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The genus Dasyprocta Illiger, 1811 includes at least 13 species of medium-sized caviomorph rodents, widely distributed from Mexico to northern Argentina. Despite being abundant, largely diurnal, and easily identifiable by their external traits, the taxonomy of this genus remains poorly understood. In this work, we reviewed the taxonomy of Dasyprocta along the Andes and adjoining lowland areas of the western Neotropics, including samples from Mexico to northern Argentina, with emphasis on two species largely confounded—sometimes considered as synonyms—during the last century: D. punctata Gray, 1842 and D. variegata Tschudi, 1845. In the construction of our taxonomic hypotheses, we use a purely morphological approach, emphasizing qualitative and quantitative cranial features and external traits (color patterns). The results of multivariate statistical analysis and differences in color patterns support the species-level validity of D. punctata and D. variegata. Within this latter nominal form, we also include those populations from northern Argentina and eastern Bolivia that recently were referred to D. azarae. Based on our results, D. punctata (including bellula, callida, candelensis, chiapensis, chocoensis, colombiana, dariensis, isthmica, nuchalis, richmondi, underwoodi, yucatanica, and zuliae) extends from southern Mexico to Colombia, Ecuador, northernmost Peru, and western Venezuela, while D. variegata (including azarae, boliviae, and yungarum) is distributed from south–central Peru and southwestern Brazil to Bolivia and northwestern Argentina.

Information on dietary ecology plays a key role in a wide array of biological research and conservation decisions, but its availability is biased towards large and charismatic taxa, whereas small mammals are underrepresented. Of the scarce publications on the Neotropical sigmodontine rodents, most are concentrated in central-eastern Argentina and, up until now, no revision of the totality of these data has been made available. In this work, we performed a thorough review of the dietary information from over 50 publications on 22 species, finding omissions and errors propagated up to the present time. This resulted in a robust database, the proposal of a posteriori dietary categories, and a list of the species that have been neglected in feeding ecology research. In turn, we used that database to test whether the patterns which associate diet and morphology in medium-sized and large mammals could be replicated in these small rodents, despite their overall generalist habits and the restrictions characteristic to their size. We found that larger species tend towards a low-protein diet. Additionally, we identified some stomach types that are restricted to specific diets. These results are consistent with the observations for larger species and shed light on the biology of small mammals.

Muroid rodents are the most species-rich superfamily of rodents occurring in Argentina. Increased fieldwork with these mammals depicts the need of adequate keys to identify species on the base of external characters. In this contribution we provide three keys (one for families and subfamilies, and another two for Sigmodontinae and Muridae, respectively) for all known species of Cricetidae and Muridae distributed in Argentina (42 genera and 110 species). In addition to the dichotomous keys, and as a way to facilitate the identification, we include for each species a brief description of its distribution and the main habitats where it occurs.

The leaf-eared mouse, Phyllotis xanthopygus (Waterhouse 1837) is a widely distributed sigmodontine rodent in South America, with populations ranging from central Peru to southern Argentina and Chile. Previous morphological and molecular contributions have suggested that P. xanthopygus represents a species complex. In order to characterize and disclose this cryptic species complex, we perform a molecular genetic/phylogenetic analysis of representative samples across its geographical distribution. Phylogenetic analyses were based on sequences of cytochrome-b gene (801 base pairs; n = 114 specimens) and analysed by maximum likelihood and Bayesian approaches. We also employed a Bayesian implementation of the Poisson tree processes (bPTP) as a unilocus species delimitation method. Results from our phylogenetic analyses retrieve eight well-supported clades. Five of these clades belong to populations known as P. xanthopygus s.l., which were paraphyletic to the closely related species P. bonariensis, P. caprinus, and P. limatus, displaying strong genetic divergences (>8%). The (bPTP) analyses recovered ten species within P. xanthopygus s.l. plus related forms (i.e. P. bonariensis, P. caprinus, and P. limatus). Our results, coupled with chromosomal and morphological evidences, support the recognition of these clades at the species level and provide a new framework to characterize the leaf-eared mice complex. Our study highlights the importance of integrative approaches in disentangling the biodiversity of Neotropical rodents. Fil: Ojeda, Agustina Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Provincia de Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Universidad Nacional de Cuyo. Instituto Argentino de Investigaciones de las Zonas Áridas; Argentina Fil: Teta, Pablo Vicente. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina Fil: Jayat, Jorge Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; Argentina Fil: Lanzone, Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Posadas | Universidad Nacional de Misiones. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Posadas; Argentina Fil: Cornejo, Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Provincia de Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Universidad Nacional de Cuyo. Instituto Argentino de Investigaciones de las Zonas Áridas; Argentina Fil: Novillo, Agustina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Biodiversidad Neotropical. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Instituto de Biodiversidad Neotropical. Instituto de Biodiversidad Neotropical; Argentina Fil: Ojeda, Ricardo Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Provincia de Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Universidad Nacional de Cuyo. Instituto Argentino de Investigaciones de las Zonas Áridas; Argentina

