaissance (which dinosaurs had in the 80s and 90s) is begun.

Monday, April 11, 2011

Functional Morphology of Anurognathid Pterosaurs

I recently gave a talk with my preliminary results regarding anurognathid biomechanics at the GSA Northeastern Division Conference. There's nothing particularly shocking in it, but I have decided to post some of the highlights from my abstract and presentation here since this information is now technically "public". Obviously I am sitting on more data and results than appears here, which will be in a forthcoming manuscript.

On to the frog-mouths...

Anurognathid fossils include several exceptionally well-preserved specimens, some of which include extensive soft tissue preservation. This exceptional amount of morphological information makes anurognathids prime candidates for functional biomechanical analysis. Furthermore, anurognathids displayed a suite of unusual characteristics that make them of particular interest for functional study. These traits included extensive pycnofiber coverings, fringed wing margins, shortened distal wings, shortened faces, and enlarged orbits. Prior authors have suggested that anurognathids were adapted to catching small insects on the wing. My quantitative analysis that supports this general behavioral inference, and provides details regarding probable anurognathid locomotion.

First off, bone strength analysis in Anurognathus ammoni reveals that each proximal wing was capable of supporting nearly 22 body weights of force. The wing spar of A. ammoni was substantially stronger in bending than that of an average bird of the same size, and the calculated relative bone strength from Anurognathus ammoni overlaps significantly with that of living birds that capture prey on the wing (p>0.92) but differs significantly from all other avian morphogroups (p<0.04).

This might might seem like an obvious result, given all of the traits of the anurognathid skeleton already associated with insect capture, but it is important to remember that "insect capture" is an incredibly wide spectrum of feeding ecologies. There are, after all, quite a number of insects out there (as in, more than any other animal group) and so there are a diverse array of insect predators, as well. Only a subset of insectivorous vertebrates capture prey with a rapid pursuit on the wing - many bats, for example, are gleaners that pull insects from substrates. Some insectivorous bats and birds hawk insects only over short distances, or feed mostly on slow-flying prey. That Anurognathus ammoni seems mechanically similar to animals like fast-flying bats, kestrels, and swallows may not be all that shocking, but it's still useful information.

Anurognathid launch appears to have been particularly rapid and steep (more on this another time), and once airborne, anurognathid pterosaurs could likely generate high lift coefficients. Leading edge structure reconstructed from the soft tissue of Jeholopterus suggests that anurognathids were capable of generating a leading edge vortex (LEV) as observed in some living bats and birds (particularly swifts and flycatchers). I cannot calculate exactly how strong the LEV was - there simply is not enough detail in the soft tissue to tell - but in living vertebrate flyers a sustained LEV can pump up the lift generation by about 40%.

Analysis of flapping efficiency suggests that the expansion of the proximal wing, coupled with reduction of the distal wing elements, would have increased flapping power at the cost of slightly increased drag. The proportions of the wing and details of the shoulder may be indicative of the ability to hover for brief intervals (again, I shall be cruel and make everyone wait for details on this one). Overall, these results are consistent with reconstructions of anurognathids as highly maneuverable flyers, preferentially foraging on small aerial prey, likely at high speeds and accelerations. Conclusions regarding the effects of the extensive insulation on boundary layer control and such are pending analysis.

Wednesday, March 30, 2011

Pterosaurs...sort of

A couple of weeks ago the scientific podcast that is Science...sort of ran a piece on this pterosaur paper of mine. Unfortunately, despite their normal sterling efforts, this wasn't really an accurate representation of pterosaurs or our research. Happily though, they were receptive to me pointing this out and were kind enough to immediately invite me and Ross Elgin onto the show to talk pterosaurs. That podcast is now up and you can drop in at this link here to hear us pontificate about those lovely flying reptiles and our work on them and of course giving Pterosaur.net a bit of promotion.

Sunday, March 6, 2011

Catching up

While we do try on Pterosaur.net to bring you the best of new pterosaur research, the fact that most of us blog independently of this site and have various other commitments means we aren't always quite as prompt as we should be, even for big stories. Thus while between us we did cover the amazing new specimen of a Darwinopterus preserved in association with an egg in several ways, we never actually wrote about it on here.

