Mostrando postagens com marcador phylogeny and taxonomy. Mostrar todas as postagens
Mostrando postagens com marcador phylogeny and taxonomy. Mostrar todas as postagens

sábado, 18 de julho de 2015

O gênero Holochilus (Mammalia: Cricetidae) no Rio Grande do Sul: taxonomia e distribuição

MARQUES, R.V. 1988. O gênero Holochilus (Mammalia: Cricetidae) no Rio Grande do Sul: taxonomia e distribuição. Revista Brasileira de Zoologia 4(4):347-360.

Abstract. The genus Holochilus Brandt, 1835 is represented in Rio Grande do Sul, Southem Brazil, by two forms: H. brasiliensis vulpinus (Brants, 1827) e H. magnus Hershkovitz, 1955. They are myomorph rodents with semi-aquatic habits. Species of Holochilus range from Northern South America to Central Argentina. In this paper, I present an analysis ofstandard measurements of specimens collected in Southem Brazil and deposited in the collections of FZB, PUC and UFRGS and a distribution map with collecting localities.

sábado, 30 de maio de 2015

The taxonomic history of the south and central american akodont rodent genera: Thalpomys, Deltamys, Thaptomys, Hypsimys, Bolomys, Chroeomys, Abrothrix, Scotinomys, Akodon (Chalcomys and Akodon), Microxus, Podoxymys, Lenoxus, Oxymycterus, Notiomys, and Blarinomys

TATE, G.H.H. 1932. The taxonomic history of the south and central american akodont rodent genera: Thalpomys, Deltamys, Thaptomys, Hypsimys, Bolomys, Chroeomys, Abrothrix, Scotinomys, Akodon (Chalcomys and Akodon), Microxus, Podoxymys, Lenoxus, Oxymycterus, Notiomys, and Blarinomys. American Museum Novitates 582:1:32.

Abstract. In this paper, the sixth of my series, I have continued the treatment given in earlier papers. Since neither the several new akodont genera proposed by Thomas not his "groups" of the subgenus Akodon (sensu stricto) appear to be sharply defined, geographic arrangement of the species has been particularly difficult and may prove unsatisfactory. Though wishing to preserve, as much as possible, the arrangement of genera made by Thomas (1916), I have felt that certain changes were desirable: Zygodontomys has been treated in my fifth paper, and the akodont genera are rearranged so as to include Scotinomys and the new genera Deltamys and Hypsimys and to place Akodon (Akodon) next to Microxus.

sábado, 3 de janeiro de 2015

Genomic ancestry of the American puma

CULVER, M.; JOHNSON, W.E.; PECON-SLATTERY, J.; O'BRIEN, S.J. 2000. Genomic ancestry of the American puma (Puma concolor). The Journal of Heredity 91(3):186-197.

Abstract. Puma concolor, a large American cat species, occupies the most extensive range of any New World terrestrial mammal, spanning 110 degrees of latitude from the Canadian Yukon to the Straits of Magellan. Until the recent Holocene, pumas co-existed with a diverse array of carnivores including the American lion (Panthera atrox), the North American cheetah (Myracynonyx trumani), and the saber toothed tiger (Smilodon fatalis). Genomic DNA specimens from 135 pumas of specified geographic origin (261 contemporany and 54 museum specimens) were collected for molecular genetic and phylogenetic analyses of three mitochrondrial gene sequences (16S rRNA, ATPase-8, and NADH-5) plus composite microsatellite genotypes (10 feline loci). Six phylogeographic groupings or subspecies were resolved, and the entire North American population (186 individuals from 15 previously named subspecies) was genetically homogeneous in overall variation relative to central and South American populations. The marked uniformity of mtDNA and a reduction in microsatellite allele size expansion indicates that North American pumas derive from a recent (late Pleistocene circa 10,000 years ago) replacement and recolonization by a small number of founders who themselves originated from a centrum of puma genetic diversity in eastern South America 200,000-300,000 years ago. The recolonization of North American pumas was coincident with a massive late Pleistocene extinction event that eliminated 80% of large vertebrates in North America and may have extirpated pumas from that continent as well.

sábado, 15 de novembro de 2014

The phylogeny of Cetartiodactyla: the importance of dense taxon sampling, missing data, and the remarkable promise of cytochrome b to provide realiable species-level phylogenies

AGNARSSON, I.; MAY-COLLADO, L.J. 2008. The phylogeny of Cetartiodactyla: the importance of dense taxon sampling, missing data, and the remarkable promise of cytochrome b to provide realiable species-level phylogenies. Molecular Phylogenetics and Evolution 48:964-985.