O genero Abrocoma Waterhouse inclui oito especies viventes de ratos de tamanho medio, com pelos longos, macios e densos, orelhas grandes e caudas moderadas a curtas. Seis dessas especies estao incluidas informalmente no complexo de especies de A. cinerea (A. cinerea Thomas, A. budini Thomas, A. famatina Thomas, A. schistacea Thomas, A. vaccarum Thomas, and A. uspallata Braun and Mares). Os estudos de especimes alojados em colecoes biologicas e na reinterpretacao de evidencias morfologicas anteriores sugerem que a atual riqueza de especies reconhecida do genero possa ser superestimada. As abordagens morfologicas qualitativas e quantitativas sao consistentes com o reconhecimento de nao mais que dois morfotipos no complexo de especies de A. cinerea. Contudo, linhas adicionais de evidencia e abordagens sao necessarias para desembaracar a complexa taxonomia deste genero (por exemplo, analise filogenetica de sequencias de DNA). Ate entao, prefiro nao fazer alteracoes na classificacao atual da Abrocoma, especialmente levando em consideracao que qualquer alteracao taxonomica pode ter consequencias indesejaveis ​​na conservacao desses roedores.

The sigmodontine species name Geoxus lafkenche proposed by Teta and D’Elia (2016) is unavailable, given that the publication where it originally appears did not satisfy the requirements of the International Code of Zoological Nomenclature. In this note we establish the availability of the species name Geoxus lafkenche , by fulfilling those requirements.

The genus Microcavia includes five living species of caviomorph rodents endemic to southern South America. Microcavia jayat, the most recently described species, was recorded in only seven localities of Chaco Seco, in Santiago del Estero province, north-central Argentina. Based on cranial and mandibular remains, corresponding to 23 individuals recovered from owl pellets, we report the first record of this species in La Rioja province, Argentina. This new record implies a southwestern extension of approximately 390 km from the previously known nearest locality, and constitutes its first record in Chaco Serrano habitats within Chaco Seco ecoregion. El género Microcavia incluye cinco especies vivientes de roedores caviomorfos endémicos del sur de América del Sur. Microcavia jayat, la especie descrita más recientemente, se registró en sólo siete localidades del Chaco Seco de la provincia de Santiago del Estero, centro-norte de Argentina. Sobre la base de restos cráneo mandibulares, correspondientes a 23 individuos recuperados de egagrópilas de lechuza, informamos el primer registro de esta especie en la provincia de La Rioja. Este nuevo registro implica una extensión de aproximadamente 390 km hacia el suroeste de la localidad más cercana previamente conocida y constituye su primer registro en ambientes de Chaco Serrano de la ecorregión del Chaco Seco Fil: Bustamante, Erick Ivan. Universidad Nacional de Chilecito; Argentina Fil: Ortiz, Pablo Edmundo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Correlación Geológica. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Departamento de Geología. Cátedra Geología Estructural. Instituto Superior de Correlación Geológica; Argentina Fil: Teta, Pablo Vicente. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina Fil: Jayat, Jorge Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; Argentina

