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Pterosaur palates in the anatomical record



Attila Osi et al., “New Interpretation of the Palate of Pterosaurs,”
The Anatomical Record: Advances in Integrative Anatomy and
Evolutionary Biology 293, no. 2 (2010): 243-258.

Abstract:

On the basis of a new, three-dimensionally preserved specimen of the
Early Jurassic pterosaur Dorygnathus banthensis we present a
reinterpretation of the pterosaur palate. The hard palate is formed by
the extensive palatal plate of the maxilla and not by the palatine as
has been generally reconstructed. This palatal plate of the maxilla
emarginates the choana rostrally and rostrolaterally as in other
archosaurs and lepidosaurs. The longitudinally elongate and
dorsoventrally flat palatine in Dorygnathus is an isolated bone caudal
to the palatal plate of the maxilla and morphologically and
topographically it resembles that of crocodilians and birds,
respectively. The palatine separates the choana laterally from the
suborbital fenestra demonstrating the homologous nature of the
(primary) choana in all archosaurs and lepidosaurs. Our study
indicates that in basal pterosaurs the pterygo-ectopterygoid fenestra
existed caudal to the suborbital fenestra, which became confluent with
the adductor chamber in pterodactyloids thereby increasing the
relative size of the adductor chamber and hence the mass of the jaw
adductors. The choana in basal pterosaurs was relatively small
compared with the interpterygoid vacuity. With increasing
rostroventral inclination of the quadrates in more derived pterosaurs,
the interpterygoid vacuity was reduced considerably, whereas the
choana increased in size. This exceptional Dorygnathus specimen also
shows a hitherto unknown pair of fenestrae situated at the palatal
contact of the premaxilla-maxilla and might represent the aperture for
the vomeronasal organ.