Reptilian ear 3D morphometric data

Reptiles, including birds, exhibit a range of behaviorally significant
adaptations reflected in changes to the structure of the inner ear. These
adaptations include capacity for flight and sensitivity to high-frequency
sound. We used 3D morphometric analyses of a large sample of extant and
extinct reptiles to investigate inner-ear correlates of locomotor ability
and hearing acuity. Statistical analyses revealed three vestibular
morphotypes, best explained by locomotor categories: quadrupeds, bipeds
and simple fliers (including bipedal non-avialan dinosaurs), and
high-maneuverability fliers. Troodontids fall with Archaeopteryx among
extant low-maneuverability fliers. Analyses of cochlear shape revealed a
single instance of elongation, on the stem of Archosauria. We suggest that
this transformation coincided with the origin of high-pitched juvenile
location, alarm, and hatching-synchronization calls, and adult responses
to them.