Thursday, June 18, 2009

Dr. Mark Witton weighs in on Pterosaur wings

It seems our recsent discussions on Pterosaur reconstructions, in particular wing attachments, has attracted the attention of at least one expert, Dr. Mark Witton. (To catch up on these discussions, they can are in the comment sections of these posts here and here).

For those of you who have never heard of Mark Witton, he is an English Palaeontologist who specializes in Pterosaurs. He has done a lot of collaberative work with internet biology/palaeontology guru Darren Naish, but also made several discoveries on his own.

Of more interest given our palaeo-art spin here at ART Evolved, Dr. Witton is an active (and very talented, I might add) palaeo artist. You can see his work here on his flickr page (including a Pterosaur gallery). The lovely picture above being a more outlandish example of his work (I choose it as I'm under the impression the young man bending over to retrieve his hat is a self portrait of Dr. Witton).

Given his expertise in both the scientific field of Pterosaurs and also in how to reconstruct them, he wanted to add his opinion to the discussion. As he lacked a google account Dr. Witton emailed our member Zach, who himself was unable to post the email. So I have been entrusted with this task.

So without further ado Dr. Mark Witton's comment:

Hi Zach,

I was just checking out some bits online and came across the ART Evolved website. Seeing that you're doing pterosaurs next, I checked out what was being said and noticed that there were some discussions about membrane attachments. Seeing as the concensus between your commenters was that there was no concensus, I think you need to reconsider your ideas.

There are at least 3 reconstructions that are regularly discussed, but only one is worth any salt. For this reason, all my papers (at least, unless I've totally forgotten something) say that the ankle-based attachment is best supported.

Look, here's a quote from Witton and Naish (2008):

"...evidence from anurognathids, campylognathoidids, rhamphorhynchids,> ctenochasmatoids and non-azhdarchid azhdarchoids [86]–[91] indicates that ankle-attached wing configurations are more accurate."

In a nutshell: there is _no_ support for a supports a hip attachment, one specimen may show a knee attachment (but it's ambiguous at best), whereas specimens of Eudimorphodon, Anurognathus, Jeholopterus, Rhamphorhynchus, Sordes, Beipopterus and a tapejarid (at least, there may be some I've forgotten) all give either hints of an ankle attachment or show it quite convincingly.

Hence, if you draw any other type of brachiopatagial attachment on your pterosaurs, you're ignoring the wealth of evidence in it's favour.

Darren Naish gave more detail on this a while back, and not much has changed since then: The question of membrane shape has is different, nowadays: did they taper in close to the body before hitting the ankle, or extend in a broader fashion?

That's a considerably harder question to answer. I did try to put this on the blog, but I couldn't post it as I don't have a Google account. In any case, it may be an idea to pass it onto your chums so everyone has the same data. Anyway, I'm looking forward to seeing the results, and I might have something new for my own site up soon. Ish.



I apologize to both Zach and Dr. Witton if I garbled the formatting here a bit. The version I received was a HUGE mess, due to gmail replacing spaces and enters with "<"s.