J. Celsa Señaris

High levels of diversity uncovered in a widespread nominal taxon: continental phylogeography of the Neotropical tree frog Dendropsophus minutus

Species distributed across vast continental areas and across major biomes provide unique model systems for studies of biotic diversification, yet also constitute daunting financial, logistic and political challenges for data collection across such regions. The tree frog Dendropsophus minutus (Anura: Hylidae) is a nominal species, continentally distributed in South America, that may represent a complex of multiple species, each with a more limited distribution. To understand the spatial pattern of molecular diversity throughout the range of this species complex, we obtained DNA sequence data from two mitochondrial genes, cytochrome oxidase I (COI) and the 16S rhibosomal gene (16S) for 407 samples of D. minutus and closely related species distributed across eleven countries, effectively comprising the entire range of the group. We performed phylogenetic and spatially explicit phylogeographic analyses to assess the genetic structure of lineages and infer ancestral areas. We found 43 statistically supported, deep mitochondrial lineages, several of which may represent currently unrecognized distinct species. One major clade, containing 25 divergent lineages, includes samples from the type locality of D. minutus. We defined that clade as the D. minutus complex. The remaining lineages together with the D. minutus complex constitute the D. minutus species group. Historical analyses support an Amazonian origin for the D. minutus species group with a subsequent dispersal to eastern Brazil where the D. minutus complex originated. According to our dataset, a total of eight mtDNA lineages have ranges >100,000 km2. One of them occupies an area of almost one million km2 encompassing multiple biomes. Our results, at a spatial scale and resolution unprecedented for a Neotropical vertebrate, confirm that widespread amphibian species occur in lowland South America, yet at the same time a large proportion of cryptic diversity still remains to be discovered.

Systematics of spiny-backed treefrogs (Hylidae: Osteocephalus): An Amazonian puzzle

Spiny‐backed tree frogs of the genus Osteocephalus are conspicuous components of the tropical wet forests of the Amazon and the Guiana Shield. Here, we revise the phylogenetic relationships of Osteocephalus and its sister group Tepuihyla, using up to 6134 bp of DNA sequences of nine mitochondrial and one nuclear gene for 338 specimens from eight countries and 218 localities, representing 89% of the 28 currently recognized nominal species. Our phylogenetic analyses reveal (i) the paraphyly of Osteocephalus with respect to Tepuihyla, (ii) the placement of ‘Hyla’ warreni as sister to Tepuihyla, (iii) the non‐monophyly of several currently recognized species within Osteocephalus and (iv) the presence of low (<1%) and overlapping genetic distances among phenotypically well‐characterized nominal species (e.g. O. taurinus and O. oophagus) for the 16S gene fragment used in amphibian DNA barcoding. We propose a new taxonomy, securing the monophyly of Osteocephalus and Tepuihyla by rearranging and redefining the content of both genera and also erect a new genus for the sister group of Osteocephalus. The colouration of newly metamorphosed individuals is proposed as a morphological synapomorphy for Osteocephalus. We recognize and define five monophyletic species groups within Osteocephalus, synonymize three species of Osteocephalus (O. germani, O. phasmatus and O. vilmae) and three species of Tepuihyla (T. celsae, T. galani and T. talbergae) and reallocate three species (Hyla helenae to Osteocephalus, O. exophthalmus to Tepuihyla and O. pearsoni to Dryaderces gen. n.). Furthermore, we flag nine putative new species (an increase to 138% of the current diversity). We conclude that species numbers are largely underestimated, with most hidden diversity centred on widespread and polymorphic nominal species. The evolutionary origin of breeding strategies within Osteocephalus is discussed in the light of this new phylogenetic hypothesis, and a novel type of amplexus (gular amplexus) is described.

Phylogenetic systematics of the genus Gonatodes (Squamata: Sphaerodactylidae) in the Guayana region, with description of a new species from Venezuela

The phylogenetic relationships and species boundaries of the diurnal geckos of the genus Gonatodes in the Guayana region are examined. Seven species of Gonatodes are recognized for the region, six of which are endemic to this region and form a monophyletic group together with G. hasemani from the southern part of the Amazon Basin. Two of the six species in this group are new to science, one of which is endemic to Venezuela and it is described here. Taxonomic accounts are provided for all the Venezuelan species of Gonatodes that are endemic to the Guayana region. The phylogenetic relationships of Gonatodes suggest that the diversity of this genus in the Guayana region has resulted mostly from in situ diversification rather than multiple colonization events by different lineages. The phylogenetic analyses also support that G. antillensis, the only nocturnal species in the genus, is indeed nested within Gonatodes, indicating re-evolution of some traits associated with nocturnal life. Finally, we comment on a recently proposed framework of temporal diversification in Gonatodes and suggest that we are still a long way from attaining a complete understanding about the systematics of this genus.

