The Peruvian sphaerodactyl gecko, Pseudogonatodes barbouri, is among the smallest reptile species in South America. Morphological information about this species, or even the genus, is limited. In this study, we produced a bone-by-bone description from the skull and atlantoaxial complex to contribute new phenotypic information about this poorly known lizard. To achieve this objective, we employed a divide-and-conquer approach in which each author digitally isolated one or two bones from the skull and produced a written description of these elements, thereby reducing 3D imaging processing and description to a fraction of time. In addition to a reduced phalanx in the fourth toe of both the hand and foot, the genus is characterized by having nasal bones with a broad lateral wing, an ectopterygoid that clasps the pterygoid, and an anterior shifting of the paroccipital process and as consequence the position of the quadrate, and squamosal not participating in the quadrate suspension. There are also modifications in fenestration and foramina and a trend towards synostosis of the jaw bones (e.g., coronoid splenial, compound bone surangular). Pseudogonatodes bears four long processes on the intercentrum of the axis; which is a character of New World sphaerodactyls.

The easternmost part of Amazonia, east of the Tocantins River, in Brazil, is also known as the Belém Area of Endemism (BAE) and falls mostly within the Amazonian “arc of deforestation” with the highest rate of deforestation in the region. Even though only one reptile species may be strictly endemic to the BAE, according to present knowledge, recognition of this area is useful for conservation purposes. Herein, we present a revision of current knowledge on the diversity and distribution of Squamata in the BAE in order to support conservation strategies and detect the main sampling gaps. We searched the literature and databases of several herpetological collections to compose the list of species for the area. For each species, we recorded distribution, habitat, and microhabitat. We present species accumulation curves for the whole area and for the two municipalities with largest samples, and prepared maps with species richness per municipality, current vegetation coverage, and conservation units present in the region. Additionally, we compare the number of known forest species of Squamata with the proportion of current forest cover for the best-sampled municipalities to test if there is a relationship between the conservation state of the area and the number of species. Our sampling reports 23,598 records of 147 species, including 7 amphisbaenians, 39 lizards, and 101 snakes. Sixty species (40.8%) are restricted to Amazonia, 12 (8.2%) are shared only with the Cerrado and 19 (12.9%) only with the Atlantic Forest, 1 (0.7%) is introduced, and the remaining 55 (37.4%) are shared with other biomes. Amphisbaena anomala and Stenocercus dumerilii are mostly associated with the BAE, and Atractus hoogmoedi is only known from its type locality and might represent a BAE endemic. Two species are threatened at the national level (Brazilian Red List) and five at the state level (Pará Red List). The largest samples and species richness are from the municipalities of Belém and Viseu; 9% of the municipalities have > 50 species, 32.4% have 1–10 species, and 38% remain unsampled. For 38 of the 50 municipalities with < 10% of forest cover, we have virtually no information on forest-dwelling species. Despite its high rate of deforestation, our knowledge of the herpetofauna of the BAE is based on a few limited areas; this fact hinders analyses of correlation with environmental factors and more appropriate definitions of conservation strategies. The largest tracks of forest remnants are mostly in indigenous lands, so it is important to develop strategies for studying these areas. The historically dynamic nature of the interchange between Amazonia and Cerrado biomes in the BAE might explain the tolerance of the species presented here to disturbed and secondary forests. Nonetheless, the increasing expansion of pastures, monocultures and urban areas in the area represent real and alarming threat.

Limited knowledge about species diversity restricts inferences about biogeography and macroecology in Amazonia, where biodiversity documentation has become particularly pressing due to anthropogenic impacts. An emblematic example of poorly known Amazonian amphibian diversity is that of Allobates nurse frogs, in which species boundaries and ranges are unclear. Based on genetic, morphological and call data from samples collected in 14 poorly known sites in Brazil, we identify and describe a new, broadly distributed western Amazonian nurse frog. In the light of the genetic data, combined with examination of more than 400 museum specimens, we also assess the distribution and levels of phenotypic variation in poorly known species from Amazonian lowlands, namely A. flaviventris, A. gasconi, A. subfolionidificans, and A. trilineatus. Lastly, our morphological examinations point to inconsistencies and heterospecific samples in the type series of A. fuscellus, A. gasconi, and A. vanzolinius, as revealed by large variation in key traits. By improving knowledge about species ranges and identifications, we hope that this study will support biodiversity inventories and stimulate further investigations of understudied western Amazonian nurse frogs.