This specimen was described by longtime P.net friend Lu Jungchang (pictured above in front of his poster of a putative male and female Darwinopterus by our own Mark Witton) who also organised the 2010 pterosaur meeting in Beijing. 'JC' has been kind enough to let us use various photos of his specimens in the past and in this case let me have some extra photos for my post on this topic over at the Archosaur Musings. Meantime, Darren Naish has been blogging on the implications for pterosaur dimoprhism and behaviour over on Tetrapod Zoology so check them out for more details.

If you do want something a bit more recent though, I'm back at the IVPP in Beijing temporarily and lots of pterosaur specimens are currently on display. That lets me start up a special 'Pterosaur Week' so keep coming back on my site for the next few days and you can begin your tour with Haopterus.

Tuesday, February 22, 2011

Too Big to Fly? Giant pterosaurs take wing in PLoS ONE

My post today is in the spirit of the old phrase "better late than never". As some of you may have already noted, Mark Witton and I produced a manuscript on giant pterosaurs back in November of 2010. David Hone was kind enough to link to the manuscript (which is freely available online in PLoS ONE) a while back, but I thought I'd shock everyone and actually discuss the manuscript a bit.

The basic idea of the manuscript was actually pretty straightforward - there have been a few papers published since 2004 that have suggested flightlessness for giant pterosaurs and/or suggested that they would be flightless at the body masses currently estimated for them. Mark and I were immediately skeptical of a number of the assumptions in these papers, and furthermore, we felt that it was about time that someone actually put forth a publication that made a quantitative argument for the ability of giant pterosaurs to fly. There has been a general consensus on that fact from the research community for a long time, but strangely enough, no one had previously sat down and actually laid out all the reasoning in a peer reviewed publication.

The arguments we make in the paper come in basically two types: 1) We demonstrated that pterosaurs cannot be simply modeled as birds and 2) the anatomy of pterosaurs independently suggests the ability to fly.

The first of these arguments was critical because prior assessments of pterosaur flight dynamics have often been derived from simple scaling of bird models. More to the point, all of the papers suggesting that giant pterosaurs were flightless did so through analogies with living birds. There were three such papers of interest. The first was Chatterjee and Templin (2004) that indicated a mass limited for a launching Quetzalcoatlus of 75 kg. Given the current mass estimates of 250 kg, that was quite a conundrum. However, as it turns out, Chatterjee and Templin assumed a bird-like launch strategy. More recent work by myself, Mark, and Jim Cunningham strongly indicates that this assumption is weak, and that pterosaurs were most likely quadrupedal launchers. Changing the launch model blows the lid off the 75 kg mass limit (and for those of you that are curious, 250 kg isn't the limit, either. More on that some other time, but in short, pterosaurs could have achieved larger sizes than Quetzalcoatlus).

The 'pterosaurs are not birds' problem also breaks down the argument of the second manuscript in question, Sato et al. (2009), which used accelerometer data from tube-nosed seabirds during takeoff and cruising flight as a benchmark for analyzing pterosaurs. The avian data in that manuscript are excellent, but alas they cannot be extrapolated to pterosaurs. The most recent manuscript to suggest flightlessness in pterosaurs is Henderson (2010), which applied an excellent new method of mass estimation to some sadly outdated models of pterosaur body shapes. The resulting estimate for body mass in Quetzalcoatlus was more than double that of even the highest previous estimates, but this estimate drops back close to that of Witton (2008) if an updated body volume is used. It is also worth noting here that we found no evidence for major size differences between the handful of giant azhdarchid pterosaurs - taking into account distortion, the Hatzegopteryx humerus is the same size as the Quetzalcoatlus humerus, more or less. As such, the largest known pterosaurs from multiple locations probably all come in around 10.5 meter wingspan mark.

So that's the bird analogy issue in a nutshell. But what about direct evidence of flight ability from the anatomy of the critters themselves? Mark and I examined the forelimb skeleton of giant pterosaurs, and showed (with both quantitative analysis and comparative anatomy) that the forelimb of big pterosaurs was considerably more robust than would be expected for simple quadrupedal walking. Furthermore, if one uses the most recent estimates of wing shape and body mass for the giants, the estimated climb out range and soaring distance available are both really quite impressive. So then, even if we assume that the largest pterosaurs could only flap for a short burst (which is likely), they would have had a couple of kilometers of range before they had to switch to soaring flight (thermals, etc) which shoots another hole in the "too big to fly" argument.