Abstract. We perform Bayesian phylogenetic analyses on cytochrome b sequences from 264 of the 290 extant cetartiodactyl mammals (whales plus even-toed ungulates) and two recently extinct species, the "Mouse Goad" and the "Irish Elk". Previous primary analyses have included only a small portion of the species diversity within Cetartiodactyla, while a complete supertree analysis lacks resolution and branch lenghts limiting its utility for comparative studies. The benefits of using a single-gene approach include rapid phylogenetic estimates for a large number of species. However, single-gene phylogenies often differ dramatically from studies involving multiple datasets suggesting that they often are unrealiable. However, based on recovery of banchmark clades - clades supported in prior studies based on multiple independent datasets - and recovery of undisputed traditional taxonomic groups, Cytb performs extraordinarily well in resolving cetartiodactyl phylogeny when taxon sampling is dense. Missing data, however, (taxa with partial sequences) can compromise phylogenetic accuracy, suggesting a tradeoff between the benefits of adding taxa and introducing question marks. In the full data, a fez species with a short sequences appear misplaced, however, sequence lenght alone seems a poor predictor of this phenomenon as other taxa with equally short sequences were not conspicuously misplaced. Although we recommend awaiting a better supported phylogenetic hypotheses provided here represent the currently best available tool for comparative species-level studies within this group. Cytb has been sequenced for a large percentage of mammals and appears to be a reliable phylogenetic marker as long as taxon sampling is dense. Therefore, an opportunity exists now to reconstruct detailed phylogenies of most of the major mammalian clades to rapidly provide much needed tools for species-level comparative studies.

quarta-feira, 12 de novembro de 2014

Workshop em Sistemática Filogenética 2015

Estão abertas as inscrições para o Workshop em Sistemática Filogenética 2015, a ser realizado entre os dias 23 e 27 de fevereiro de 2015 na UNESP, campus de São Hosé do Rio Preto (SP). O idioma do Workshop é o Inglês, e as vagas são limitadas, até o dia 15 de dezembro de 2014. Os interessados podem obter mais informações pelo e-mail: workshopsistematica@gmail.com.

sábado, 4 de outubro de 2014

Napoleon Bonaparte and the fate of an Amazonian rat: new data on the taxonomy of Mesomys hispidus (Rodentia: Echimyidae)

ORLANDO, L.; MAUFFREY, J.-F.; CUISIN, J.; PATTON, J.L.; HÄNNI, C.; CATZEFLIS, F. 2003. Napoleon Bonaparte and the fate of an Amazonian rat: new data on the taxonomy of Mesomys hispidus (Rodentia: Echimyidae). Molecular Phylogenetics and Evolution 27:113-120.

Abstract. The spiny rat Mesomys hispidus is one of many South American rodents that lack adequate taxonomic definition. The few sampled populations of this broadly distribuuted trans-Amazonian arboreal rat have come from widely separated regions and are typically highly divergent. The holotype was described in 1817 by A.-G. Desmarest, after Napoleon's army brought it to Paris following the plunder of Lisbon in 1808; however, the locality of origin has remained unknown. Here we examine the taxonomic status of this species by direct comparison of 50 extant individuals with the holotype at the morphometric and genetic levels, the latter based on 331 bp of the mitochondrial cytochrome b gene retrieved from a small skin fragment of the holotype with ancient DNA technology. Extensive sequence divergence is present among samples of M. hispidus collected from throughout its range, from French Guiana across Amazonia to Bolivia and Peru, with at least seven mitochondrial clades recognized (average divergence of 7.7% Kimura 2-parameter distance). Sequence from the holotype is, however, only weakly divergent from those of recent samples from French Guiana. Moreover, the holotype clusters with greater that 99% posterior probability with samples from this part of Amazonia in a discriminant analysis based on 22 cranial and dental measurements. Thus, we suggest that the holotype was originally obtained in eastern Amazonia north of the Amazon River, most likely in the Brazilian state of Amapá. Despite the high level of sequence diversity and marked morphological differences in size across the range of M. hispidus, we continue to regard this assemblage as a single species until additional samples and analyses suggest otherwise.

