What lies beneath: SMNS ‘Flathead’ anurognathid wingtips

Earlier and here we looked at deciphering the crushed skull of the ‘flathead’ anurognathid. You might remember in the original description Bennett (2007) mistook a maxilla for a giant sclerotic ring (with teeth!) and a long list of other problems. DGS was able to find a pair of every skull bone and reconstruct them into a skull similar in all respects (except for its exceptional width) to all other anurognathids. Bennett (2007) unfortunately was not able to do this and even had to resort to making up some parts. More unfortunately, the Bennett model has been adopted as correct by a wide variety of pterosaur workers and artists.

Today
we’ll look at the wing membranes and distal wing phalanges that were overlooked in the original description (Fig. 1, Bennett 2007). On a similar note, you might recall yesterday we looked at another Solnhofen pterosaur and fish that betrayed ‘what lies beneath’ by large surface bulges. Similar, but more subtle clues are present here for the careful observer.

Figure 1. Clck to enlarge and animate. Here the buried wing phalanges are shown along with more tail vertebrae and wing membranes. Boosting the contrast brings some close-to-the-surface parts to more prominence.

Figure 1. Clck to enlarge and animate. Here the buried wing phalanges are shown along with more tail vertebrae and wing membranes. Boosting the contrast brings some close-to-the-surface parts to more prominence. If the wing attached to the ankles, there should have been a lot more material folded around the knee. And if there was material around each tibia, I can’t imagine any preparator chipping it away. If you look closely in hi-rez around the left ankle you can see a wing phalanx cross section entrance and exit in the excavated areas. 

These new wing tips
bring this specimen in line with other anurognathids and most other pterosaurs that have four wing phalanges plus a wingtip ungual. Left and right sides match, of course.

I saw this specimen first hand
a few years ago and noticed the left m4.3 was diving beneath the surface, like the English Channel ‘chunnel‘. I showed that to Chris Bennett standing beside me. He didn’t see it that way. Or wouldn’t… not after publishing it with three wing phalanges. The right m4.3/m4.4 knuckle nearly reaches the surface and the distal end of the right m4.4 is broken and clearly visible after surfacing near the right posterior pelvis, but that two was overlooked originally.

Narrow chord wing membrane readily visible here,
not marred by all the prep that removed all the surface matrix within a half inch of the leg bones. As wonderful as this specimen is, it could have used both less prep and more.

References
Bennett SC 2007. A second specimen of the pterosaur Anurognathus ammoni. Paläontologische Zeitschrift 81(4):376-398.

 

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