Variation of cranial bone sculpturing in Gekkota

Abstract

Cranial bone sculpturing has not been evaluated in Gekkota. The first aim of this study was to identify the presence of cranial bone sculpturing by completion of a bone by bone analysis and then optimizing the character information onto a known molecular tree from Gamble et al. (2012). All three identified types of cranial bone sculpturing were identified in at least one member of Gekkota. It was found to occur almost exclusively on the dermatocranium, except for Chondrodactylus bibronii. Upon optimization of the character, there was only one family found to be entirely smooth (Pygopodidae), while the remaining have at least one occurrence of cranial bone sculpturing. Regardless, the predominant character state for cranial bones remains to be smooth. The second aim of this study was to investigate the relationship between cranial size and bone sculpturing, in both an intra- and interspecific context. Smooth and grooved cranial bone sculpturing can be found on any skull size, whereas pitted and grooved cranial bone sculpturing is found on the medium to larger sized skulls, excluding Matoatoa. Rugose cranial bone sculpturing develops from an almost smooth cranial surface to the extreme morphology seen in the skeletally mature individual. Pitted cranial bone sculpturing develops comparably to that observed in crocodiles, grooved sculpturing that progresses to the extreme morphology observed in the skeletally mature individual. Confirming variation of cranial bone sculpturing in Gekkota.