Add into all that our analysis of terrestrial competence in these animals (which was decent for some giants, like azhdarchids, but pretty limited for Pteranodon and kin), and some general issues about estimating body mass and you have our PLoS ONE paper in a nutshell. Good times. For those of you still searching in earnest for the original paper, you can turn your browsers here.

Saturday, January 29, 2011

The one-word review of Flying Monsters 3D

Falling over yourself to read Pterosaur.Net's review of the new David Attenborough documentary Flying Monster's 3D but just don't have the time to absorb all 3,184 words of it? No sweat: Pterosaur.Net regular Mike Traynor sent me this image that sums it up for us in a single word comprised of three simple letters (not sure how you have complex letters, actually, but never mind).

Thanks to Mike for allowing use of his image, and steer your Interweb craft here to read the slightly longer version.

Tuesday, January 25, 2011

What despair, pterosaurs and David Attenborough have in common

We all have our own little guilty pleasures amongst our DVD collections, films that we watch when we’re glum or tired and very, very much on our own. You don’t want to watch these things with your buddies, see, because they’re massively embarrassing for one reason or other. They may have really crappy plots or autopilot scripting, or perhaps more emotional mush than the output of a flood at an instant mash potato factory. The acting may be so wooden that, with only a little sawing and polishing, you could easily fashion it into a neat bedside table and, in effects-laden films, we may find The Muppets or Button Moon more convincing depictions of reality than the cheese being touted onscreen. Sensible souls keep these discs in the same place as their prophylactics and haemorrhoid creams, the sort of nooks and crannies that friends and casual visitors won’t happen to chance across when visiting, and daren’t defend them when they’re rightly ridiculed in conversation. We keep our thoughts on them private, see, and daren’t tell anyone how we spend our guiltiest filmic moments. Well, mostly: my personal guilty pleasure is the 1992 Tim Burton movie Batman Returns, a flick I fondly remember watching over-and-over as an kid for its dark, twisted visuals, fantastical plot and (for an eight year old) complex characters: how could the good guy fall in love with a baddie, after all? The shots of Michelle Pfeiffer wielding a whip in a PVC catsuit, sparking all sorts of previously unknown and confusing thoughts in my eight year old brain, had nothing to do with my repeat watching at all. And they certainly don’t factor into any decision I may make into watching it now.

Thing is, I know when putting the disc into my DVD player that I need to switch my brain off to enjoy it. I’m not watching it to be intellectually stimulated: it’s pure bumph and mental comfort food. Thinking about the silliness of it all too much will just ruin it, so best to sit back and let it wash over you like the celluloid bubblebath that it is. For other films or programmes, though, you don’t expect to do this, and particularly so for documentaries. Their whole purpose, after all, is to present factually informed opinions and data: they exist to educate and stimulate us with new information. What then, should we make of a documentary that has less in common with an educational experience and more of a guilty pleasure, the sort of thing that hardcore documentary-aficionados will scorn and only the bravest admit to truly liking? The kind of documentary that asks you to kindly switch your brain off before you’ll be able to enjoy it?

You can see where this is going
Call a spotlight, please, on the new Atlantic Productions/David Attenborough pterosaur documentary, Flying Monsters 3D (cropped promotional poster and trailer shown above. All images used in this post are (c) Atlantic Productions). Hyped across the UK through a pretty extensive media campaign featuring articles in newspapers, TV guides, the Internet, television and even adverts on the London Underground, it’s a flagship show for Sky TV’s (the major subscription satellite TV company in the UK) new 3D channel, an attempt to show people that they should fork out for a 3D TV and Sky subscription even if they’re not interested in the major component of Sky 3D’s output, football. Much of the excitement about the programme has focused on its use of 3D technology, but there’s good reason to be excited about its content, too. The programme’s lead, Sir David Attenborough (shown below in a glider alongside the FM3D Quetzalcoatlus), needs no introduction to anyone reading this and the producers, Atlantic Productions, are veteran CG palaeodocumentary makers that have cut their palaeodoc teeth on the pliosaur-based Predator X, the Darwinius feature Uncovering Our Earliest Ancestor: The Link and Attenborough’s recent tour through the origins on life, First Life. And it exclusively features pterosaurs for chrissakes, fantastic animals that have been begging for their own CG-laden documentary since Walking with Dinosaurs demonstrated that photo-realistic CG creatures were not just the claim of Hollywood blockbusters. A handful of pterosaur researchers were consulted in the making of the film, too – David Unwin, David Martill, Michael Habib and myself were all involved to ensure the science was on the money. With credentials like that, it’s understandable that expectations were higher for this than for many palaeodocs and, indeed, the programme has caused a stir around the world with palaeobloggers-a-plenty eager for it to land on their cinematic shores this Spring. The press reports have been positive too, with Attenborough and the technology of the film being highly praised in several articles.

