Big Pterosaurs Really Did Fly: Interview with Mark Witton Part II

A new paper in PLoS ONE, by Mark Witton and Mike Habib, re-evaluates claims that big pterosaurs were too big to fly. To make a long story short, multiple lines of evidence suggest that giants like Quetzalcoatlus really did take wing! One of my previous blog posts summarized the paper and featured the first part of an interview with senior author Mark Witton. That part of the interview focused on many of the scientific aspects of the research. Today, we'll highlight some of the other highlights. I think you'll find it illuminating!

This paper has received a fair bit of press coverage. Is there anything about the research that you wish had received more attention?
Our coverage was really good: as mentioned above, we ended up in the most unlikely of places along with getting pieces in much more familiar territory. In that respect, I can’t complain but, at the same time, the press really focused on the quadrupedal launch idea [illustrated at right, with a Pteranodon launching itself in this fashion; figure from Witton and Habib 2010] which, while still quite novel to most, was actually first proposed (in print) by Mike back in 2008. There was a fair amount of press coverage for the idea back then, too. Prior to that, though, both Mike [Habib] and Jim Cunningham, who developed the same idea independently of Mike, had given the idea considerable airing on the Dinosaur Mailing List. Bottom line: this latest paper really isn’t the first to comment on it in any capacity. We talked about it a lot, but we’re definitely not its origin. Still, the press really ran with it, despite the fact that the main thrust of our paper is that pterosaurs and birds are generally incomparable beyond very basic aspects of their flight mechanics, and that previous assumptions that they were had lead to probably incorrect assumptions about their way of life. Their disparate launch mechanisms are a particularly important part of our considerations, but they are only one part of many. It’s no big deal, really, but I’m a little concerned that some people will now associate quad launching with this paper and I really don’t want to steal the thunder away from Mike and Jim: they did the real work on it. I’m sure People in the Know will realise the score, but I’ve already had e-mails about the presentation of the quad launch in our new paper like we proposed it. Tell the world, folks: quadrupedal launch came from Mike and Jim! They’re the real geniuses here!

With you in the UK and Mike in the US, the paper is a very international collaboration. What sort of challenges, if any, were particular to this sort of cross-border work?
Mike and I met up twice during the work on the project at different conferences, but, that aside, we worked entirely through e-mail. Trite as it sounds, the internet is amazing: a project like this would be so much harder and longwinded without it. Throwing drafts of the MS at each other, bouncing ideas around and working on the figures was no sweat at all. We could have revisions done and sent back to each other as fast as we could turn them around. In that respect it was as efficient as working with someone in the same department, if not slightly more so, as meandering chats and tangential fieldwork anecdotes – always a risk of visiting the office of any academic – were largely kept out of our online conversations (we made up for it at conferences, though). The long duration spent putting the paper together, mentioned above, was mainly thanks to my workload with the pterosaur models, not anything to do with working internationally. The paper spent a long time sitting on my desk as my time for writing disappeared amidst a blur of fake fur, bluefoam and acrylic paints. So no, working internationally presented very few obstacles. I’m sure the story would be very different if we were working 20 years ago or so, but, today, you can work with whoever you want, wherever they are without a hitch. Well, assuming they check their in-box regularly, that is.

Thank you, Mark, for an informative interview!

Citation
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) DOI: 10.1371/journal.pone.0013982

[full disclosure: I am an editor at PLoS ONE, the journal in which this paper appeared]

Big Pterosaurs Really Did Fly: Interview with Mark Witton

Pterosaurs - winged denizens of the Mesozoic skies - get a bum rap. It's bad enough that their name is smeared by the general public, when animals like Pterodactylus are confused with dinosaurs in the news media and in just about every cheap set of plastic dinosaurs. Lately, some scientists have suggested that the largest of these animals just couldn't fly. Is it true that Quetzalcoatlus (pictured here; image from Wikimedia Commons), with its 10 meter wingspan, had wings that were too narrow, a body that was too portly, and bones that were too weak to support flight? Some of the most recent studies have certainly suggested this!

Yet, extraordinary claims require extraordinary evidence, or at least extraordinary scrutiny. Thus, a study by pterosaur experts Mark Witton and Mike Habib takes a close look at the idea of super-lame flightless giant pterosaurs. Using new body mass estimates, revised reconstructions of the wing dimensions, bone strength calculations, and many other lines of evidence, Mark and Mike argue that even the biggest Quetzalcoatlus could fly after all.

This paper, published in PLoS ONE [full disclosure: I am an editor for this journal], has been featured all over the mainstream news media and blogosphere. For a slightly different take on the matter, I decided to go straight to the source. Mark Witton (pictured below; thanks to Mark for the picture, copyright him) was kind enough to answer a few questions about the study - not just on its methods, results, and conclusions, but also on some of the behind-the-scenes doings that led up to this work.

I've split this interview into two parts. For starters, we'll talk about the genesis of the paper, and some of its major findings.

