Where’s the Wing Membrane??

CM 11426 (no. 44 in the Wellnhofer 1970 catalog), Late Jurassic ~150 mya, was considered by Wellnhofer (1970) to be the largest specimen of Pterodactylus micronyx. Never previously tested in any prior analysis, a large phylogenetic analysis shown here actually nests no. 44 far from Pterodactylus. That means this specimen needs new nomenclature. Key to today’s discussion, no. 44 preserves a wing membrane and other soft goodies as in specimens shown here (don’t forget to rollover the image) and here (wait 5 seconds for the second frame).

No. 44 in situ and with wing membranes highlighted. Click to see rollover image and reconstruction.

A Rare Example of Wing Tissue Preservation
Wing membranes are preserved in no. 44 along with neck skin, a propatagium (in front of the elbow) and a uropatagium (behind the thigh). The specimen is nicely laid out in lateral view. The wing membrane is slightly twisted in this specimen as evidenced by the whisp of wing membrane in front of the distal wing finger. This is due to the axial rotation of the wing finger during burial. (Imagine the wing finger flipped over so the convex shape is anterior in life.) Even so, IF the proximal wing membrane did attach at the ankle, as some workers propose, where is it?

The Fact Is: It’s Not There
There is no wing membrane extending to the ankles. No, it extends to the elbow, then takes a slight detour back to the anterior femur. That’s a fact supported by evidence here and elsewhere. The small hole over the torso is either an artifact of preservation or preparation.

I have heard, “well, the wing membrane might not be the same in all pterosaurs.” The fact is: it IS the same in all pterosaurs. No one has shown an iota of evidence for anything different. All evidence supports the “stretched between the wing finger and elbow” hypothesis (Peters 2002). There is no other evidence. It’s not here. It’s not anywhere. That’s the myth of the bat wing pterosaur.

C’mon Guys. Let’s Follow the Evidence!
Note: In No. 44 the wing virtually disappears when folded. That doesn’t happen in Jurassic Park, David Attenborough’s Flying Monsters 3D or Walking With Dinosaurs because the animators added too much wing membrane between the elbow and ankle.

My Offer Still Stands
If anyone can produce evidence for a deep wing membrane, I’ll marry their sister and gladly eat my hat.

As always, I encourage readers to see specimens, make observations and come to your own conclusions. Test. Test. And test again.

Evidence and support in the form of nexus, pdf and jpeg files will be sent to all who request additional data.

Elgin RA, Hone DWE and Frey E 201X (in press). The extent of the pterosaur flight membrane. Acta Palaeontologica Polonica doi: 10.4202/app.2009.0145 online pdf
Peters D 2002. A New Model for the Evolution of the Pterosaur Wing – with a twist. Historical Biology 15: 277-301.
Wellnhofer P 1970. Die Pterodactyloidea (Pterosauria) der Oberjura-Plattenkalke Süddeutschlands. Abhandlungen der Bayerischen Akademie der Wissenschaften, N.F., Munich 141: 1-133.

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