Parallelism and Integrated Design in the Foot Structure of Gekkonine and Diplodactyline Geckos

Abstract

The Gekkonidae is divided into 4 subfamilies (Eublepharinae, Diplodactylinae, Gekkoninae and Sphaerodactylinae) and various interrelationships of these taxa were proposed. On a cladistic basis the Diplodactylinae may be regarded either as the sister group of the Gekkoninae or the sister group of the Gekkoninae and Sphaerodactylinae. With respect to diversity within the family the diplodactylines and gekkonines have occuppied the greatest number of habitat types and their locomotor systems have developed independently but in similar ways. These 2 subfamilies have radiated largely in isolation from each other and in many instances parallelisms have occurred. With respect to locomotor mechanisms these parallelisms may be linked with the possession of a key innovation-a spinose Oberhautchen. The apparent similarity may be due to the way of life of the organisms concerned and within the family near duplicates were produced in isolation. This was evident in foot structure and reflects the method of contact of the organism with the substrate and exemplifies the interdependence of substrate type, locomotor pattern, morphology and behavior. Some functional correlates associated with different foot types were discussed.