sábado, 27 de setembro de 2014

The molecular phylogenetics of tuco-tucos (genus Ctenomys, Rodentia: Octodontidae) suggests an early burst of speciation

LESSA, E.P.; COOK, J.A. 1998. The molecular phylogenetics of tuco-tucos (genus Ctenomys, Rodentia: Octodontidae) suggests an early burst of speciation. Molecular Phylogenetics and Evolution 9(1):88-99.

Abstract. Variation in the nucleotide sequence of the entire mitochondrial cytochrome b gene (1140 bp) was examined for 27 individuals representing 13 species of South American rodents of the genera Ctenomys, Octodontomys, Tympanoctomys, and Spalacopus. Representatives of the family Echimyidae, Euryzygomatomys and Mesomys, were used as outgroups to test the monophyly of the Octodontinae and Ctenomyinae. Relationships among species of tuco-tucos (genus Ctenomys) were also exmined including representatives of the three described subgenera and the two sperm morphs. Reciprocal monophyly of the Octodontinae and Ctenomyinae is strongly supported. Several basal relationships among species of the genus Ctenomys are poorly resolved, suggesting the possibility of a hard polytomy due to a rapid and potentially simultaneous radiation early in the history of the genus. In other cases, clades within the Ctenomyinae previously identified on the basis of allozymes, chromosomes, parasites, or skull morphology were supported. Calibrations based on the fossil record suggest that the mitochondrial cytochrome b of these caviomorphs has evolved at a rapid rate, comparable to those proposed for Mus-Rattus, and three to four times higher than ungulate rates.

sábado, 16 de agosto de 2014

Cariotipo de Peromyscus grandis (Rodentia: Cricetidae)

ORDÓÑEZ-GARZA, N.; SWIER, V.J.; HANSON, J.D.; SOTERO-CAIO, C.G.; BRADLEY, R.D. 2013. Cariotipo de Peromyscus grandis (Rodentia: Cricetidae). Therya 4(3):575-580. doi: 10.12933/therya-13-122

Abstract. Peromyscus grandis is a rodent whose distribution is restricted to the mountain ranges of central Guatemala. This note represents the first report of karyotypic data for this species. The karyotype (fundamental number = 58) closely resembles karyotypes of other species of Peromyscus.

sábado, 12 de julho de 2014

Impacts of the Cretaceous terrestrial revolution and KPg extinction on mammal diversification

MEREDITH, R.W.; JANEčKA, J.E.; GATESY, J.; RYDER, O.A.; FISCHER, C.A.; TEELING, E.C.; GOODBLA, A.; EIZIRIK, E.; SIMÃO, T.L.L.; STADLER, T.; RABOSKY, D.L.; HONEYCUTT, R.L.; John J. FLYNN, J.J.; INGRAM, C.M.; STEINER, C.; WILLIAMS, T.L.; ROBINSON, T.J.; BURK-HERRICK, A.; WESTERMAN, M.; AYOUB, N.A.; SPRINGER, M.S.; William J. MURPHY, W.J. 2011. Impacts of the Cretaceous terrestrial revolution and KPg extinction on mammal diversification. Science 28(334):521-524.

