What is the latest consensus on the position of the pteroid and it's effect on the propatagium? I'm a natural history illustrator (mostly birds and dinosaurs, oops, I mean avian and non-avian dinosaurs!) and not being a pterosaur expert (just a plain zoology degree) I'm a little confused as to which way to point the pteroid in my paintings. Chris Bennett was pretty convincing in rebutting Unwin's view in an email conversation we had, but I would like to get as wide ranging a view point as I can, to be fair to all parties.
Any ideas?
Many thanks,
Andrew Plant,
Melbourne,
Australia.

Well Andrew, Dino Frey has a new paper just out on this very problem with a new genus of almost unspellable nytosauroid pterosaur (Muzquizopteryx) that has a complete wrist preserved in articulation (with a sesamoid bone for those in the know). Basically this shows that Chris Bennett was right on the money, and that the pteroid does indeed articulate in such a way that it faces medially.

(For the uninitiated, the pteroid is a special wristbone in pterosaurs that supports a kind of 'front-wing' called the propatagium. There has long been a debate about how exactly it functioned).

In short, the propatagium is therefore (relatively) small and probably runs only from the wrist to shoulder. Of course, there might be an additional small membrane to the outside of the wrist, and close in, it might reach partly onto the neck.

However, it is not the elongate and enlarged structure that Matt Wilkinson and colleagues proposed (and has been floating around in one way or another for  the last 20 years). I would imagine that in a few years this will pretty much be the standard view of the pteroid as previously we have always lacked concrete evidence for the natural position of the pteroid. Obviously it is attached to a flexible structure in the propatagium so after death is is likely to be pulled out of position by post mortem contractions, and with an apparent sesamoid of only cartilidge in basal pterosaurs, its not surprising that there were 2 places for the pteroid to articulate and several ways it could face based on the (then) available evidence.

Still, I would imagine there will still be some debate as to the flexibility of the pteroid and just how far it could move and in what directions, so there is still plenty for pterosaur researchers to argue about with the pteroid!

And another note of caution: this new specimen tells us how the pteroid was oriented in ONE SPECIMEN.  We can legitimately generalise that finding to the species, and somewhat higher, but it's hard to say how far up the tree.  It certainly isn't enough, on its own, for us to draw a firm conclusion about the use of this bone across the whole of Pterosauria, which is a big clade with enormous morphological disparity.

(For the same reason, I am wary of statements like "sauropods were terrestrial rather than aquatic".  Sure, some were; but that's a bit like saying "mammals are terrestrial".  In among all the cows, tigers and rats, there are also hippos, not to mention whales.  Who knows whether some sauropod group -- not yet known, or known but not yet recognised -- was as aquatic as hippos?)

Thats true Mike, but in this case I think its fairly sound to extend the principle across the clade. Basically we only had two places and two ways to articulate the pteroid. The sesamoid bone in the wrist was hypothesised, and if present would have forced the pteroid into slot '2' and we would be left with the situation described above.

The fact that we now have several sesamoids known and articulated wrists (I have simply described the best) in different families adds a lot of weight to this. There were alos all fairly derived pterodactyloids and the 'forward' pteroid has been shown to produce greater lift and control than a laterally facing one. Therefore it would be very odd if the basal rhamphorhyncoids had a forward pteroid and the pterodactyloids abandonned it to reduce their flight capability!

Just to jump in with Dave, flight adaptations are normally very conservative once thay have evolved - the alula in birds is broadly analagous to the pteroid, and that is remarkably consistent thoughout flying birds.