We reviewed the alpha taxonomy of the genus Ctenomys Blainville, 1826 in southernmost South America, with emphasis on those nominal forms previously associated with C. magellanicus Bennett, 1836. We integrate distinct lines of evidence, including variation of mtDNA sequences, and the assessment of quantitative and qualitative traits of skins and skulls; when available, karyotypic data was also considered. Phylogenetic analysis of molecular markers shows low levels of divergence among specimens from southern South American mainland and the island of Tierra del Fuego (ca. 0.4%). This evidence plus the results of the multivariate analysis of metric data suggest that the nominal forms C. colburni J. A. Allen, 1903, C. fueginus Philippi, 1880, C. osgoodi J. A. Allen, 1905, C. m. dicki Osgood, 1943, and C. m. obscurus Texera, 1975 are subjective junior synonyms of C. magellanicus. In addition, we reviewed the status of C. fodax Thomas, 1910, a nominal form that have been alternatively considered as a valid species or related to C. magellanicus by previous researchers. Based on quantitative and qualitative morphological traits, we preliminarily regard C. fodax at the species level while citing it for the first time to Chile.

Akodon oenos, a nominal form with type locality in northern Mendoza province, Argentina, has an intricate taxonomic history. Recently, it was considered a junior synonym of Akodon spegazzinii on the basis of morphological similarities of one individual captured in southern Mendoza with specimens belonging to the type series of A. oenos, plus the genetic similarity of that single specimen with representatives of A. spegazzinii. We compared specimens of the Akodon boliviensis species group recently captured in Mendoza with the type series of A. oenos and series of A. spegazzinii from northwestern Argentina. We conducted an analysis of molecular markers (cytochrome-b gene) and quantitative morphological studies (comparisons of skull measurements). Our results showed that: (1) all sequenced specimens of the A. boliviensis group from Mendoza form a monophyletic clade closely related to A. spegazzinii; (2) contrary to previous hypothesis, specimens of Akodon from Mendoza are morphologically distinctive in size and shape of the skull, from A. spegazzinii; and (3) within the A. boliviensis species group, specimens from Mendoza are distinctive. We argue that the synonymy of A. oenos under A. spegazzinii must await further studies, including molecular markers other than mitochondrial and samples of DNA sequences from topotypical specimens of A. oenos.

Sigmodontine rodents, with 86 genera and ~430 living species, constitute one of the most successful radiations of Neotropical mammals. In this contribution, we studied the distributional ranges of 108 sigmodontine species in Argentina. Our objectives were (i) to establish geographical patterns of species richness and endemism, and (ii) to evaluate the regional conservation status of these taxa. We constructed a minimum convex polygon for each species, using information from literature and biological collections. Individual maps were superimposed on a map of Argentina divided into cells of 25 km on each side. For each cell, we calculated the species richness, which varied between 1 and 21 species, and its degree of endemism, which fluctuated between 0.001 and 3.28. There were 30 species of sigmodontine rodents distributed almost exclusively in Argentina, most of them restricted to forested areas (Southern Andean Yungas) or to arid and semiarid environments (High and Low Monte and Patagonian Steppe). Areas with high species richness and endemism scores corresponded grossly with the Southern Andean Yungas, the Humid Chaco plus the Paraná flooded savannas, the Alto Parana Atlantic forests plus the Araucaria moist forests, the High Monte and the ecotone between the Patagonian steppe and the Valdivian temperate forests. A reassessment of the conservation status of sigmodontine rodents distributed in Argentina retrieved 2 extinct species, 7 endangered, 7 vulnerable, 6 near threatened and 13 data deficient. These numbers suggest a much more serious situation than the expressed by previous evaluations, highlighting the urgent need to establish conservation measures for the protection of this group. Los roedores sigmodontinos, con 86 géneros y ~430 especies vivientes, constituyen una de las radiaciones más exitosas de mamíferos neotropicales. En esta contribución, estudiamos los rangos de distribución de 108 especies de sigmodontinos en Argentina. Nuestros objetivos fueron (i) establecer patrones geográficos de riqueza de especies y endemismo y (ii) evaluar el estado de conservación regional de estos taxones. Construimos un polígono convexo mínimo para cada especie, utilizando información de la literatura y colecciones biológicas. Los mapas individuales fueron superpuestos en un mapa de Argentina dividido en celdas de 25 km de lado. Para cada celda, calculamos la riqueza de especies, que varió entre 1 y 21, y su grado de endemismo, que fluctuó entre 0.001 y 3.28. Hubo 30 especies de roedores sigmodontinos distribuidos casi exclusivamente en Argentina, la mayoría de ellos restringidos a áreas boscosas (Yungas andinas del sur) o a ambientes áridos y semiáridos (Monte alto y bajo y Estepa Patagónica). Las áreas con mayor riqueza de especies y valores más altos de endemismo se correspondieron groseramente con las Yungas andinas del sur, el Chaco húmedo más las Sabanas inundadas de Paraná, el Bosque Atlántico del Alto Paraná más los Bosques húmedos de araucaria, el Monte alto y el ecotono entre la Estepa Patagónica y los Bosques templados valdivianos. Una reevaluación del estado de conservación de los roedores sigmodontinos distribuidos en Argentina recuperó 2 especies extintas, 7 en peligro, 7 vulnerables, 6 casi amenazadas y 13 con datos deficientes. Estas cifras sugieren una situación mucho más grave que la expresada en evaluaciones anteriores, destacando la necesidad urgente de establecer medidas de conservación para la protección de este grupo. Fil: Formoso, Anahí Elizabeth. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; Argentina Fil: Teta, Pablo Vicente. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina

