Juan M. Guayasamin

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.

Phylogenetic relationships of glassfrogs (Centrolenidae) based on mitochondrial and nuclear genes

Glassfrogs (family Centrolenidae) represent an exceptionally diverse group among Neotropical anurans, but their evolutionary relationships never have been assessed from a molecular perspective. Mitochondrial and nuclear markers were used to develop a novel hypothesis of centrolenid phylogeny. Ingroup sampling included 100 terminals, with 78 (53%) of the named species in the family, representing most of the phenotypic diversity described for the group. Thirty-five species representing taxa traditionally associated with glassfrogs were used as outgroups. Gene sampling consisted of complete or partial sequences of three mitochondrial (12S, 16S, ND1) and three nuclear markers (c-myc exon 2, RAG1, POMC) for a total of approximately 4362bp. Phylogenies were estimated using maximum parsimony, maximum likelihood, and Bayesian analyses for individual genes and combined datasets. The separate analysis of mitochondrial and nuclear datasets allowed us to clarify the relationships within glassfrogs; also, we corroborate the sister-group relationship between Allophryne ruthveni and glassfrogs. The new phylogeny differs significantly from all previous morphology-based hypotheses of relationships, and shows that hypotheses based on few traits are likely to misrepresent evolutionary history. Traits previously hypothesized as unambiguous synapomorphies are shown to be homoplastic, and all genera in the current taxonomy (Centrolene, Cochranella, Hyalinobatrachium, Nymphargus) are found to be poly- or paraphyletic. The new topology implies a South American origin of glassfrogs and reveals allopatric speciation as the most important speciation mechanism. The phylogeny profoundly affects the traditional interpretations of glassfrog taxonomy, character evolution, and biogeography-topics that now require more extensive evaluation in future studies.

A NEW SPECIES OF FROG OF THE ELEUTHERODACTYLUS LACRIMOSUS ASSEMBLAGE (LEPTODACTYLIDAE) FROM THE WESTERN AMAZON BASIN, WITH COMMENTS ON THE UTILITY OF CANOPY SURVEYS IN LOWLAND RAINFOREST

We describe a new species of Eleutherodactylus from the lowlands of the western Amazon Basin. The new species is referred to the Eleutherodactylus unistrigatus group, lacrimosus assemblage. It differs from other members of the group by having a dorsal olive-green coloration with an interorbital creamy yellow stripe that extends posterolaterally and reaches the level of the sacrum, and low ulnar and tarsal tubercles. The new species inhabits western Amazon tropical rainforests and has been found in arboreal bromeliads by day and on vegetation by night. We discuss the effect of lack of sampling in the forest canopy in our understanding of tropical amphibian communities. Based on work conducted at two localities in Ecuadorian Amazonia, we find that even limited sampling effort in the canopy can greatly improve efficiency of biological inventories.

A NEW SPECIES OF GLASS FROG (CENTROLENIDAE: COCHRANELLA) FROM THE LOWLANDS OF NORTHWESTERN ECUADOR, WITH COMMENTS ON THE COCHRANELLA GRANULOSA GROUP

We describe a new species of Cochranella from the Montañas de Mache in the Chocó Ecoregion of the lowlands of northwestern Ecuador. The new species is placed in the Cochranella granulosa group and can be distinguished from all other species of Cochranella by having: (1) white parietal and visceral peritonea; (2) a snout that is gradually inclined in lateral aspect; (3) conspicuous dermal folds, and large, white tubercles on ventrolateral edges of Finger IV, forearms, elbows, tarsi, Toe V, and heels; (4) fleshy, tuberculate, ∩-shaped cloacal fold; and (5) dorsum green with small yellow dots in life. The new species shares several characters with C. daidalea, C. resplendens, C. savagei and C. solitaria, including dermal folds with white tubercles on the arms and legs, snout gradually inclined in profile, and cloacal ornaments. Finally, we briefly discuss the characters that define the Cochranella granulosa group.

A Revision of Species Diversity in the Neotropical Genus Oreobates (Anura: Strabomantidae), with the Description of Three New Species from the Amazonian Slopes of the Andes

ABSTRACT We revisit species diversity within Oreobates (Anura: Strabomantidae) by combining molecular phylogenetic analyses of the 16S rRNA amphibian barcode fragment with the study of the external morphology of living and preserved specimens. Molecular and morphological evidence support the existence of 23 species within Oreobates, and three additional candidate species (Oreobates sp. [Ca JF809995], Oreobates sp. [Ca EU368903], Oreobates cruralis [Ca EU192295]). We describe and name three new species from the Andean humid montane forests of Departamento Cusco, southern Peru: O. amarakaeri New Species from Río Nusinuscato and Río Mabe, at elevations ranging from 670 to 1000 m in the Andean foothills; O. machiguenga, new species, from Río Kimbiri (1350 m), a small tributary of the Apurimac River, in the western versant of Cordillera Vilcabamba; and O. gemcare, new species, from the Kosñipata Valley at elevations ranging from 2400 to 2800 m. The three new species are readily distinguished from all other Oreobates by at least one qualitative morphological character. Three species are transferred to Oreobates from three genera of Strabomantidae: Hypodactylus lundbergi Pristimantis crepitans, and Phrynopus ayacucho (for which the advertisement call, coloration in life, and male characteristics are described for first time). Oreobates simmonsi is transferred to the genus Lynchius. Hylodes verrucosus is considered a junior synonym of Hylodes philippi. In addition, H. philippi is removed from the synonymy of O. quixensis and considered a nomem dubium within Hypodactylus. The inclusion of Phrynopus ayacucho in Oreobates extends the ecological range of the genus to the cold Andean puna. Oreobates is thus distributed from the Amazonian lowlands in southern Colombia to northern Argentina, reaching the Brazilian Atlantic dry forests in eastern Brazil, across an altitudinal range from ca. 100 to 3850 m.

