SVP abstracts – Pterosaur pterygoids under a CT scanner

Chen et al. pulled out their CT scanner
to look at derived pterosaur palates.

From the abstract:
“Here we shed new light on the palatal complex from two wel-preserved specimens of the Early Cretaceous pterosaur Hamipterus tianshanensis. In the new material, the pterygoid fused with the opposite one along the midline. The lateral pterygoid process shows a unique shape, and the other two processes form the pterygoid fenestrae ventrally. Besides, the lateral process fused to the medial aspect of the jugal during the ontogeny.  We discovered that the flat ectopterygoid overlays dorsally the pterygoid, and two sides of the ectopterygoid fused to midline was the same place that pterygoids fused. Hence, the ectopterygoid in Hamipterus also forms the anterior margin of the pterygoid fenestrae dorsally.”

The evolution of the pterosaur palate from Eudimorphodon to Haopterus.

Figure 1. The evolution of the pterosaur palate from Eudimorphodon to Haopterus.

Chen et al. continue:
“This complicated structure of pterygoid and ectopterygoid can only be observed in the dorsal view of palatal complex, and it consists with the situation in some previous studies. The ectopterygoids in Hongshanopterus, Kunpengopterus, Caupedactylus, Tupuxuara, and Anhanguera overlay dorsally the pterygoids as well. Our study indicates that this complex structure probably exists in Gnathosaurus, Dsungaripterus, Tropeognathus, and Coloborhynchus by comparing with Hamipterus, Caupedactylus, and Anhanguera. Thus, we assume that the ectopterygoid extend across the pterygoid dorsally very early, at least in Kunpengopterus, and that this situation probably is a synapomorphy in the Monofenastrata.”

No need to assume anything.
This was all covered several years ago online in an 8-part series ending here.

Oddly
nowhere in Chen et al. do they discuss the palatine. Peters 2000 was the first to document that the palatine was not the palatal portion of the maxilla, as all prior workers from Bennett to Welllnhofer asserted. Rather the palatine appeared as a slender anteroposterior bone articulating with and often fusing with the shorter ectopterygoid at right angles creating a new bone, which Peters 2000 named ‘the ectopalatine’.
Osi, Prondvai, Frey and Pohl 2010
claimed to have a new interpretation of the palate of pterosaurs, but Peters 2000 preceded them by a decade. The authors both acknowledged and dismissed the earlier finding in their paper. Everyone wants to make the discovery. No one wants to make the confirmation. 
Pinheiro and Schultz 2012
recently reported on an “unusual” pterosaur palate from Brazil. They correctly identified the palatal shelves as belonging to the maxilla, separated only by the vomers. They correctly identified the pterygoids. They correctly identified the palatines in most of their pterosaurs, but they did not understand that the palatines and ectopterygoids both fuse and diverge diagonally in Pteranodon (so their ectopterygoid is the ectopalatine). This becomes obvious after a study of Germanodactylus palates, again from several years ago (2012).
Figure 1. Click to enlarge. Evolution of the pterosaur palate from Scaphognathus to Pterodactylus and Germanodactylus.

Figure 2. Click to enlarge. Evolution of the pterosaur palate from Scaphognathus to Pterodactylus and Germanodactylus.

References
Chen et al.  2019. Shed new light on the configuration of the pterygoid and ectopterygoid in derived pterosaurs through CT scanning. Journal of Vertebrate Paleontology abstracts.
Osi A, Prondvai E, Frey E and Pohl B 2010. New Interpretation of the Palate of Pterosaurs. The Anatomical Record 293: 243-258.
Peters D 2000. A Redescription of Four Prolacertiform Genera and Implications for Pterosaur Phylogenesis. Rivista Italiana di Paleontologia e Stratigrafia 106 (3): 293–336.
Pinheiro FL, Schultz CL 2012. An Unusual Pterosaur Specimen (Pterodactyloidea, ?Azhdarchoidea) from the Early Cretaceous Romualdo Formation of Brazil, and the Evolution of the Pterodactyloid Palate. PLoS ONE 7(11): e50088. doi:10.1371/journal.pone.0050088

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