Zootaxa came as a new and innovative publication medium for taxonomy, amidst a scenario of devaluation of this important biological science. After 20 years, it has ascertained itself as one of the main journals in animal taxonomy. However, the contribution of the journal to the taxonomy of Mammalia (mammals), one of the most studied groups of animals with a long-standing, dedicated spectrum of specialized journals (mammalogy), could have been expected as minor. All the current and former editors of the Mammalia section of Zootaxa analyzed the relative contribution of the journal to the description of new species of mammals since 2001. We also analyzed the contribution of Zootaxa by taxon, geographic origin of taxa, and geographic origin of first authors. The taxonomic methodology of authors in species description is described as well as the temporal trends in publications and publication subjects. We highlight the editors’ picks and eventually, the challenges for the future. We found that Zootaxa has had a significant contribution to mammalogy, being the second journal (the first being Journal of Mammalogy) in terms of number of new species described (76; 10.6% of the new mammalian species described between 2001 and 2020). The majority of the new species were described following an integrative taxonomic approach with at least two sources of data (86%). The analysis of published taxa, their geographic origin, and the country of origin of first authors shows a wide coverage and exhaustive representation, except for the species from the Nearctic. We conclude that Zootaxa has likely responded to a repressed demand for an additional taxonomic journal in mammalogy, with as possible appeals the absence of publication fees and an established publication speed. With 246 articles published in the past 20 years, the Mammalia section of Zootaxa embraces a large spectrum of systematic subjects going beyond alpha taxonomy. The challenges for the future are to encourage publications of authors from the African continent, still poorly represented, and from the palaeontology community, as the journal has been open to palaeontology since its early days.

Molecular genetic data are increasingly used to assist in species identification and delimitation, and provide a powerful tool to detect conservation units (population/s of an organism considered to be different for conservation purposes). In combination with distributional and ecological information, molecular genetic data can contribute to establishing the conservation status of species and populations. Here, we review these applications to rodent species in Argentina, a diverse assemblage of some 200 species. We capitalize on recent efforts to establish the conservation status of mammals in Argentina and combine this information with available molecular genetic data for rodents in this country. This portion of the southern South America offers exceptional cases of population differentiation and species diversification related to a wide and diverse geography, which includes varied landscapes such as the Patagonian steppe, Andean highlands, tropical and subtropical forests, and the Monte and Pampa regions. Many species are data deficient (including no or limited genetic data) and only known from their type localities. Among the remaining species, most have at least some available mitochondrial DNA sequence data and these, coupled with morphological, karyotypic and (less frequently) nuclear DNA sequence or microsatellite data have been instrumental in identifying and delimiting species. In general, multilocus data with the desirable geographical density are lacking for all but a few species that have been studied in greater detail. Studies coupling genetic and ecological data (e.g. landscape or ecological genetics) are limited to a handful of more intensively studied cases. Given that habitat loss and fragmentation are among the major threats for survival of natural populations, assessing the extent of these threatening processes is crucial in conservation management and a priority in studies of conservation biology.

