Two recent blog posts by J. Headden, illustrations by M. Witton and various other odd reconstructions of the skull of the SMNS anurognathid (Bennett 2007), the flathead pterosaur, prompted today’s post. I realize I have not provided sufficient clear imagery and so, here it is (in rollover images or see below).
You’re looking at what appears to be a complete skull crushed ventrally with all parts intact and articulated. That is not the case. If so, you’d end up with a monster bearing little resemblance to other anurognathids and other pterosaurs in general (aka Bennett’s reconstruction, fig. 6 left). There was some shifting during taphonomy as will be made clear in the following photos. Reconstructing the parts produces a very nice anurognathid sharing most traits with other anurognathids (fig. 6 right), but the skull has a flatter morphology.
I realize the bones I found in this specimen are difficult to see. So today I present some of them as well as I possibly can (see figs. below). You can (and I encourage you to) use a rollover on the reptile evolution page on the flathead anurognathid here.
Bennett (2007) described this specimen and created reconstructions (fig. 6) in which his giant scleral ring was in the anterior half of the skull, the antorbital fenestra was relegated to a tiny zone bounded by bones he claimed he never found and the skull roof was as wide as any turtle’s with widely separated upper temporal fenestrae. Such a reconstruction is at odds with all other pterosaur skulls. Recall that Bennett also invoked the idea that the very wide frontal bones of the SMNS specimen were decayed centrally, providing windows to whatever bones were beneath them. Not so. His frontal bones are composed laterally on the left by a dorsal lacrimal piece (fig. 5) and medially by the narrow nasals (fig. 3). That’s a large corner of an ectopalatine seen through the bones.
If you still can’t see the imagery I indicate above, please visit these rollover images. That way you won’t have to shift back and forth to compare images. You can also see the palate and other bones on the same web page.
Using DGS (digital graphic segregation, I was able to find symmetrical pairs for every bone in the skull, despite the layering of cranial bones atop displaced facial and palatal bones. All the bones, even those of the palate, resemble those in other anurognathid palates. Moreover, in the case of the SMNS anurognathid the palatal elements criss-cross and reinforce each other, providing maximum strength with minimum weight. The same cannot be said of the Bennett reconstruction.
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.