The blog can be found at: http://h2vp.blogspot.com/
Friday, July 22, 2011
H2VP
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).
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.
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.
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.
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