Abstract. Previous analyses of relations, divergence times, and diversification patterns among extant mammalian families have relied on supertree methods and local molecular clocks. We constructed a molecular supermatrix for mammalian families and analyzed these data with likelihood-based methods and relaxed molecular clocks. Phylogenetic analyses resulted in a robust phylogeny with better resolution than phylogenies from supertree methods. Relaxed clock analyses support the long-fuse model of diversification and highlight the importance of including multiple fossil calibrations that are spread across the tree. Molecular time trees and diversification analyses suggest important roles for the Cretaceous Terrestrial Revolution and Cretaceous-Paleogene (KPg) mass extinction in opening up ecospace that promoted interordinal and intraordinal diversification, respectively. By contrast, diversification analyses provide no support for the hypothesis concerning the delayed rise of present-day mammals during the Eocene Period.

sábado, 21 de junho de 2014

Revision of the systematic status of Patagonian and Pampean gray foxes (Canidae: Lycalopex griseus and L. gymnocercus) using 3D geometric morphometrics

PREVOSTI, F.J.; SEGURA, V.; CASSINI, G.; MARTIN, G.M. 2013. Revision of the systematic status of Patagonian and Pampean gray foxes (Canidae: Lycalopex griseus and L. gymnocercus) using 3D geometric morphometrics. Mastozoología Neotropical 20(2):289-300.

Abstract. Argentinean “zorros de campo” are currently included in two species: Lycalopex griseus and L. gymnocercus. Lycalopex gymnocercus lives in northern Patagonia and in most of central and northern Argentina. Lycalopex griseus is smaller and lives in Patagonia and throughout western Argentina. A previous traditional morphometric study using cranio-dental measurements considered both forms to be the same species, showing clinal reduction in size from northeastern to southwestern Argentina. Here we tested the synonymy of these foxes and the existence of clinal variation using a large sample and geometric morphometric methods. Our results rejected the separation of these foxes in two different species and confirmed, based on cranium and mandible size and shape that they belong to the same species. Also, we show there is a clinal variation in size that has an allometric component in cranial and mandibular shape, which accounts for the differences between these foxes.

sábado, 10 de maio de 2014

Late Pleistocene (Rancholabrean) Glyptodont and Pampathere (Xenarthra, Cingulata) from Sonora, Mexico

MEAD, J.I.; SWIFT, S.L.; WHITE, R.S. MCDONALD, H.G.; BAEZ, A. 2007. Late Pleistocene (Rancholabrean) Glyptodont and Pampathere (Xenarthra, Cingulata) from Sonora, Mexico. Revista Mexicana de Ciências Geológicas 24(3):439-449.

Abstract. The fossil-rich deposits of Térapa (east-central Sonora) contain more than 60 zoological taxa, many with tropical affinities such as Crocodylus (crocodylian), Hydrochaeris (capybara), and many birds. The deposits also contain the dermal ossicles (osteoderms) of two extinct xenarthrans, a glyptodont (Glyptotherium cylindricum) and a pampathere (giant armadillo; Pampatherium cf. mexicanum). Glyptodont remains are also known from other less-well studied localities in Sonora. The faunas from these localities also contain the genus Bison, which indicates that the deposits are of the Rancholabrean Land Mammal Age, late Pleistocene. The presence of Pampatherium at Térapa and the presence of Glyptotherium at Térapa and the Río Mayo/Río Yaqui sites represent the first published accounts of these species from Sonora, and greatly extends their known geographical distribution during the Rancholabrean by about 1,100 km into northwestern Mexico.

sábado, 1 de março de 2014

Variatión geográfica del zorro Lycalopex culpaeus (Mammalia, Canidae) en Chile: implicaciones taxonómicas

GUZMÁN, J.A.; D'ELÍA, G.; ORTIZ, J.C. 2009. Variatión geográfica del zorro Lycalopex culpaeus (Mammalia, Canidae) en Chile: implicaciones taxonómicas. Revista de Biología Tropical 57(1-2):421-432.