Not having any of the necessary kit to see the show, I didn’t see the programme’s premiere at Christmas but, happily for me, my involvement as a technical consultant landed me and my other-half the chance to see a screening of the full length 70-minute version last Thursday (the upcoming cinema release is only 40 minutes). With such a stir around the film already, my hopes were high that everyone’s favourite leathery-winged beasties were about to get their moment in the media sun. Problem is, while some people are going to love this film - they're going to lap up the effects, the bizarreness of pterosaurs and the whispered Attenboroughness of it all, they won't be the people who're most excited about seeing it. No, I reckon that anyone with a real interest in palaeontology or pterosaurs, the sort of people who tune into this little corner of Hardcore Pterosaur Blogging, for instance, will be pretty underwhelmed with the whole thing. Indeed, it's not going to blow away anyone who, you know, actually pays attention to the film. And here’s why.

You look so fine
First up, credit given where it’s due: much has been made of the technology fuelling the 3D-enhanced presentation of Flying Monsters 3D, and for good reason: the presentation is stunning (FM3D Tupandactylus above). Most scrutiny will undoubtedly focus on the computer generated pterosaurs and – regardless of their scientific merit (we’ll get to that later) – they look dead impressive. Their fuzz and wing membranes ripple in the wind, their animation is smooth and their (entirely CG) environments look rich and convincing. As with most films of this kind, the lack of other animals in the CG scenes is notable, but given the time and expense it would take to render such effects, this is forgivable. The traditional photography is nicely done, too, with plenty of dramatic shots of fossil sites from helicopters, some fantastic close-ups of well-known pterosaur specimens and a suitably stirring, Thomas Newman-esque soundtrack overlying the whole thing to get the attention of your neck hair. The 3D, perhaps the most hyped component of the whole film, works well and, happily, isn’t gimmicky: there’s no cheesy 3D money shots to make audiences lurch about their seats and, instead, it only serves to add depth of vision to the pictures. Personally, I’m not sure the 3D really made the film a whole new visual experience: while impressive for the first five minutes, it quickly becomes par for the course, aside from the need to continuously push oversize 3D specs up your nose. Still, it all adds to the excellent presentation served up by Atlantic, and their cinematographers and computer wizards deserve several pats on the back for their work. Problem is, once you’ve taken in how nice everything looks, you start to focus on the story you’re being told and the content of the programme, and that's where the issues begin.

As a documentary being presented by one of the most respected television natural historians of recent times, the content of FM3D has to match up to it’s presentation for it to be considered a real success. Alas, Flying Monsters 3D is a bit of a letdown here: I need to be careful with my own impressions here as, being a chap who’s been called a ‘pterosaur expert’ more than once, I may be more critical of the programme’s content than most. Thing is, this background means that I spent a lot of the film noting gross inaccuracies and misrepresentations of pterosaur knowledge, and this is surely a major failing of anything programme pretending to be a fact-based documentary. Take, for instance, the way that we’re explicitly told that pterosaurs were out-competed by birds and their ability to adapt to new ecologies, thus sealing the extinction of the more evolutionary-stagnant pterosaurs. Detailed analyses of bird and pterosaur diversity have either proved inconclusive on this issue (as in, we don't have enough data to say either way) or categorically stated that there's no evidence for bird-driven pterosaur extinction (Buffetaut et al. 1996; Slack et al. 2006; Butler et al. 2009; Dyke et al. 2009): claims like this really don’t reflect consensus opinions in the pterosaur scientific community. Elsewhere in the programme, we’re told that aktinofibrils – the stiffening fibres of pterosaur wings – enabled them to mould their wings in a very refined, precise way. These have been confused here with the muscle layer thought to be running through pterosaur wing membranes (Unwin 2005): aktinofibrils likely stiffened the wing or served as folding aids (Padian and Rayner 1983; Bennett 2000). Roborhamphus, the digital walking non-pterodactyloid pterosaur, is presented as strict fact despite still not being peer reviewed (and contradicting other evidence – see Bennett 1996) and the large tapejarid Tupandactylus is consistently called Tapejara despite being separated from this genus four (yes, four) sodding years ago (Kellner and Campos 2007). I mean, if you can't even be bothered to give them the right names...