A new cryptic species of glassfrog (Centrolenidae: Nymphargus) from Reserva Las Gralarias, Ecuador

We describe a new species of Nymphargus from Reserva Las Gralarias, in the montane forests of the Pacific versant ofthe Andes of Ecuador. The new species, Nymphargus lasgralarias sp. nov., is nearly morphologically identical to sym-patric Nymphargus griffithsi (Goin 1961), with the exception of the following characters: (i) a gold colored iris with nu-merous small spots and lighter reticulation, (ii) absence of dark dorsal spotting, and (iii) a significantly larger body size.Additionally, we describe the vocalizations for N. griffithsi and N. lasgralarias. The call of N. lasgralarias sp. nov. is eas-ily distinguished from N. griffithsi through the following temporal and spectral characteristics: (i) calls are emitted in series, (ii) waveform shape is always pulsed, (iii) significantly shorter call duration, and (iv) lower dominant frequency.

Molecular phylogeny and systematics of Neotropical toucanets in the genus Aulacorhynchus (Aves, Ramphastidae)

Bonaccorso, E., Guayasamin, J. M., Peterson, A. T. & Navarro‐Sigüenza, A. G. (2011). Molecular phylogeny and systematics of Neotropical toucanets in the genus Aulacorhynchus (Aves, Ramphastidae). —Zoologica Scripta, 40, 336–349.

On the Origin of Pantepui montane biotas: A Perspective Based on the Phylogeny of Aulacorhynchus toucanets

To understand the origin of Pantepui montane biotas, we studied the biogeography of toucanets in the genus Aulacorhynchus. These birds are ideal for analyzing historical relationships among Neotropical montane regions, given their geographic distribution from Mexico south to Bolivia, including northern Venezuela (Cordillera de la Costa), and the Pantepui. Analyses were based on molecular phylogenies using mitochondrial and nuclear DNA sequences. Topology tests were applied to compare alternative hypotheses that may explain the current distribution of Aulacorhynchus toucanets, in the context of previous hypotheses of the origin of Pantepui montane biotas. Biogeographic reconstructions in RASP and Lagrange were used to estimate the ancestral area of the genus, and an analysis in BEAST was used to estimate a time framework for its diversification. A sister relationship between the Pantepui and Andes+Cordillera de la Costa was significantly more likely than topologies indicating other hypothesis for the origin of Pantepui populations. The Andes was inferred as the ancestral area for Aulacorhynchus, and the group has diversified since the late Miocene. The biogeographic patterns found herein, in which the Andes are the source for biotas of other regions, are consistent with those found for flowerpiercers and tanagers, and do not support the hypothesis of the geologically old Pantepui as a source of Neotropical montain diversity. Based on the high potential for cryptic speciation and isolation of Pantepui populations, we consider that phylogenetic studies of additional taxa are important from a conservation perspective.

The territoriality, vocalizations and aggressive interactions of the red-spotted glassfrog, Nymphargus grandisonae, Cochran and Goin, 1970 (Anura: Centrolenidae)

In many frog species, males defend a territory through direct male-to-male interactions and/or aggressive calling behaviour. We describe the site fidelity, vocalizations, aggressive interactions, and male combat behaviour of the glassfrog Nymphargus grandisonae. We show high specificity of males’ calling and mating sites. We then describe the temporal and spectral differences for six types of vocalizations. We link these vocalizations to behavioural observations, describing their aggressive and reproductive contexts. Additionally, we show that combat is highly variable and includes three previously described and two unreported variations. We describe injuries resulting from combat and we report the first observation of a multiple night fight between the same two males. Our observations on site fidelity and aggression provide evidence for territoriality among males. Furthermore, our results suggest that combat behaviour in glassfrogs is more complex than previously hypothesized and that hypotheses on the evolution of combat behaviour need re-evaluation.

A NEW SPECIES OF ELEUTHERODACTYLUS (ANURA: LEPTODACTYLIDAE) FROM THE NORTHWESTERN LOWLANDS OF ECUADOR

A new species of Eleutherodactylus is described from the lowlands of northwestern Ecuador. The new species is a small frog (snout–vent length <23 mm) characterized by: expanded and spadate disc cover on some fingers (usually III and IV) and most toes (usually III–V); bifid palmar tubercle; and brown dorsum with dark brown W-shaped scapular mark. A detailed osteological description of the new species is provided. Some of the osteological characters include relatively large nasals, small sphenethmoid, eight procoelous presacral vertebrae, manus with six carpal elements, and pes with four tarsal elements. A small portion of the frontoparietal fontanelle is exposed between the frontoparietals. Although the new species is small, there is no loss of skull bones and phalangeal elements.