A welcome and recent paper on pterosaur skull morphospace found the anurognathid skull of Bennett (2007) to be “highly aberrant” an “outlier” and “highly divergent.” How can this happen when evolution is supposed to be a gradual process?
Guys, the Bennett anurognathid reconstruction is WRONG!
As I blogged earlier, it’s an invented, imagined monster misidentifying the toothy maxilla as the purported super-sized and preserved edge-on sclerotic ring among several other problems all detailed here.
A correct skull would nest closer to the morpho-cloud of the other pterosaurs. Several anurognathid skulls, including more primitive taxa, would show the developmental path from basal taxa, no doubt finding its base deeper within the morphospace cloud.
A recent blog featured the vampire pterosaur, Jeholopterus. This opened comment on the Dinosaur Mailing List, most of it negative. Some comments recalled earlier mistakes I made using the DGS technique. To these people early mistakes ruin the DGS technique for all time. Is this prejudicial? Just because I stole a Twinkie in grade school does not (or does it?) brand me a thief for all time. IMHO it would be better if every incidence was judged independently, on its own merits. That would be more scientific. That’s how I operate. Credit where credit is due. Criticism where criticism is due.
As noted above, the DGS technique enabled the identification of every bone in the skull of the flat-headed pterosaur – and their symmetrical counterparts – and all these bones all fit well within standard anurognathid skull patterns. In counterpoint the Bennett reconstruction broke ALL the rules. Some bones he reports he had to invent.
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.
Bennett SC 2007. A second specimen of the pterosaur Anurognathus ammoni. Paläontologische Zeitschrift 81(4):376-398.
Foth C, Brusatte SL and Butler RJ 2012. Do different disparity proxies converge on a common signal? Insights from the cranial morphometrics and evolutionary history of Pterosauria (Diapsida: Archosauria). Journal of Evolutionary Biology (advance online publication) doi: 10.1111/j.1420-9101.2012.02479.x