Meeting Abstract
Gliding behavior evolved independently at least three times in geckos, presumably in a coevolution of complex phenotypic characters associated with crypsis, gliding, and a behavioral trait known as ‘voluntary leap’; the Indopacific gecko group (IGG) includes forms that developed novel peramorphic traits, suggesting an evolutionary trend towards skull reinforcement. These complex skull traits (namely synostosis, development of crests, and hypermorphosis of skull bones) have been interpreted as adaptation to feeding biomechanics; however, they might also indicate some reinforcement of the skull to provide additional protection to the brain and special sense organs from landing impacts after gliding or jumping. To test this idea, skulls from several IGG taxa were analyzed using HRCT data and X-rays. Changes in the axial axial skeleton include presence of a supraoccipital dorsal process and a prefrontal canthal crest in the gliding genus Ptychozoon and closely related forms from Luperosaurus. Changes are not limited to the skull, for gliders also exhibit expanded wrists and ankles, as well as a reduction in the height of vertebral arches and modifications of ribcage morphology. Some of these traits are also found in non-gliding taxa (e.g. Gekko), which suggests that these traits are exaptations that coevolved with behavioral traits, such as ‘voluntary leap’ performance, prior to the origin of gliding.