Gladiator Frogs (Boana) is a Neotropical group comprised of 92 species sorted into seven species groups. Herein, we present a phylogeny of the Boana semilineata species group, including all valid nominal species currently or suspected to be assigned to it— many sequenced for the first time. Parsimony and maximum likelihood analyses of two genes (16S and COI) did not support the monophyly of the B. semilineata group as currently defined. To remedy this, B. secedens, currently assigned to the B. puchella species group, is transferred to the B. semilineata group. On the other hand, our analyses corroborate the inclusion of B. hutchinsi, B. pombali and B. wavrini in the B. semilineata group. The reinterpretation of the morphology of the lower palpebral membrane in B. pombali (previously described as absent, but actually present) corroborates that the reticulated membrane is a synapomorphy of this species group (albeit homoplastic—present in a few species not assigned to this group). A recent paper suggested (based on the analyses of 16S alone) that at least six unnamed taxa (candidate species) are hidden behind the names B. geographica and B. semilineata. Our analyses resulted in the discovery of additional unnamed lineages, one of which is described and named herein. This new species is diagnosed, among other characters, by having the flanks, anterior and posterior surfaces of thigh with dark brown or blackish stripes, and by the presence of a prepollex forming a projecting spine.

We describe a new species of Boana endemic to the Araguaia-Tocantins Basin in the center of the Brazilian Cerrado that was previously confused with species of the B. pulchella group. The new species is tentatively included in the B. albopunctata group on the basis of morphological and bioacoustics traits. The new species is characterized by a rounded head in dorsal view, dorsal color pattern consisting of three longitudinal beige stripes separated by two dark-brown stripes, posterior surfaces of thighs purple with dark-brown spots, and absence of a calcar appendage. Males have a pulsed advertisement call, with the end of the first note possessing an uncountable number of pulses. The new species differs from species of the B. pulchella group by the presence of a slip of the m. depressor mandibulae of scapular origin, presence of anterolateral processes of the hyoid, and curved dentigerous processes of vomers.

Understanding species distribution patterns is a central aim in ecology. Traditionally, the study of such patterns emphasizes the ecological traits of the organisms that allow them to interact with other species and with the environment. The perception that ecological differences may reflect the evolutionary history of a species has also highlighted the importance of considering phylogeny in studies of communities at different spatial scales. Based on this perspective, our goal was to investigate phylogenetic and ecological patterns in a community of anurans in a restinga (sandy coastal plain) environment on the northern coast of the state of Bahia, Brazil. First, we tested whether two ecomorphological traits of the studied species presented phylogenetic signal. Then, we analyzed the phylogenetic and ecological relationships of the anuran species that coexisted in the same spatial unit using the net relatedness index (NRI) and nearest related-taxon index (NTI). The results indicated that ecomorphological traits were conserved in the evolutionary history of the studied species. Furthermore, the anuran community was not phylogenetically structured, but there was a trend toward phylogenetic and ecological overdispersion, with an emphasis on the latter. This result suggests that the stochastic (related to dispersion of individuals) and deterministic processes (as interactions between species and between species and the environment) are likely acting together and affecting the investigated community at the local scale. The observed patterns could be explained by (i) the phylogenetic and ecological singularity of Pristimantis paulodutrai, a dominant species in the community, and (ii) high environmental diversity, which might have diversified the environment and increased the co-occurrence of many ecological traits related to habitat use by species, regardless of whether these differences were reflected in the phylogenetic structure of the community. Better insights will be achieved by combining phylogenetic, ecological, and environmental data to clarify the processes that structure anuran communities at different spatial scales.

Male-biased sexual size dimorphism (SSD), or a lack of SSD, in amphibians may be related to the territoriality. Male-biased SSD is quite abundant among the species of the Neotropical hylid genus Bokermannohyla. However, direct observations of territorial behaviour such as combat, suggestive of the presence of a male-biased SSD, are rare. We evaluated SSD in B. martinsi and provided a field record of a male–male combat event. We found males to have significantly wider forearm and longer tibia than females. It appears that male forearm hypertrophy is related to territoriality, but we cannot reject the possibility that it is an adaptation to breeding in lotic habitats. Finally, we emphasize the importance of direct natural history observations for understanding patterns of SSD among anurans in particular and amphibians in general.