27 julio 2009

Noblella coloma sp. nov.

A new species of Noblella (Amphibia: Strabomantidae) from the western slopes of the Andes of Ecuador

Abstract.-- We describe a new species of Noblella from the western slope of the Ecuadorian Andes. The new taxon is distinguished from all other species in the genus by lacking dorsal marks (i.e., interobital bar, scapular and sacral chevrons) and by having a bright orange venter. The new species and Noblella heyeri are the only species of Noblella reported in the Pacific Andean versant. We provide an osteological description of the new species and a key for the species in Noblella.

Cita / Citation: Guayasamín, J.M., A. Terán-Valdez. (2009) A new species of Noblella (Amphibia: Strabomantidae) from the western slopes of the Andes of Ecuador. Zootaxa 2161: 47–59.

Mas información: www.mapress.com/zootaxa/2009/f/z02161p059f.pdf

New Taxonomy Centrolenidae

Phylogenetic systematics of Glassfrogs (Amphibia: Centrolenidae) and their sister taxon Allophryne ruthveni

Abstract.-- Based on a molecular phylogeny, a new phylogenetic taxonomy that is compatible with both the International Code of Zoological Nomenclature (ICZN) and the PhyloCode is proposed for Glassfrogs and their sister taxon, Allophryne ruthveni. The arrangement presented herein emphasizes the recognition of clades having (i) significant statistical support and congruence among phylogenetic estimation methods (i.e., parsimony, maximum likelihood, and Bayesian inference criteria), (ii) congruence among genetic markers, and (iii) morphological and/or behavioral distinctiveness. Also, when previously recognized groups are recovered as monophyletic or nearly monophyletic, we propose taxa that minimize the number of name changes required to make these groups monophyletic, preserving the names and contents of previous classifications (i.e., nomenclatural stability). The evolutionary proximity of Centrolenidae and Allophrynidae is recognized by combining these families into an unraked taxon, Allocentroleniae—a proposal that maintains the traditional names and species contents of Centrolenidae and Allophrynidae. We arrange centrolenid diversity in two subfamilies: Centroleninae and Hyalinobatrachinae. Within Centroleninae, the diagnosis and species content of the genera Centrolene, Cochranella, and Nymphargus are modified; Teratohyla is resurrected and modified, and Chimerella, Espadarana, Rulyrana, Sachatamia, and Vitreorana are proposed as new genera. The other subfamily, Hyalinobatrachinae, contains the new genus Celsiella and a modified Hyalinobatrachium that fully corresponds to the former fleischmanni Group. Additionally, the genus Ikakogi is described. Ikakogi could not be assigned with confidence to either subfamily and it is placed as incertae sedis in Centrolenidae. The data at hand suggest that Ikakogi tayrona is a lineage as old as the subfamilies Hyalinobatrachinae and Centroleninae. The revised taxonomy differs markedly from previous arrangements, which were based on phenetics and few morphological characters. Most of the genera defined herein are confined to distinct biogeographic regions, highlighting the importance of geography in the speciation of Glassfrogs. The principal limitation of this proposal is that it is based on an incomplete sampling of taxa (54% of the recognized Glassfrogs). Although diagnoses are based on phenotypic traits, there are several cases (16% of all species) in which the allocation of species is ambiguous because of morphological homoplasy and the lack of molecular data. Finally, in an attempt to facilitate species identification, comparison, and generic placement, we provide photographs for most (~ 96%) of the recognized centrolenid species.

Cita / Citation: Guayasamin, J. M., S. Castroviejo-Fisher, L. Trueb, J. Ayarzagüena, M. Rada, y C. Vilà. (2009) Phylogenetic systematics of glassfrogs (Amphibia: Centrolenidae) and their sister taxon Allophryne ruthveni. Zootaxa 2100:1-97.

Mas información: http://www.mapress.com/zootaxa/2009/f/zt02100p097.pdf
Phylogenetic relationships of glassfrogs (Centrolenidae) based on mitochondrial and nuclear genes

Abstract.-- 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..

Cita / Citation: Guayasamin, J. M., S. Castroviejo-Fisher, J. Ayarzagüena, L. Trueb y C. Vilà. (2008) Phylogenetic relationships of glassfrogs (Centrolenidae) based on mitochondrial and nuclear genes. Molecular Phylogenetics and Evolution 48:574-595.

Mas información: http://www.puce.edu.ec/zoologia/vertebrados/personal/colaboradores/jmguayasamin/index.html

Pristimantis andinognomus sp. nov.

A Minute New Ecuadorian Andean Frog (Anura: Strabomantidae, Pristimantis)

Abstract.-- We describe a new species of Pristimantis from a cloud forest at 2450–2800 m in the Cordillera Oriental in southern Ecuador (Zamora Chinchipe). The new species has a maximum snout–vent length of 17.9 mm (average SVL of 21 males = 12.3 mm ± 1.2, and of 19 females = 15.9 mm ± 1.3). This new species is the second smallest frog from Ecuador and smallest Pristimantis. Morphologically and phylogenetically, the new species is similar to P. caeruleonotus and P. colodactylus. It is distinguished from them and its congeners by its size, tuberculation, a distinct color pattern consisting of tan blotches on dorsum, spots on a brown venter, minute brown spots on anterior and posterior surfaces of the thighs, and other morphological features. Determination of small body size in frogs is discussed and meristic data of 40 minute frogs are compiled..

