While basal pterosaurs had lots of teeth, and certain derived pterosaurs, like SoS 2179 and Pterodaustro had dozens to hundreds of teeth, certain pteroaurs appear to have been toothless – or so they say…
I’ll just cut to the chase.
Apparently “toothless” pterosaurs, like Pteranodon, Nyctosaurus and Tapejara actually had one tooth at the tip of the premaxilla and one tooth at the tip of the dentary. That’s how the tips were able to become and remain so sharp. Like the wing ungual and manual digit V, these single teeth have been overlooked by all prior pterosaur workers. The evolution of these single anteriorly-directed teetth can be documented in predecessor taxa among the germanodactylids, but it is still not clear whether one tooth became smaller or the two anterior teeth fused to become one. It seems reasonable that these teeth would be replaced with new teeth at the root, but this has not yet been documented. In the images below, if there was a “next” tooth, it is not apparent.
Figure 1. Click to enlarge. The tooth at the tip the mandible of KUVP 66130, a nyctosaurid.
Figure 2. Click to enlarge. The tooth at the tip of the rostrum of KUVP 66130, a nyctosaurid.
In the nyctosaurids above the dentary and premaxillary tooth tips are shown.
Figure 3. Click to enlarge. The tooth at the tip of the rostrum of Tapejara.
The Evolution of “Toothless” Pterosaurs
In several pterosaurs the medial or first premaxillary tooth was procumbent. It angled forward as well as downward. In B St 1967 I 276 (No. 6 of Wellnhofer 1970), the tiniest pterosaur, the anterior premaxillary tooth was procumbent.
Figure 4. The rostrum of No. 6 in which the teeth at the tip were procumbent, but not anteriorly oriented.
In the specimen from the Senckenberg-Museum Frankfurt a. M. No. 4072, (No. 12 of Wellnhofer 1970) the anterior tooth was oriented further anteriorly and may have been a single tooth.
Figure 5. The jaw tips of No. 12
In Germanodactylus the SMNK-PAL 6592 specimen, the anterior premaxillary and dentary teeth were fully anterior in orientation.
Figure 6. Germanodactylus skull with anteriorly-oriented jaw tips
Figure 7. Germanodactylus SMNK skull drawing showing anteriorly-oriented teeth at jaw tips.
You’ll find anteriorly oriented teeth in all germanodactylids and their sharp-snouted descendants including dsungaripeterids, shenzhoupterids, tapejarids, nyctosaurids, eopteranodontids and pteranodontids. I have not been able to closely examine the anterior jaws of azhdarchids, but photographic examination appears to show tiny (< 1 mm) teeth lining the jaws of Quetzalcoatlus sp.
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.
The Pterosaur Heresies 