The genus Stenocercus includes over 50 species, distributed mainly in elevated areas in the Andes and adjacent lowlands, with only a few taxa known to occur in Brazil. The easternmost populations of the genus are poorly studied and represented in collections. Herein we describe Stenocercus quinarius sp. n. from northwestern Minas Gerais and western Bahia states, and Stenocercus squarrosus sp. n. from the southern portion of the state of Piauí, two previously poorly sampled areas in central and northeastern Brazil. The two new species seem closely related to Stenocercus dumerilii and Stenocercus tricristatus, but are easily diagnosed from all Stenocercus and from each other based on morphometric and meristic characters. The distribution patterns and possible phylogenetic affinities of the eastermost, pyramidal headed Stenocercus group are discussed, along with an overview of distribution patterns of the genus in extra-amazonian open domains.

An analysis of specimens deposited in herpetological collections and identified as Physalaemus fuscomaculatus demonstrated that these differ from the types of this taxon, Eupemphix fuscomaculatus, Consequently, the taxonomic status of Gomphobates marmoratus and Eupemphix fuscomaculatus was revised based on the types and on data in the literature. Gomphobates marmoratus is associated to the genus Physalaemus, as Physalaemus marmoratus, and refers to specimens previously identified as Physalaemus fuscomaculatus, Additionally, Eupemphix fuscomaculatus is associated to the genus Pleurodema in the combination Pleurodema fuscomaculata.

We re-analyzed the most recent morphological data matrix for Pleurodira with inclusion of the Upper Cretaceous Brazilian pleurodiran turtle, Bauruemys elegans (Suárez, 1969), as new Operational Taxonomic Unit. An exhaustive search based on 50 characters for 11 taxa was performed to asses the phylogenetic relationships within the Pelomedusoides and a single most parsimonious tree of 64 steps was found. This new phylogenetic hypothesis places B. elegans as a basal form of Podocnemididae and is used to found a new biogeographic model for the Pelomedusoides. The biogeographical approach was performed with direct analysis of vicariance, using historical sequence of vicariance and phylogenetic information to construct an event-based model. Thus, inspection of distributions maps of Pelomedusoides and the phylogenetic arrangement proposed here were used to correlate cladogenesis and vicariance events during Cretaceous. Current biogeographic hypotheses suggest that living Pelomedusoides distribution and relationships could be the result of large-scale extinctions with extant taxa being relicts of a widespread group. The examination of relationships within Pelomedusoides allows the association of vicariance events of Gondwana fragmentation during the Cretaceous with the isolation of pelomedusoid lineages. We identified three vicariant events: the separation of northern Pelomedusoides and southern Chelidae (node of divergence of Chelidae); the isolation of Africa from Gondwana (node of divergence of Hamadachelys); and the separation of South America and India/Madagascar (node of divergence of Podocnemididnae and Erymnochelyinae). Extant Podocnemidinae (restricted to north South America) would derivate from a south South American source. Its ancestor would have had an autochthons development in South America, expanding its distribution northwards. The presence of Erymnochelyinae in Madagascar would be explained by the migration of a South American ancestor via Antarctica.

Several studies have associated the chytrid fungus Batrachochytrium dendrobatidis with worldwide anuran population declines. Recently, six species have been reported to be infected by chytridiomycosis in Brazil, presenting a wide range of distribution, of about 2,400 km over the Atlantic Forest. However, in a country such as Brazil, information about this disease is still beginning to accumulate. Based on morphological and histological data, we found evidence of B. dendrobatidis infection in 16 Brazilian anuran species, members of the families Cycloramphidae and Hylidae. We analyzed tadpoles lacking teeth that were collected from 1964 to 2005, to seek for chytridiomycosis. Our results extend the distribution of the fungus in Brazil ca. 630 km southward (straight-line distance), reaching the southernmost limits of the Atlantic rainforest. We also speculate about its distribution in the Cerrado and Pantanal.

Leptodactylus validus has an unusual distribution, inhabiting Trinidad, Tobago, and the Lesser Antilles, but not the mainland of South America. This distribution is inconsistent with other distribution patterns observed for these islands. Although slight variation in adult morphology has been observed among the different island populations of L. validus, call data suggest the presence of a single species. Calls of L. pallidirostris from Venezuela and Brazil suggested that this taxon might be conspecific with L. validus, Sequence data from the 12S and 16S mt rDNA genes indicate that L. validus represents a single species throughout its distribution and is conspecific with L. pallidirostris, Dispersal of L. validus from Trinidad and Tobago to the Lesser Antilles was likely mediated by human activities.

A detailed redescription of the larval morphology of the ceratophryid frog Chacophrys pierottii is presented with an account of the pattern of lateral-line organs and comments on larval biology. Variation in the nasal appendix, a unique feature of Chacophrys tadpoles, is described. Comparisons are made with larvae of two closely related genera, Ceratophrys and Lepidobatrachus. In contrast to members of these genera, which have highly modified carnivorous larvae, the larvae of Chacophrys pierottii resemble typical Type IV tadpoles. However, the larvae of all ceratophryid genera possess uninterrupted marginal papillae surrounding the oral disc.

Aspects of ecology are described for the Yucatán colubrid snake Conophis lineatus concolor, as inferred from examinations of museum specimens and a review of published literature records. Adult males of this distinctive subspecies are larger than females (> 890 mm versus < 760 mm SVL) and at the same body size males also have longer tails, although sexual dimorphism in other proportional features of morphology is negligible. Food habits are diverse; of 29 prey items identified to main taxonomic group, the most important in terms of relative composition (l_x) were lizards (0.394) and arthropods (0.391), followed by squamate eggs (0.061) and thereafter in equal measure by frogs, snakes, and mammals (0.044). More than 90% of the arthropods were engorged cattle ticks, Boophilus microplus, and several snakes had fed exclusively on this prey type. An ontogenetic increase was evident in the proportion of larger prey consumed, although samples were inadequate to allow an assessment of the relationship between prey size and the observed sexual difference in snake body size. Clutch size varied from 5-8, and females appear to have an extended reproductive cycle with oviposition timed to the wet season.

We describe a new species of the poorly known genus Calamodontophis from the state of Paraná, Southern Brazil. The new species is compared with C. paucidens and species of related genera. We provide comments on the generic relationships of Calamodontophis within the xenodontine radiation, as well as on the behavioral, feeding, and reproductive aspects of the biology of the group.

In many anuran species, vocalizations play an important role in the establishment of their social organization. From March 2004 to January 2006 calls of Aplastodiscus arildae and A. leucopygius were recorded in the Serra do Japi, Municipality of Jundiaí, State of São Paulo, Brazil. We identified three different calls for both studied species and their functions were determined analyzing the social context in which they were emitted. We measured the following call parameters: minimum and maximum frequency of the harmonics, dominant frequency, intensity of the calls, interval between calls, repetition rates, and duration of the calls. Advertisement call parameters of A. arildae and A. leucopygius agree with the data available in the literature. However, in the present study, new information on the advertisement call of A. leucopygius and its social implication and the description of territorial and courtship calls of A. arildae were obtained.