How did this study come about? Did any particular event spur you and Mike [Habib] into working on this issue of flight in giant pterosaurs?
I reckon a paper like ours has been a long time coming, really. There’s been a lot of talk in recent years that pterosaurs may not be what Greg Paul termed ‘ultralight airbeings’, and numerous blogs and internet forums have responded with comments what this may mean for their flight dynamics. It was only a matter of time before the flight of realistically massed pterosaurs was considered in the technical literature (well, beyond saying they couldn’t fly). We were kicked into action, though, when press reports of an abstract presented by Katsufumi Sato et al. were released in April 2009, saying giant pterosaurs couldn’t fly. Keen members of the palaeoblogsphere may remember this ruffled a fair few feathers when it was released, and their paper (Sato et al. 2009) followed shortly to similarly raised-eyebrows. Most folks even vaguely familiar with large pterosaurs were astonished to see them cap flight at such a low size: 41 kg and 5 m wingspans are very middling in the spectrum of pterosaur size (10.5 m spans and 250 kg body masses are considered maximum in our paper). Because plenty of clearly-flight adapted forms got much larger than this, I got to work on a response. Mike and I have fairly regular correspondence and were talking about the project soon after I started, and it wasn’t long before we realised that working together would make the project much stronger.

Plus, I had giant pterosaurs on the brain at that time. I’d just started work on a massive modelling project where I had to build several models of the largest pterosaurs going. The logistics and costs of building a 13 m span pterosaur against a 10 m span animal is quite something, so I figured a little checking of the wingspans of these poorly known animals wasn’t the worst way to spend an afternoon as it would avoid having to find a bigger workshop. The timing of this was spot on for the project with Mike, too, as it meant we could ensure the size estimates for our flight analysis were as accurate as we could make them. These two events combined to form the beginnings of the paper and reminds me that we started it well over a year ago: where did that time go?

What was the most surprising finding to you, and why?
The most surprising? Hard to put my finger on one thing exactly: we covered quite a lot of topics, and each had their own intriguing little revelations. I mean, the 13 m span estimates of Arambourgiania, the giant pterosaur from Jordan, always seemed a little iffy to me because they were based on a single neck vertebra, but not Hatzegopteryx. Being based on forearm material, I figured the 12 m span estimate for this critter was a sound bet but, no, the material just seems distorted to appear bigger than it actually is. The numbers generated in the flight analysis for the speed of flying giant pterosaurs were impressive, too. The thought of a giraffe-sized pterosaur pumping its wings to scream overhead at 75 mph is staggering: this is real ‘if I had a time machine…’ stuff.

That said, for all these little surprises, the biggest ones came from the paper’s release and press coverage: I was really blown away to see just how much interest we had. To be honest, we did want to make a splash because, following the Sato et al. abstract, the internet is awash with articles saying giant pterosaurs couldn’t fly. We wanted to balance it out a little (this is also, incidentally, why we chose PLoS ONE as our venue: we want interested people of all backgrounds to be able to see our rationale for flighted giants: open access is definitely the way forward, folks). However, I was truly taken aback when our work was quoted directly alongside some half-naked chick in the British tabloids newspaper, The Sun. How often do science stories penetrate that far into the press, let alone those dealing with relatively unimportant extinct flying reptiles? I can only assume that pterosaurs are becoming more exciting and cool with every new discovery, or it was a slow news day. Either way, I’ve not stopped telling people about that since.

Next Time. . .the ins and outs of trans-Atlantic collaborations, and what the media should have mentioned.

Citations
Sato, K., Sakamoto, K., Watanuki, Y., Takahashi, A., Katsumata, N., Bost, C., & Weimerskirch, H. 2009. Scaling of soaring seabirds and implications for flight abilities of giant pterosaurs. PLoS ONE, 4 (4), DOI: 10.1371/journal.pone.0005400.
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) DOI: 10.1371/journal.pone.0013982

For All You Pterosaur Fans

Dave Hone has asked me to pass on his announcement of the launch of pterosaur.net. This new web page is a collaborative effort by a number of pterosaur experts to provide a gateway to accurate, scientifically-based information on this fascinating clade. It looks great, both in terms of content and some eye-popping artwork, so I strongly recommend checking it out!

Albatross vs. Pterosaur

Today, there was a paper tangentially related to pterosaurs in the open access journal PLoS ONE. A team of investigators wired up albatrosses and petrels with accelerometers, in order to measure the percentage of time these animals spent flapping their wings and soaring. They found two main styles of wing flapping (as inferred from the accelerometer measurements): 1) high frequency flapping during take-off; and 2) low-frequency flapping during soaring. Interestingly, the frequencies scale with body mass in such a way that a maximum possible body size for the albatross-like body plan that still allows flight is extrapolated to a body mass of 41 kg and wingspan of 5.1 m (with the requisite error bars, of course).

The authors then go on to discuss the implications for pterosaur paleobiology, essentially suggesting that albatross-style soaring was physically impossible for pterosaurs such as Quetzlcoatlus (assuming that it also had albatross-style wings). Frustratingly, there is little discussion of the alternative possibilities of wing shape in pterosaurs, among other things. Furthermore, the underlying data for the analysis only focus on four species of birds with limited morphological diversity. As suggested by the authors of the current paper, data on thermal-soaring birds such as condors (which have a decidedly un-albatross-like form) are sorely needed.

So, kudos to Sato et al. for collecting some interesting morphological data. This sort of information is invaluable for verifying and refining existing models of vertebrate flight. However, the relevance of the data to pterosaurs should probably be reviewed by someone who knows the group better than I do - so if you're one of those people, hop (or soar) on over to PLoS ONE and comment on the article!

Reference
Sato, K., Sakamoto, K., Watanuki, Y., Takahashi, A., Katsumata, N., Bost, C., & Weimerskirch, H. (2009). Scaling of soaring seabirds and implications for flight abilities of giant pterosaurs. PLoS ONE, 4 (4) DOI: 10.1371/journal.pone.0005400