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On Wednesday, July 24, 2002, at 06:39 AM, Ronald Orenstein wrote:

At 09:49 AM 24/07/02 +0100, darren.naish@port.ac.uk wrote:
Moving on to pterosaurs, I am not sure that Kellner and
Campos are right about _Thalassodromeus_ being a skim-
feeder. There are various reasons for this.

May we know what they are?

Yeah, I'm curious too. I can't remember where I've read this but I think I've heard that in skimmers, the beak has different cross-sectional shapes along its length. The end of the beak is teardrop-shaped this being the shape that provides minimum water resistance to a submerged object, however farther up the beak has sharp leading and trailing edges- this shape being the best shape to cut through the water at the surface where the dynamics are totally different. If you saw something like this reflected in the lower jaw of the pterosaur I think you'd have a good case. The other thing is the disparity in jaw length, which is the most obviously unusual feature of skimmers.