Evolution of the Pterosaur Palate – part 8: Tapejaridae and Pteranodontidae

Earlier we looked at basal pterosaur palatesdimorphodontoid palatescampylognathoid palates, pre-azhdarchid palates, pre-ctenochasmatids, pre-ornithocheirids, and pre-Pterodactylus + Germanodactylus. Here in part 8 we’ll look at the pterosaur palate from Germanodactylus to Tapejara and Pteranodon (Fig. 1), following the phylogenetic order recovered in the large pterosaur tree).

 

Figure 1. The palates of several Tapejaridae and Pteranodontidae, both evolving from Germananodactylus.

Figure 1. The palates of several Tapejaridae and Pteranodontidae, both evolving from Germananodactylus.

Phobetor/Noripterus
Distinct from Germanodactylus rhamphastinus the skull of Phobetor/Noripterus was much sharper anteriorly. The palate was broad the teeth were partly covered by palate bone.

Sinopterus
Distinct from Phobetor, the palate of Sinopterus had no teeth, other than the single tooth at the tip (also found in dsungaripterids, but not preserved in Phobetor). The pterygoid was long and gracile. The ectopalatine was smaller, gracile and both processes were directed toward the cheek. The basipterygoids were fused to form a single broad bone.

Tapejara
Distinct from Sinopterus, the palate of Tapejara had a post premaxilla depression (that is, deeper in ventral view). The pterygoids were shorter. The quadrates were larger.

The Karlsruhe specimen of Germanodactylus 
Distinct from Germanodactylus rhamphastinus the pterygoids were much longer in the Karlsruhe specimen. Both processes of the ectopalatine contacted the cheek. The rostrum teeth were merged to become one tooth.

Nyctosaurus
Distinct from the Karlsruhe specimen, Nyctosaurus had no teeth, more of a maxillary palate and a smaller pterygoid. In the FHSM the anterior pterygoid was expanded. In the FMNH specimen the anterior pterygoid was sharp.

Pteranodon
Distinct from Nyctosaurus, the palate of Pteranodon was larger overall and sharper. The pterygoid lateral process was much larger and the medial processes were smaller. Posteriorly the pterygoids completely filled the former space between the quadrates and the basipterygoids here fused to form a single narrow process. Both processes of the ectopalatine were fused medially, separated only near the cheek. The vomer was completely fused to the maxillary palate plates.

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.

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