Cladistic analysis of the Gekkota(Reptilia) by means of craniological data

Abstract (Summary)
The morphological variation of the gekkotan skull as visualized through dorsal and lateral views of a large sample of skulls (164 species, 68% of all gekkotan genera) was analyzed using geometric morphometrics. I describe skull changes using variables associated with the contour variations (uniform components) as well as localized changes (partial warps). I defined dietary categories based on information published for 105 species. These categories, together with phylogenetic affinities were used as descriptors of the skull shape variables in subsequent statistical analyses. Changes based on the morphological variables are described and discussed in an ecological and phylogenetic context.

All available information about gekkotan cranial variation was combined in a single cladistic analysis including 54 taxa, 51 are gekkotans representing the 7 recognized families and three species belonging to Gekkonomorpha, Iguania and Autarchoglossa. I assembled a large character list, consisting of 326 previously used morphological characters and 68 novel primary homologies (394 total). A topology test (Templeton test) was used to compare the results from the morphological analysis with recent molecular hypothesis. Groups recovered that are congruent in both analyses were defined with unambiguous synapomorphies. Finally paedomorphosis and miniaturization processes were reviewed within the Gekkota, discussing the modifications in skull structure.