Abstract. Geographic variation of the fox Lycalopex culpaeus (Mammalia, Canidae) in Chile: taxonomic implications. We studied the geographic variation of skulls of Lycalopex culpaeus using qualitative and quantative analyses. The sampling area covered Chile, from its northern portion, to Tierra del Fuego and the neighbouring Hoste Island, as well as part of Argentina. Five subespecies are currently recognized from this large area. We found two morphotypes that are segregated geographically. Both groups mostly differ by morphometric attributes, followed by qualitative features. Specimens from northern Chile (Tarapacá and Antofagasta) have small skulls, short rostrum, a liriform sagital zone, and lack the interparietal crest. The second group is formed by specimens from north-western and central Argentina, central-south Chile, Patagonia, and the austral islands of Tierra del Fuego and Hoste. This group presents a strong sagital crest, large rostrum, and a large skull. Our results agree with observed patterns of mitochondrial DNA variation. We propose to retain the name L. c. andinus for the populations of northern Chile and to synonymize L. c. magellanicus, L. c. lycoides, and L. c. smithersi under L. c. culpaeus.

sábado, 25 de janeiro de 2014

Systematics of Oxymycterus with description of a new species from Uruguay


Abstract. The taxonomic status of the genus Oxymycterus in Uruguay is assessed through morphologic, morphometric, and molecular comparisons with other species in the genus. Our analyses uncover the existence of a previously undescribed species, described herein, and restrict O. nasutus to SE Uruguay and SE Brazil. Uruguayan species are morphologically similar but differ substantially in sequences of the mitochondrial cytochrome-b gen. In contrast, O. rufus was found to be morphologically distinct from O. nasutus and the new species but genetically similar to the new species. Phylogenetic analyses lack resolution ar the base of the genus suggest well-supported relationships between O. amazonicus and O. delator, O. quaestor and O. judex, and O. rufus and the new species.

sábado, 18 de janeiro de 2014

A review of the boliviensis group of Akodon (Muridae:Sigmodontinae), with emphasis on Peru and Bolivia


Abstract. We recognize the Akodon boliviensis group as an informal assemblage of species including Akodon boliviensis (western Bolivia and Puno Department, Peru), Akodon puer (subspecies caenosus in northwestern Argentina and southern Bolivia, puer in central Bolivia, and lutescens in Puno Department, Peru and La Paz Department, Bolivia), Akodon subfuscus (subspecies subfuscus in southeastern Peru and La Paz Department, Bolivia; also a new subspecies from southeastern Peru), and Akodon n. sp. (central Peru). We further suggest that Akodon spegazzinii (subspecies spegazzinii and tucumanensis) from northern Argentina may be a member of this group. Akodon pacificus os shown to be a synonym of A. boliviensis. The bolivisneis group is diagnosed by a combination of characters including small size, delicate cranium, narrow and straight-sided mesopterygoid fossa, hourglass-shaped interorbital region, and dull brown fur without contrastingly colored areas.
Descriptions of included species and subspecies are provided. Traditional cranial, dental, and external characters are used in combination with electrophoresis and anatomical features of the soft palates, male reproductive tracts, and hind feet to recognize and diagnose species. Treatment of age-related variation is particularly important to distinguish these species; we document qualitative and quantitative changes in cranial morphology with age (toothwear class) and use regression to allow comparison of individuals of different ages.

We tentatively propose that subfuscus, puer, and the new species form a clade with bolivisneis as its sister group. This hypothesis cannot be subjected to formal test, however, until the condition of relevant characters in potential outgroups is better understood.

sábado, 14 de dezembro de 2013

Karyology of the Atlantic forest rodent Juliomys (Cricetidae): a new karyotype from southern Brazil

PARESQUE, R.; CHRISTOFF, A.U.; FAGUNDES, V. 2009. Karyology of the Atlantic forest rodent Juliomys (Cricetidae): a new karyotype from southern Brazil. Genetics and Molecular Biology 32:301-305.

