Species Limits And Phylogenetic Systematic Of The Diurnal Geckos Of The Genus Gonatodes (Squamata: Sphaerodactylidae)

The genus Gonatodes (family Sphaerodactylidae) is a diverse of group of about 20 species currently recognized of mostly diurnal geckos that are collectively distributed from southern Mexico to Brazil and Bolivia, and also including most of the Caribbean Islands. The systematics of this group remains poorly studied with published contributions limited mostly to the original species descriptions, natural history notes, and a recent, yet largely incomplete, molecular phylogeny. In this work, several contributions to the systematics of this genus are made. The first chapter is a general introduction to the group. Chapter 2 is a phylogeographic study of the G. vittatus complex in northern Venezuela. The most significant results from this chapter suggest mitochondrial introgression between G. petersi and G. vittatus at a novel contact zone. In addition to this, a new species is this complex is discovered and supported by both morphological and molecular data. Chapter 3 is a systematic study of the genus Gonatodes in the Guayana Shield. Two new species in this region are discovered and described, and molecular data supports a monophyletic radiation of the genus in the region. In Chapter 4 a novel approach to delimit species boundaries is proposed and tested in a group of species of Gonatodes found in montane habitats of Venezuela. This new approach uses a combination of different data including morphological characters, mitochondrial markers, and GIS-based ecological niche modeling to infer ecological barriers. Chapter 5 is a discussion on the phylogenetic relationships of the genus Gonatodes focusing in the major clades and the position of G. antillensis, which is the only known nocturnal species of Gonatodes. The molecular data supports inclusion of this species in Gonatodes and the notion that it has re-evolved character states associated with nocturnal life (elliptical pupil and use of vocalizations).