Many sequences of the programme also shake the wrong end of the pterosaur stick, giving a rather inaccurate portrayal of pterosaur research and its history. A good chunk of the programme is given to the discovery of the Dimorphodon holotype, a partial skeleton found in 1828 in Dorset, as if it were pivotal in revealing pterosaurs to the world and understanding pterosaur morphology. This just isn’t the case: the first pterosaur fossil known to science, the complete skeleton of Pterodactylus antiquus, was found in 1784 and was a far more important specimen to our initial appreciation of pterosaurs. Not only did this fossil give pioneering scientists like Georges Cuvier the ability to interpret pterosaurs as extinct flying reptiles, but it was also a cornerstone for demonstrating concepts such as life before man, the use of comparative anatomy in identifying fossil animals and even extinction itself (Taquet and Padian 2004). While Dimorphodon was an important contribution to our knowledge of pterosaurs in 1828, it really did little more than demonstrate the temporal, geographic and morphological range of pterosaurs: it had nothing to do with discovering what pterosaurs actually were (and, besides, we didn’t see what Dimorphodon really looked like until the latter half of the 1800s, almost 100 years since pterosaur research began [Owen 1870]). Indeed, the programme’s emphasis on Dimorphodon as a completely known early pterosaur isn’t entirely clear: other forms (e.g. Preondactylus, Peteinosaurus and numerous campylognathoidid-like things) are as completely known and much older. (FM3D Quetzalcoatlus shown above)

It gets worse. For some reason, considerable screen time is given to the idea that Tupandactylus (sorry, ‘Tapejara’) had an ultra-sensitive headcrest capable of ‘autopiloting’ it’s flight. What’s more, we’re told that with backswept-wings, the same ornament would enable Tupandactylus to sail through water like a reptilian trimaran (as in, with it’s belly and legs acting as a hull and the wings and crest posing as sails). These ideas come courtesy of biomechanicist Sankar Chatterjee, who’s work builds upon minor statements about the sailing potential of other tapejarids made by Dino Frey and colleagues in 2003 (note that other discussions of sailing pterosaurs primarily focus on the antler-crested form Nyctosaurus: we don’t have time to go into them here). The science behind these claims has yet to reach the peer-reviewed press, however, and the idea of pterosaurs sailing in this manner has not gained any acceptance in mainstream pterosaur circles: with all due respect to Professor Chatterjee, I’m surprised the programme makers gave so much screentime to an idea that has such a long way to go before being accepted by the pterosaur community when there are other, equally interesting and far less controversial ideas they could have explored. They could’ve, for instance, demonstrated far more concrete ideas about crest dimorphism: virtually every animal in the film has a headcrest, giving the impression to pterosaur-savy individuals that the pterosaur social scene was something of a sausage fest. One sequence in particular stands out as the pterosaur equivalent of Brokeback Mountain.

These problems – and I’ve only listed a few - are bad enough, but the most surprising letdown of all is that the show lacks good narrative, a shock considering the involvement of the Godfather of natural history films. We’re taken through a simplistic version of pterosaur evolution, looking at Dimorphodon, Darwinopterus, Pteranodon, Tupandactylus (sorry, ‘Tapejara’), and Quetzalcoatlus, a sequence that takes us from the early Jurassic to the late Cretaceous. Along the way we’re introduced to some different species and concepts of pterosaur locomotion and anatomy and, in theory, this should work fine. In actuality, though, it’s rather clumsily handled. We’re told at the film’s midpoint that Tupandactylus had fur (a claim based on fossils, apparently, but the only Tupandactylus I know of with an alleged ‘beard’ has not been studied nor even mentioned in the technical literature. Having seen photos, I’m not sure that the alleged beard isn’t actually an errant plant fossil) and that this suggests it’s able to control it’s body temperature. It’s pretty accepted that most – if not all – pterosaurs were covered in fuzzy pycnofibres, and it’s not at all unreasonable to assume this may have been important to their ability to fly: why is this specifically mentioned for Tupandactylus but no other pterosaurs, then? (Scavenging FM3D Quetzalcoatlus shown above. Note that scavenging habits for these animals has never really gained much acceptance amongst pterosaurologists - see Witton and Naish [2008])

