The phylogeny of Dendropsophini (Anura: Hylidae: Hylinae).

The relationships of the hyline tribe Dendropsophini remain poorly studied, with most published analyses dealing with few of the species groups of Dendropsophus. In order to test the monophyly of Dendropsophini, its genera, and the species groups currently recognized in Dendropsophus, we performed a total evidence phylogenetic analysis. The molecular dataset included sequences of three mitochondrial and five nuclear genes from 210 terminals, including 12 outgroup species, the two species of Xenohyla, and 93 of the 108 recognized species of Dendropsophus. The phenomic dataset includes 46 terminals, one per species (34 Dendropsophus, one Xenohyla, and 11 outgroup species). Our results corroborate the monophyly of Dendropsophini and the reciprocal monophyly of Dendropsophus and Xenohyla. Some species groups of Dendropsophus are paraphyletic (the D. microcephalus, D. minimus, and D. parviceps groups, and the D. rubicundulus clade). On the basis of our results, we recognize nine species groups; for three of them (D. leucophyllatus, D. microcephalus, and D. parviceps groups) we recognize some nominal clades to highlight specific morphology or relationships and facilitate species taxonomy. We further discuss the evolution of oviposition site selection, where our results show multiple instances of independent evolution of terrestrial egg clutches during the evolutionary history of Dendropsophus.

Cytogenetic studies on Gonatodes (Reptilia, Squamata, Sphaerodactylidae).

Mitotic and meiotic chromosomes of 5 species of the reptile genus Gonatodes are described by means of conventional staining, banding analyses and in situ hybridization using a synthetic telomeric DNA probe. The amount, location and fluorochrome affinities of constitutive heterochromatin, the number and positions of nucleolus organizer regions, and the patterns of telomeric DNA sequences were determined for most of the species. The karyotypes of G. falconensis and G. taniae from northern Venezuela are distinguished by their extraordinarily reduced diploid chromosome number of 2n = 16, which is the lowest value found so far in reptiles. In contrast to most other reptiles, both species have exclusively large biarmed (meta- and submetacentric) chromosomes. Comparison of the karyotypes of G. falconensis and G. taniae with those of other Gonatodes species indicates that the exceptional 2n = 16 karyotype originated by a series of 8 centric fusions. The karyotypes of G. falconensis and G. taniae are further characterized by the presence of considerable amounts of (TTAGGG)n telomeric sequences in the centromeric regions of all chromosomes. These are probably not only relics of the centric fusion events, but a component of the highly repetitive DNA in the constitutive heterochromatin of the chromosomes. The genome sizes of 4 Gonatodes species were determined using flow cytometry. For comparative purposes, all previously published cytogenetic data on Gonatodes and other sphaerodactylids are included and discussed.

Neurodegeneration-related genes influence C. elegans pharyngeal activity.

Pharyngeal pumping and its reduction following mechanical insult are well-studied C. elegans behaviors. Here, we assessed new applications of pharyngeal pumping assays in the study of neurodegenerative disease and psychiatric illness. We examined five genes implicated in two forms of neurodegeneration, Hereditary Spastic Paraplegia (HSPs) and Alzheimer's Disease (AD), for both baseline pharyngeal pumping and the depressive response after touch stimulus. All five mutants showed reduced baseline pumping rate, suggesting a potential utility of this assay to study neurodegenerative disease on a broad scale. However, regarding the induced pumping response, which has been linked to schizophrenia, only specific genes, the HSP-related atln-1/ Atlastin and the AD-related ptl-1/ tau, showed defects. Together, we highlight two pharyngeal pumping behaviors as genetically distinct, potentially informative settings for understanding the functions of genes linked to neurodegeneration.

The skull of the semi-aquatic neotropical lizard Echinosaura horrida (Gymnophthalmidae: Cercosaurinae) reveals new synapomorphies within Gymnophthalmoidea.

The rough teiid or water cork lizard (Echinosaura horrida) is a small reptile from Colombia and Ecuador placed in a genus that contains eight species and well-known phylogenetic relationships. Here we provide a detailed description and illustrations, bone by bone, of its skull, while we discussed its intraspecific variation by comparing high-resolution computed tomography data from two specimens and the variation within the genus by including previously published data from Echinosaura fischerorum. This allowed to propose putative diagnostic character states for Echinosaura horrida and synapomorphies for Echinosaura. In addition, our discussion includes broader comparisons of new character transformations of the jugal, vomer, orbitosphenoid, and hyoid. These characters are important for diagnosing clades at different levels of the Gymnophthalmoidea phylogeny.

A new giant Atractus (Serpentes: Dipsadidae) from Ecuador, with notes on some other large Amazonian congeners.

We describe a new species of Atractus from Cordillera de los Guacamayos in the Andes of Ecuador. This new species is the largest known species of Atractus, reaching almost 120 cm in total length with a robust habitus. We also use multivariate statistical analyses of morphometric data to look into the taxonomic confusion involving other large, banded/blotched, species of Atractus in Western Amazonia. We show that A. snethlageae has a widespread distribution in Amazonia and has been repeatedly confused with A. major in Ecuador owing to its color polymorphism. Our multivariate statistical analyses support previous suggestions to recognize A. snethlageae as a distinct species relative to A. flammigerus. Taxonomic accounts are provided for both A. major and A. snethlageae including detailed color pattern descriptions. We also find that there are no valid morphological differences to support recognizing A. arangoi as a separate species from A. major; consequently we synonymize the former name with the latter.

A new species of Oreosaurus (Squamata: Gymnophthalmidae) from the Turimiquire Massif, northeastern Venezuela.

We describe a new species of gymnophthalmid lizard, Oreosaurus bisbali sp. nov., from the Turimiquire Massif in northeastern Venezuela. It is one of three reptile species known to be endemic to the region and the fifth species of Oreosaurus from Venezuela. It can be distinguished from all congeners by a combination of rectangular dorsal scales at midbody, having two scales separating femoral pores medially, and lacking a nasoloreal suture. The new species is likely to be restricted in distribution to the highlands of the Turimiquire Massif, which have been significantly degraded by agriculture.

Extended diagnosis of the type species of Pseudogonatodes Ruthven 1915 (Gekkota: Sphaerodactylidae).

Pseudogonatodes furvus is an endemic gecko from the region of the Sierra Nevada de Santa Marta, an isolated massif located in the continental Caribbean region of Colombia. Pseudogonatodes furvus is the type species of the genus, and its morphology and natural history remain poorly known. This lizard was described based on two specimens. After its description, the species has only been mentioned in a handful of taxonomic studies of Pseudogonatodes, in which a few morphological characters of P. furvus have been mentioned. One other paper reported two new localities, without providing new information on the external morphology, especially the lepidosis of the newly obtained specimens. Here we review the external morphology of P. furvus, based on examination of the holotype and six additional specimens. We provide an extended diagnosis and definition, description of holotype, variation, comparisons with other Pseudogonatodes, geographic distribution (adding a fourth locality to the known distribution for the species), and conservation status. Additionally, we describe osteological features for the diagnosis of the genus.

A new diurnal gecko in the genus Gonatodes (Squamata: Sphaerodactylidae) from Margarita Island, Venezuela.

We describe a new species of diurnal gecko, Gonatodes machelae sp. nov., from Cerro El Copey, Margarita Island, Venezuela. The new species is distinguished from all congeners by a combination of the following characters: small size, subcaudal pattern C (1'1''), typically three lateral scale rows on the digits, and aspects of coloration. The new species exhibits polychromatism similar to what has been described in some other species of Gonatodes. It is found in humid forests and shrublands from about 450 m to 900 m above sea level.