Abstract. Juliomys is a small rodent from the family Cricetidae which inhabits the Atlantic forest and forests from Argentina to eastern Brazil. The three species recognized so far have different karyotypes. In this paper, we describe a new karyotype with 2n = 32, FN = 48 found in Juliomys specimens from a high-altitude area in the Atlantic forest of southern Brazil. The karyotype was analyzed after G- and C-banding and silver staining of the nucleolus organizer regions (Ag-NOR) and its G-banding patterns were compared with those of the newly described species Juliomys ossitenuis (2n = 20, FN = 36). The 2n = 32 karyomorph presented peculiar features and was very different from those of the other species of the genus: J. pictipes (2n = 36, FN = 34), J. rimofrons (2n = 20, FN = 34) and J. ossitenuis (2n = 20, FN = 36). Differences were mostly due to centric and tandem fusions, pericentric inversion and loss of hetero-chromatin. The karyotype represents a powerful tool to differentiate Juliomys species and our data suggest that the karyotype described herein belongs to a new species.

sábado, 23 de novembro de 2013

An introduction to Marmosops (Marsupialia: Didelphidae), with the description of a new species from Bolivia and notes on the taxonomy and distribution of other bolivian forms

VOOS, R.S.; TARIFA, T.; YENSEN, E. 2004. An introduction to Marmosops (Marsupialia: Didelphidae), with the description of a new species from Bolivia and notes on the taxonomy and distribution of other bolivian forms. American Museum Novitates 3466:1-40.

Abstract. In order to facilitate much-needed revisionary research on Marmosops, we summarize the currently accepted species-level taxonomy, provide full bibliographic citations for original descriptions of all 36 included nominal taxa, map their type localities, and list their type material (if known). We rediagnose the genus Marmosops, compare it with three other didelphid genera to which misidentified specimens of Marmosops have often been referred, and review the phylogenetic evidence that Marmosops is monophyletic. After describing a new species from the eastern-slope montane forest of Bolivia, we review the taxonomy of other Bolivian congeners based on morphological characters and published cytochrome-b gene sequences. Among our taxonomic results, we synonymize albiventris Tate (1931), dorothea Thomas (1911), and yungasensis Tate (1931) with M. noctivagus (Tschudi, 1845). By contrast, M. ocellatus (Tate, 1931), currently considered a synonym of dorothea, appears to be a valid species. Whereas published range maps of Bolivian species of Marmosops are demonstrably based on misidentified material and show little correspondence with known environmental factors, locality records based on specimens examined for this report make much more eco-geographic sense.

sábado, 2 de novembro de 2013

The historical bridge between the Amazon and the Atlantic Forest of Brazil: a study of molecular phylogeography with small mammals

COSTA, L.P. 2003. The historical bridge between the Amazon and the Atlantic Forest of Brazil: a study of molecular phylogeography with small mammals. Journal of Biogeography 30:71-86.

Abstract.
Aim. To examine how the genetic diversity of selected taxa of forest-dwelling small mammals is distributed between and within the major rain forest domains of Amazonia and Atlantic Forest and the intervening interior forests of Brazil, as inferred by the relationships between gene genealogies and geography. I also addressed the historical importance of the central Brazilian forests in connecting Amazon and Atlantic Forest populations of rodents and marsupials.
Methods. I evaluated variation in the mitochondrial cytochrome b gene to estimate the levels of sequence divergence between those taxa occurring throughout the Amazon, Atlantic Forest, and forests in the Cerrado and Caatinga regions. I inferred the hierarchical relationships between haplotypes, populations and formal taxa using the cladistic approach of maximum parsimony. I compared areas and the clades identified by superimposing cladograms on the geographical distribution of samples. The degree of concordance both in phylogeny and the depth of the nodes in these phylogenies, in addition to patterns of geographical distribution of clades, permitted me to make inferences on how, when and where the taxa differentiated.
Results. Sequence similarity is often greater between samples from the Atlantic Forest and either Amazon or central Brazilian forests than it is within each of the two rain forest domains. The Atlantic Forest clades are either not reciprocally monophyletic or are the sister group to all the other clades. There is some indication of northern and southern components in the Atlantic Forest. Given the geographical distribution of clades and the relatively deep levels of divergence, the central Brazilian area does not behave as a separate region but is complementary to either Amazon or Atlantic Forest. Patterns of area relationships differ across taxa, suggesting that different processes and ⁄or historic events affected the diversification within each lineage.
Main conclusions. The Amazon and the Atlantic forests are not exclusive in terms of their small mammal faunas; both overlap broadly with taxa occurring in gallery forests and dry forests in central Brazil. Central Brazilian forests are an integral part of the evolutionary scenario of lowland small mammals, playing an important role as present and past habitats for rain forest species. Therefore, representatives from this area should always be included in analyses of the evolutionary history of lowland rain forest faunas. The incongruence of branching patterns among areas is in agreement with recent results presented for Neotropical passerine birds and indicates that a single hypothesis of Neotropical area relationships is unlikely. These findings reinforce the idea that speciation in the Neotropics will not be explained by any single model of vicariance or climatic changes.