Often, the narrative feels entirely ad-libbed. The discussion of the concept that pterodactyloids represented a significant upgrade in terrestrial capability from their ancestors brings in the discussion of the split uropatagia in pterodactyloids when, prior to this point, viewers had not been introduced to the idea that there was any sort of hindlimb-anchored membrane at all (well, unless they’d been paying close attention to the CG sequences). Later, Douglas Lawson talks us through estimates of how large Quetzalcoatlus northropi was thought to be in the 1970s (about 17 m across the wings – see Greenewalt 1975) but the producers keep any subsequent size estimates (more like 10 m - see Witton and Habib 2010) to themselves: the point is set up, but never finished. There’s a massive contradiction, too, the bristle-toothed ctenochasmatoid Pterodaustro is identified halfway through the film as a filter feeder, only for Attenborough to close the film in front of a flamingo flock and inform us that pterosaurs never achieved the diversity modern birds have, including never evolving filter feeding forms. All told, it seems like this was a story told on the fly with little continuity checking between scenes. Indeed, we left the theatre wondering if anyone with access to the script, let alone someone with a background in pterosaur research, had read the narrative from beginning to end or really had a good, solid grasp of what they were trying to say.

All down to the 1s and 0s
It’s left to the CG pterosaurs to justify your subscription to Sky 3D or IMAX theatre ticket, then, but they’re not quite strong enough to support the whole thing alone. They are lovingly rendered and, anatomically speaking, not too bad (though there were a whole load of suggestions made that were rejected for aesthetic or economic reasons - FM3D Dimorphodon, shown above, has suffered a lot in this regard), but their flight animations – the main way we see them - are too sinuous and, like most prehistoric beasties on film, they scream and wave their heads around far too much. Overall, the Tupandactylus and Darwinopterus probably come out best, though some scenes, such as the sailing tapejarids, hawking Darwinopterus and crashing Dimorphodon aren’t convincing at all. Two of these instances are actually laughably bad (apologies to the animators, but the Dimorphodon sequence is begging for a WWII plane crashing sound effect to be added over the top: seriously, animals just don’t spiral out of the sky like that!). As such, I’m not sure they’ll come across as convincing to anyone who’s familiar with actual animal movement and behaviour, and folks who know pterosaur anatomy will wince at the flexibility of their backs and tails, the floppy-curtain effects of the wing membranes on the grounded animals and the stiff, perpetually-forward facing heads. They have got a lot right: their feet are plantigrade, they launch quadrupedally and their limbs held are positioned parasagittally, but their movements are too exaggerated. CG animators will do well to learn that animals don't move like they’re acting in silent movies. Plus, Attenborough actually interacts with the CG models in some scenes and, call me boring, but these come across as pretty trite and nuke FM3D’s fridge: the models aren’t really convincing enough to stand up to their real-world surroundings, and they come worrying close to turning Attenborough from respected educator into a children’s performer (see image, below, of the FM3D Quetzalcoatlus soaring alongside Attenborough's glider).

So... you didn't like it then?
Not really. As a pterosaur documentary it's probably the best one yet - though that's hardly a mean feat - but it's a pretty sub-par programme in it's own right. Thing is, I wouldn’t normally care: most palaeodocs are, unfortunately, pretty terrible at the best of times, but this one could’ve been so much more. Why so many silly mistakes? Why such chaotic narrative? Pterosaurs are awesome animals: the fact that they formed the focus of such a prestigious documentary shows their public appeal and the numerous articles, webpages and books written about them denotes their hardcore interest. Alas, the media hype for the film betrays the real interest of the filmmakers: the technology behind the film. Indeed, search the websites associated with the flick and you’ll not find any mention of the science behind the piece: there’s some basic facts about pterosaurs, but the vast majority of the hype concerns the involvement of David Attenborough and the details of making a film in 3D. As mentioned above, this will be enough for some who're bowled over by the snazzy visuals and polish, but anyone who doesn’t knock their brains to ‘off’ when slipping the 3D glasses on will find it disappointingly empty. It really seems that, with a bit more care, this could’ve been as much of an achievement for effective scientific communication as it has been for 3D technology, but it’s really an enormous missed opportunity. The kind of thing, in fact, that makes a technical consultant want to grab a beer or two and reach for that guilty pleasure DVD. Despair, despair, despair.