A NEW SPECIES OF GLASS FROG (ANURA: CENTROLENIDAE) FROM THE VENEZUELAN GUAYANA

A new species of Centrolene is named from the La Escalera Region in Estado Bolívar, Venezuela. The three species known from the Guianan Region of northeastern South America represent a single clade characterized by a white bib-like parietal peritoneum; this clade is referred to as the Centrolene gorzulai species group. Centrolenella auyantepuiana is placed in the synonymy of Centrolene gorzulai. Resumen Se describe una nueva especie de Centrolene de la Región de La Escalera, Estado Bolívar, Venezuela. Las tres especies conocidas de la Región Guayana al noreste de Sudamérica son reunidas en un nuevo grupo del género Centrolene. Centrolenella auyantepuiana es considerada sinónimo de Centrolene gorzulai.

Rediscovery of Atelopus cruciger (Anura: Bufonidae): current status in the Cordillera de La Costa, Venezuela

The genus Atelopus (Anura: Bufonidae) has suffered one of the most drastic declines recorded in the Neotropics. Nine of 10 Venezuelan species are categorized as Critically Endangered on the IUCN Red List. None of these species had been observed since the mid 1980s until recently, when an adult female of Atelopus mucubajiensis and several adults of A. cruciger were rediscovered. To assess the current distribution and status of A. cruciger we explored 15 locations where it was formerly known. Two populations were detected. Historical and current distri- bution maps were constructed based on these field explo- rations and data from museum collections. Using PCR assays we detected infection with Batrachochytrium den- drobatidis in one morbid and three live specimens. Our surveys suggest A. cruciger populations from lower alti- tudes on the northern slope of the Cordillera de La Costa are recovering, although the presence of B. dendrobatidis could jeopardize their long-term survival unless active conservation strategies are adopted.

Resurrection of Hyalinobatrachium orocostale and Notes on the Hyalinobatrachium orientale Species Complex (Anura: Centrolenidae)

Abstract Hyalinobatrachium orientale has a complex taxonomic history suggesting that more than one species could be under this name. In this review, we try to clarify the current taxonomic status of this species by means of morphological, bioacoustic, and mitochondrial DNA sequence comparisons of specimens from Tobago Island and the Venezuelan Cordillera de la Costa (Oriental Sector, Cordillera del Litoral and Cordillera del Interior). Our data support the resurrection of Hyalinobatrachium orocostale, restricted to the Cordillera del Interior. Additionally, specimens from Cordillera del Litoral and Oriental Sector do not form a monophyletic group; hence, we define as Hyalinobatrachium sp. the populations from Cordillera del Litoral and H. orientale sensu stricto the populations from the Oriental Sector. Preliminary bioacoustic and morphological analyses indicate that the populations from Tobago are conspecific with Hyalinobatrachium orientale sensu stricto.

A NEW SPECIES OF HYPSIBOAS (AMPHIBIA; ANURA; HYLIDAE) FROM THE VENEZUELAN GUAYANA, WITH NOTES ON HYPSIBOAS SIBLESZI (RIVERO 1972)

We describe a new species of Hypsiboas from the slopes and summit of Auyán-tepui in Canaima National Park, Bolívar State, Venezuela. The new species resembles H. sibleszi, but it differs from that species in having pale green dorsal coloration with numerous small chromatophores, dorsolateral white stripes that extend from the tip of snout to the groin when present, pale interorbital bar absent, a transparent yellow venter, yellow-colored digits and webbing, a more extensive webbing on hands and feet, a prepollical spine not protunding, very narrow nasals partially fused with sphenethmoid, a moderate-sized frontoparietal fontanelle, and an advertisement call consisting of three or four notes with a dominant frequency between 3010 and 3488 Hz. New data on the vocalization, osteology and distribution of H. sibleszi are provided.

A new species of Hyla (Anura: Hylidae) from the highlands of venezuelan guayana

Abstract A new species of Hyla is described from Cerro Jaua, 1600 m, Bolívar State, Venezuela. The external appearance of the new species closely resembles Hyla benitezi and Hyla lemai but differs from these species in having cream-colored digits and webbing (in live specimens), a golden iris, less foot webbing, no quadratojugal, and a characteristic advertisement call that consists of a rhythmically repeated note with a dominant frequency between 3260 and 3450 Hz.

CONTRIBUTION TO THE KNOWLEDGE OF THE TAXONOMY, DISTRIBUTION, AND NATURAL HISTORY OF LEPOSOMA HEXALEPIS (REPTILIA: GYMNOPHTHALMIDAE) IN VENEZUELA

We provide a redescription of Leposoma hexalepis based on 32 specimens, including males for the first time, and detailed data on the external morphology of the species, meristic characters, pattern of coloration in life and after preservation, and its geographic distribution. Resumen Se redescribe a Leposoma hexalepis basados en una serie de 32 ejemplares, donde se incluye por primera vez a los machos de esta especie. Se ofrecen datos detallados sobre su morfología externa, caracteres merísticos, patrones de coloración en vida y en preservativo y su distribución geográfica.

Amphibia, Anura, Centrolenidae, Centrolene daidaleum (Ruiz-Carranza and Lynch, 1991): first record for Venezuela, new altitudinal record, and distribution map

The glassfrog Centrolene daidaleum is considered endemic to the Cordillera Oriental of the Colombian Andes, and is known only from eight localities between 1,600 and 2,060 m, on the western slope of this mountain system. Herein we report the first record of this species from Venezuela based on specimens coming from the Sierra de Perija, Zulia state. The species’ altitudinal range is extended, and some ecological information is provided.