Cita / Citation: Lehr, E. & L. A. Coloma. (2008) A minute new Ecuadorian Andean frog (Anura: Strabomantidae, Pristimantis). Herpetologica 64(3): 354–367..

Mas información: http://www.puce.edu.ec/zoologia/vertebrados/personal/lacoloma/index.html

Cochranella mcdiarmidi sp. nov.

A New Species of Glassfrog (Anura: Centrolenidae) from the Foothill Andean Forests of Ecuador and Peru

Abstract.-- We describe a new species of glassfrog assigned to the genus Cochranella (Amphibia: Anura: Athesphatanura: Centrolenidae) from the Foothill Evergreen forests on the southeastern Andean slopes of Ecuador and northeastern Andean slopes of Peru. The new species is characterized by its moderate-sized body (25.4–26.9 mm in adult males), medium-sized eyes (eye diameter/third disc width = 1.4–1.9), distinctive coloration in life (olive green with light spots) and in preservative (grayish lavender with pale spots), dorsal skin covered with flat warts and low tubercles, parietal peritoneum mostly white (covered by iridophores), thick ulnar folds, and extensive hand and foot webbing. In addition, we provide the first record of Nymphargus posadae from Peru, found in sympatry with the new species at the Cordillera del Cóndor..

Cita / Citation: Cisneros-Heredia, D.F., P. J. Venegas, M. Rada & R. Schulte. 2008. A new species of Glassfrog (Anura, Centrolenidae) from the Foothill Andean forests of Ecuador and Peru. Herpetologica 64(3): 342-353..

Mas información: http://www.cisneros-heredia.org/public

Amazonian Amphibian Diversity

Amazonian Amphibian Diversity Is Primarily Derived from Late Miocene Andean Lineages

Abstract.-- The Neotropics contains half of remaining rainforests and Earth's largest reservoir of amphibian biodiversity. However, determinants of Neotropical biodiversity (i.e., vicariance, dispersals, extinctions, and radiations) earlier than the Quaternary are largely unstudied. Using a novel method of ancestral area reconstruction and relaxed Bayesian clock analyses, we reconstructed the biogeography of the poison frog clade (Dendrobatidae). We rejected an Amazonian center-of-origin in favor of a complex connectivity model expanding over the Neotropics. We inferred 14 dispersals into and 18 out of Amazonia to adjacent regions; the Andes were the major source of dispersals into Amazonia. We found three episodes of lineage dispersal with two interleaved periods of vicariant events between South and Central America. During the late Miocene, Amazonian, and Central American-Chocoan lineages significantly increased their diversity compared to the Andean and Guianan-Venezuelan-Brazilian Shield counterparts. Significant percentage of dendrobatid diversity in Amazonia and Chocó resulted from repeated immigrations, with radiations at <10.0 million years ago (MYA), rather than in situ diversification. In contrast, the Andes, Venezuelan Highlands, and Guiana Shield have undergone extended in situ diversification at near constant rate since the Oligocene. The effects of Miocene paleogeographic events on Neotropical diversification dynamics provided the framework under which Quaternary patterns of endemism evolved.

Taxonomic proposals: Some changes to Grant et al.’s taxonomy were suggested by this paper, including:

- The proposed split of Dendrobatidae into two families (i.e., Allobatidae and Dendrobatidae) was not followed and this paper returned Dendrobatidae to a single family.
- This paper restricted Colostethus to the group of C. latinasus and allies (species in Colostethus 1 clade). Colostethus sensu lato is applied to the aggregate of species found in Colostethus 1 and 2 clades in their phylogeny.
- This paper synonymized Adelphobates, Excidobates, Minyobates, Oophaga, and Ranitomeya in the genus Dendrobates.
- Allobates craspedoceps was found within Hyloxalus, so a new combination was proposed: Hyloxalus craspedoceps.
- Hyloxalus argyrogaster was found with Colostethus sensu lato, so its new combination is Colostethus argyrogaster.
- Allobates peruensis (closely allied to A. kingsburyi) is a valid name.

Cita / Citation: Santos, J.C., et al. (2009) Amazonian Amphibian Diversity Is Primarily Derived from Late Miocene Andean Lineages. PLoS Biol 7(3): e1000056. doi:10.1371/journal.pbio.1000056.

Mas información: http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.1000056

Enyalioides touzeti sp. nov.

A new species of Enyalioides (Iguanidae: Hoplocercinae) from southwestern Ecuador

Abstract.-- We describe a new species of Enyalioides from lowland cloud forests in southwestern Ecuador. This represents the third species in the genus known to occur west of the Andes in South America; the other two species are E. heterolepis and E. oshaughnessyi. Among other characters, the new species can be distinguished from other members in the genus by having small, keeled, paravertebrals; a series of skin folds on the lateral aspects of body and neck; size-homogeneous scales on body and limbs; distinct caudal segments; and an extensive dark patch on the gular region of adult males. Morphological similarity suggests that the new species, which we call E. touzeti, is closely related to E. oshaughnessyi.

Cita / Citation: Torres-Carvajal, O. et al. (2008) A new species of Enyalioides (Iguanidae: Hoplocercinae) from southwestern Ecuador. Pap. Avulsos Zool. (São Paulo) 48(20): 227-235 . Available from: <http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0031-10492008002000001&lng=en&nrm=iso>.

Mas información: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0031-10492008002000001&lng=en&nrm=iso