  • Bennett, S. C. 2000. Pterosaur flight: the role of actinofibrils in wing function. Historical Biology, 14, 255-284.
  • 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.
  • Dyke, G. J., McGowan, A. J., Nudds, R. L. and Smith, D. 2009. The shape of pterosaur evolution: evidence from the fossil record. Journal of Evolutionary Biology, 22, 890-898.
  • Frey, E., Martill, D. M., and Buchy, C. C. 2003. A new species of tapejarid pterosaur with soft tissue head crest. In: Buffetaut, E. and Mazin, J. M. (eds.) Evolution and Palaeobiology of Pterosaurs, Geological Society Special Publication, 217, 65-72.
  • Kellner, A. W. A. and Campos, D. A. 2007. Short note on the ingroup relationships of the Tapejaridae (Pterosauria, Pterodactyloidea). Boletim do Museu Nacional, Nova Séroe, Rio de Janeiro - Brasil. Geologia, 75, 1-14.
  • Greenewalt, C. H. 1975. Could pterosaurs fly? Science, 188, 676.
  • Owen, R. 1870. A monograph of the fossil Reptilia of the Liassic Formations Part Third. Plesiosaurus, Dimorphodon, and Ichthyosaurus. Palaeontographical Society Monograph, 41–81.
  • Padian, K. and Rayner, J. M. V. 1993. The wings of pterosaurs. American Journal of Science, 293, 91-166.
  • Slack, K. E., Jones, C. M., Ando, T., Harrison, G. L. (A)., Fordyce, R. E., Arnason, U. and Penny, D. Early penguin fossils, plus mitochondrial genomes, calibrate avian evolution. Molecular Biology and Evolution, 23, 1144-1155.
  • Taquet, P. and Padian, K. 2004. The earliest known restoration of a pterosaur and the philosophical origins of Cuvier’s Ossemens Fossiles. Comptes Rendus.Palaevol, 3, 157-175.
  • Unwin, D. M. 2005. The Pterosaurs from Deep Time. Pi Press, New York, 347 pp.
  • 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.

Friday, January 14, 2011

Pterosaur.net 2010 research roundup

One of the main motivations of the creation of Pterosaur.net was to get real information the public from real researchers. There is a ton of internet stuff on pterosaurs and (from what I have seen at least) the vast majority is out of date, badly put together, inaccurate or just amazingly wrong. Of course, the flipside of this is that we kinda need to show that we know what we are talking about. While that is actually rather hard to do, we can at least show that we are actively involved in research. Here then is a list of the papers and conference abstracts that the P.net team have been involved in over the last year. Given that for many of us, pterosaurs are not our main arm of research (Darren and I both do more dinosaurs than pterosaurs, Mike also works on birds), and that we do have other things to do as well (Ross has a PhD thesis to write, Lorna is a museum curator) it’s really pretty good.

In addition to most of us making it to Flugsaurier this year (which of course does bump up the abstract quotient) we have pushed out a decent sized fistful of pterosaur papers. While we don’t form any kind of formal research aggregate, the fact that we have and continue to collaborate within this community must make us one of, if not the, most productive and influential pterosaur group out there.

Conway, J.A. 2010 Reconstructing a pterosaur, a case study. Acta Geoscientica Sinica. 31(S1):14

Dyke, G., Benton, M., Posmosanu, E., & Naish, D. 2010. Early Cretaceous (Berriasian) birds and pterosaurs from the Cornet bauxite mine, Romania. Palaeontology, DOI: 10.1111/j.1475-4983.2010.00997.x

Elgin, R.A., Hone, D.W.E. & Frey, E. The extent of the pterosaur flight membrane. Acta Palaeontologica Polonica, in press.