sábado, 10 de agosto de 2013

The pampas cat group (genus Lynchailurus Severtzov, 1858) (Carnivora: Felidae), a systematic and biogeographic review

GARCIA-PEREA, R. 1994. The pampas cat group (genus Lynchailurus Severtzov, 1858) (Carnivora: Felidae), a systematic and biogeographic review. American Museum Novitates 3096:1-36.

Abstract. A systematic study of 86 specimens of South American cats formerly known as Felis colocolo reveals three species, in addition to a new subspecies described herein. The three species are grouped in the genus Lynchailurus on the basis of shared character states. Lynchailurus pajeros occurs on high-elevation steppes from Ecuador to Bolivia and Argentina (eastern slope of the Andes), and farther south in Argentina into lowland steppe, shrubland, and dry forest habitats. Its southern limit is Patagonia (Argentinean and Chilean). Lynchailurus braccatus is found in Brazil, Paraguay, and Uruguay, where it occupies humid and warmer grassland and forested areas, at moderate elevations. Lynchailurus colocolo occurs in subtropical forests at middle elevations in central Chile, and in high-elevation steppes in northern Chile on the western slope of the Andes. The latter species may be endangered, because its distribution is limited. Assigned subspecies are as follows: L. pajeros budini and L. p. crespoi, in northwestern Argentina; L. p. crucinus, in southern Argentina and Chile; L. p. garleppi, in Peru; L. p. pajeros, in central Argentina; L. p. steinbachi, in Bolivia; L. p. thomasi, from Ecuador; L. braccatus braccatus, in southwestern Brazil and Paraguay; L. b. munoai, in Uruguay and southern Brazil; L. colocolo colocolo, in central Chile; and L. c. wolffsohni (new subspecies), in northern Chile.

sábado, 24 de novembro de 2012

Rediscovery and redescription of Marmosops handleyi (Pine, 1981) (Didelphimorphia: Didelphidae), the least known Andean slender mouse opossum

DÍAZ-N., J.; GÓMEZ-LAVERDE, M.; SÁNCHEZ-GIRALDO, C. 2011. Rediscovery and redescription of Marmosops handleyi (Pine, 1981) (Didelphimorphia: Didelphidae), the least known Andean slender mouse opossum. Mastozoología Neotropical 18(1):45-61.

Abstract. Marmosops handleyi was briefly described in 1981 based on two specimens collected in 1950 in the northern Andes of Colombia. Until now there have been no additional reported records for this species, and knowledge about its taxonomy, ecology, natural history and evolutionary relationships is deficient. Aiming to assess its current distribution, we searched for this species at four localities in the northern part of the Colombian Cordillera Central, where we collected the new material on which this report is based. Morphological comparisons with a sympatric congeneric species herein identified as M. caucae, revealed new external and craniodental characters that we use to redescribe M. handleyi. Our phylogenetic analysis groups M. handleyi as the sister taxon of a clade of small-bodied forms (M. parvidens +  M. pinheiroi), and a basal polytomy includes M. caucae (a Colombian taxon currently synonymized with M. impavidus) and other large-bodied forms. Finally, a reassessment of M. handleyi’s current conservation status suggests that the species should be transferred from Critically Endangered (CR) to Endangered (EN) IUCN category based on our discovery of additional extant populations.