Examples from Elgin, Hone and Frey (in press) which they purport to demonstrate the wing trailing edge attaching to the ankle. In fact, none of these examples do so. Note: Hone's blog: http://pterosaur-net.blogspot.com/2010/09/on-wing-membrane-and-ankle-attachment.html exchanged many of the images since the original post.

A. the darkwing specimen of Rhamphrohynchus (JME SOS 47484). Note the trailing edge is directed toward the elbow, as in the Peters (2001) model and the Zittel wing. It does not curve toward the ankle. The authors missed the curve inboard of the elbow. The pink area is on a lower plane.

B. Jeholopterus (IVPP V 12705). The authors failed to use the counterplate and traced the proximal membrane extending to the elbow and the wingtip attaching to the ankle!!

C. The “Vienna specimen” (NHMW 1975/1756) of Pterodactylus. Here the proximal attachment points could not be more clear, so the authors invented "membrane shrinkage" to explain the reduction of the membrane near the elbow. Notice the rest of the wing membrane failed to shrink.

D. A new specimen attributed (Bennett  2007) to Anurognathus. Here again the authors traced the trailing edge directly to the elbow without a tibia connection.

E. Eosipterus (GMV 2117). The only portions of the patchy wing membrane traced by the authors followed the Peters (2001) model precisely with no indication of a membrane lateral to the tibia

F. Sordes (PIN 2585/3). The authors did not understand that the medial trailing edge was torn from the antebrachium, which forms the trailing edge leading toward the ankle, the continues on as an apparent fiber-embedded uropatagium. Details here. No other pterosaur uropatagium has aktinofibrils. The actual uropatagia are smaller, matching those of other pterosaurs.

G. An unnamed specimen (SMNK PAL 3830) in which a swath of torn and disassociated wing membrane crosses both legs at an angle. This specimen provides no data as to how this membrane was connected to anything on the pterosaur, including either tibia.  However the membrane itself does not extend beyond a narrow rectangular band across its entire length, matching the Peters (2001) hypothesis, not the deep triangle of tissue imagined by Elgin, Hone and Frey (2010).

Figure 5 of Elgin, Hone and Frey (2010, above) claimed to show examples of pronounced contraction of the wing in specimens of Rhamphorhynchus No. 11 (BSP 1938 I 503a) and Jeholopterus (CAGS IG 02-81).

In the BSP specimen distinct tones clearly show a curving trailing edge of the wing membrane extending from the first interphalangeal joint inboard to the knee in both wings, but the authors ignored this data in their tracing. More to the point, this specimen does not present an example of a contracted membrane, but one in which the distal wing bones have been flipped over, twisting the membrane beneath them. Note the brachiopatagium appears in front of the wing fingers in this specimen. Furthermore, no indication of a membrane lateral to either tibia is present.

In the CAGS specimen tracing, Elgin, Hone and Frey (2010:fig. 5b2) provided no demarcation between the dermal pelage and the wing membranes. They considered this specimen, “a clear example of the extent to which a flexible membrane can contract post-mortem.” Not true. Details here. As in the BSP specimen (see above), the humeri and antebrachia were rotated as a unit 180º from their natural orientations, tearing the wing membrane into several overlapping pieces and disarticulating the distal wing phalanges. The wing membrane is not contracted here. It is torn to pieces. What appears to be a propatagium with aktinofibrils is indeed a propatagium, but it is located above a large segment of similarly shaped brachiopatagium provided with aktinofibrils that show through. No propatagium has aktinofibrils. Key to the present hypothesis is the presence of a narrow chord wing membrane, even if in pieces, and inboard fuselage fillet that, “does not show an ankle attachment,” as acknowledged by Elgin, Hone and Frey (2010).

The use of this image in a scientific argument is specifically warranted and falls under the doctrine of Fair Usage. It is in the interpretation of the photograph/image itself that the argument and opinions are found. Thus only the image itself, not a representation or interpretation of same, can be used as evidence in this situation and others like it.

Bennett SC 2007b. A second specimen of the pterosaur Anurognathus ammoni. Paläontologische Zeitschrift 81: 376-398.

Elgin RA, Hone DWE and Frey E 2011. The extent of the pterosaur flight membrane. Acta Palaeontologica Polonica 56 (1), 2011: 99-111. doi: 10.4202/app.2009.0145

Peters D 2002. A New Model for the Evolution of the Pterosaur Wing – with a twist. - Historical Biology 15: 277–301.