Habib M. 2010. The structural mechanics and evolution of aquaflying birds. Biological Journal of the Linnean Society. 99(4): 687-698

Habib, M. 2010. 10,100 Miles: Maximum range and soaring efficiency of azhdarchid pterosaurs. J. Vert. Paleontol., SVP Program and Abstracts Book, 2010: 99A. 2010. Soaring efficiency and long distance travel in giant pterosaurs. Acta Geoscientica Sinica. 31(S1):27-28

Habib, M, Cunningham J. 2010. Capacity for Water Launch in Anhanguera and Quetzalcoatlus. Acta Geoscientica Sinica. 31(S1):24-25

Habib M, Godfrey S. 2010. On the hypertrophied opisthotic processes in Dsungaripterus weii Young (Pterodactyloidea, Pterosauria). Acta Geoscientica Sinica 31(S1):26-26

Hone, D.W.E., Lü, J. 2010. A new specimen of Dendrorhynchoides (Pterosauria: Anurognathidae) with a long tail and the evolution of the pterosaurian tail. Acta Geoscientica Sinica. 31(S1):29-30

Hyder, E. S., Martill, D. M. and Witton, M. P. 2010. A neoazhdarchian pelvis with a possible preserved air sac from the Santana Formation of Brazil: implications for functionality and phylogeny. Acta Geoscientica Sinica, 31 (1), 32-32.

Monninger, S., Frey, E., Elgin, R., Tischlinger, H., Sartori, J., & Schneider, P. 2010. Folds, wrinkles and the material properties of the pterosaurian flight membrane. Acta Geoscientica Sinica. 31(S1): 52

Moody, R. T. J. & Naish, D. 2010. Alan Jack Charig (1927-1997): an overview of his academic accomplishments and role in the world of fossil reptile research. In Moody, R. T. J., Buffetaut, E., Naish, D. & Martill, D. M. (eds) Dinosaurs and Other Extinct Saurians: A Historical Perspective. Geological Society, London, Special Publications 343, 89-109.

Naish, D. 2010. Pneumaticity, the early years: Wealden Supergroup dinosaurs and the hypothesis of saurischian pneumaticity. In Moody, R. T. J., Buffetaut, E., Naish, D. &Martill, D. M. (eds) Dinosaurs and Other Extinct Saurians: A Historical Perspective. Geological Society, London, Special Publications 343, 229-236.

Nesbitt, S.J. & Hone, D.W.E. An external mandibular fenestra in pterosaurs supports placement within Archosauriformes. Palaeodiversity, 3: 225-233.

Steel, L. 2010. The Pterosaur collection at the Natural History Museum, London, UK, overview, recent curatorial developments and exciting new finds. Acta Geoscientica Sinica. 31(S1):59-61

Tomkins, J. L., LeBas, N. R., Witton, M. P., Martill, D. M. and Humphries, S. 2010. Positive allometry and the prehistory of sexual selection. The American Naturalist, 176, 141-148.

Tütken, T., Hone, D.W.E. 2010. The ecology of pterosaurs based on carbon and oxygen isotope analysis. Acta Geoscientica Sinica. 31(S1) 65-67.

Witton M, Habib M. 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. doi:10.1371/journal.pone.0013982

Witton M, Habib M. 2010. The volancy, or not, of giant pterosaurs. Acta Geoscientica Sinica. 31(S1):76-78

Witton, M. P. 2010. Pteranodon and beyond: the history of giant pterosaurs from 1870 onward. In: Moody, R. T. J., Buffetaut, E., Naish, D. and Martill, D. M. (eds) Dinosaurs and Other Extinct Saurians: A Historical Perspective. Geological Society, London, Special Publications, 310, 313-323.

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.

Tuesday, January 11, 2011

Gwawinapterus takes wing

Yep there's another new pterosaur on the block (and on the blog for that matter). Gwawinapterus is a new istiodactylid from Canada and the first from the Americas. I have a guest post from describer Victoria Arbour up on the Musings, so head here to take a peek.

Victoria M. Arbour; Philip J. Currie (2011). “An istiodactylid pterosaur from the Upper Cretaceous Nanaimo Group, Hornby Island, British Columbia, Canada.”. Canadian Journal of Earth Sciences.

Late edit: Victoria has also blogged about this on her site as well.