Phylogenetic relationships of a new genus and species of microteiid lizard from the Atlantic forest of north-eastern Brazil (Squamata, Gymnophthalmidae)

Abstract

A new genus and species of a short limbed and slightly elongate gymnophthalmid lizard is described from the Atlantic rain forests of north-eastern Brazil. The new genus is also characterized by short and stout pentadactyl limbs, presence of prefrontals, absence of frontoparietals, distinctive ear opening and eyelid, two pairs of genials, a distinct collar, smooth, quadrangular, dorsal scales, quadrangular ventrals, fused postfrontal and postorbital bones, and two pairs of sternal ribs. The geographical distribution of the new taxon extends from the state of Rio Grande do Norte to the northern bank of the Rio São Francisco in the state of Alagoas. All specimens were obtained in leaf litter, an observation which agrees with the fossorial habits suggested by the body shape and massive aspect of the head of this species. A phylogenetic analysis based on external morphology, osteology, and molecular data recovered the new lizard as the sister genus to Anotosaura , and Colobosauroides as the sister group to these two.

A New Genus of Microteiid Lizard from the Caparaó Mountains, Southeastern Brazil, with a Discussion of Relationships among Gymnophthalminae (Squamata)

“…These scales are wider than long in Colobodactylus and Heterodactylus whereas they are longer than wide in all other Heterodactylini. As previously reported this difference is probably due to a scale rearrangement in Heterodactylus and Colobodactylus in which parietals (and the interparietal in Colobodactylus) are divided and their posterior regions incorporated into the highly conspicuous occipitals that characterize both genera (Rodrigues et al, 2005). The parietals of Caparaonia are not so reduced as those of Colobodactylus and Heterodactylus, but they are certainly shorter than those of other Heterodactylini.…”

“…Scale counts and scale nomenclature are according to Rodrigues et al (2007) and osteological nomenclature follows Presch (1980), Estes et al (1988), Bell et al (2003), and Rodrigues et al (2005Rodrigues et al ( , 2007. We considered occipitals the one or two pairs of transversely enlarged scales following interparietal and parietals.…”

“…The family currently includes the subfamilies Alopoglossinae, Rhachisaurinae, Gymnophthalminae, and Cercosaurinae, according to Pellegrino et al (2001) and Rodrigues et al (2005Rodrigues et al ( , 2007. Castoe et al (2004) also attributed subfamilial rank to the Ecpleopinae 4 contrary to the tribal rank among the Cercosaurinae proposed by Pellegrino et al (2001) and Rodrigues et al (2005Rodrigues et al ( , 2007.…”

“…At the time, Vanzolini personally told the senior author that the description of the new taxon was not an easy task because it involved complications, probably in the synonymy of the genera Colobosaura and Colobodactylus. It is important to say that this actually was a fairly good approximation of its relationships because microteiid systematics was chaotic due to the widespread use of convergent morphological traits in the classification of the family (see Rodrigues et al, 2005). It was only recently, in the process of describing the new gymnophthalmid genus Alexandresaurus Rodrigues et al, 2007, that the senior author discovered that these specimens (MZUSP 55926 and USNM 008080-field number) along with other specimens of Colobosaura and Heterodactylus were in very bad condition.…”

“…Castoe et al (2004), based on Bayesian analyses of a slightly improved molecular dataset than those used by Pellegrino et al (2001), dissolved the tribes because monophyly of Gymnophthalmini was not recovered. Contrarily, Rodrigues et al (2005Rodrigues et al ( , 2007, based on a combined analyses of molecular and morphological characters, bring support to this basic division in Gymnophthalminae. However, as the last study was addressed to recover the position of Alexandresaurus among the Heterodactylini, and not to test its monophyly, only two of the eight genera of Gymnophthalmini admitted at the time were represented in those analyses.…”