The genus Ctenomys Blainville, 1826 is, with 64 living species, one of the most species-rich genera of Mammalia. In this chapter, structured in two main sections, we discuss distinct issues related to the taxonomy and phylogeny of these rodents. Each section begins with a short historical summary and then focuses on the current state of knowledge. We provide a list of currently considered distinct species (remarking on departures from the most recent tuco-tuco taxonomic catalog), discuss candidate species, and unavailable names (i.e., those never properly published, such as C. “chasiquensis” or C. “yolandae”). In what constitutes the single nomenclatorial act of this contribution, we propose that C. azarae Rusconi and C. porteuosi Thomas are subjective junior synonyms of C. mendocinus Philippi. We provide a historical perspective about phylogenetic studies of tuco-tucos, remarking on species relationships and species groups, and summarizing the contents of the species groups. We also synthesize the available dating studies for this genus. In each section, we also highlight gray areas that need to be the focus of future research.

The anthropic effect associated with worldwide European settlements over the last 500 years has caused dramatic environmental changes, modified regional patterns of biodiversity, and often led to local or complete extinctions. The sigmodontine rodents of Bahía Samborombón (Humid Pampas, central-eastern Argentina) constitute a good case study: a late Holocene archaeological site allowed us to compare a pre-European settlement assemblage (12 species) with the extant one (nine species). We used linear morphometrics (16 cranial and ten mandibular measurements) to assess interspecific morphological variations of the masticatory apparatus in relation to dietary habits for each assemblage. Even though sigmodontines have a tendency towards omnivory, groups based on dietary preference only overlapped partially. Size was one of the main variables involved in niche segregation, and shape characteristics such as rostrum elongation or mandible robustness were linked to different diets. We found that a combination of dietary preference and size was associated with extinctions. The main morphospace change between the two assemblages was related to the local extinction of the three greater insectivores and the smallest graminivore, located towards the center of the assemblage’s morphospace. An insectivore was incorporated, involving no significant changes in the general morphospace. Graminivores and larvivores were not affected. Our study sheds light on the causes of local extinctions of small mammals at the Humid Pampas, a phenomenon that had never been studied from an ecomorphological approach. Fil: Barbero, Sofía. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina Fil: Teta, Pablo Vicente. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina Fil: Cassini, Guillermo Hernán. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina. Universidad Nacional de Luján. Departamento de Ciencias Básicas; Argentina

Sobre la distinción y disponibilidad de los nuevos taxones propuestos por Agnolin et al. 2019. Recientemente, Agnolin et al. (2019) describieron 14 especies nuevas de mamíferos, incluyendo 12 roedores, un murciélago y un carnívoro, y una nueva subespecie de roedor. Además, estos autores propusieron varios otros actos nomenclatoriales: algunas formas nominales se eliminaron de las sinonimias y se hipotetizaron como especies distintas; se nombraron tres nuevos géneros, una subtribu y una tribu demamíferos. Revisamos todos los actos nomenclatoriales propuestos por Agnolin et al. (2019) y concluimos que las 14 nuevas especies y la nueva subespecie, así como las formas eliminadas de las sinonimias, deben tratarse como sinónimos de especies ya conocidas. Sugerimos lo mismo con respecto a los tres nuevos taxones supraespecí cos presentados por Agnolin et al. (2019), de los cuales dos no están disponibles ya que no cumplen con las disposiciones del Código Internacional de Nomenclatura Zoológica. Terminamos esta contribución criticando la forma en que Agnolin et al. (2019) realizaron su abordaje taxonómico. Recently, Agnolin et al. (2019) described 14 new species of mammals, including 12 rodents,one bat, and one carnivore, and one new subspecies of rodent. In addition, these authors proposed severalother nomenclatorial acts: some nominal forms were removed from synonymies and hypothesized as distinctspecies, at the time that three new genera, one subtribe, and one tribe of mammals were also named. Wereviewed the merits of all nomenclatorial acts proposed by Agnolin at al. (2019) and concluded that all 14new species and the new subspecies, as well as those forms removed from synonymies, should be treatedas synonyms of already known species. We suggest the same regarding the three new supraspecic taxapresented by Agnolin et al., two of which are not available as they fail to comply with the provisions of theInternational Code of Zoological Nomenclature. We end this contribution criticizing the way that mammaltaxonomy was approached by Agnolin et al. (2019). Fil: Teta, Pablo Vicente. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina Fil: D'elía, Guillermo. Universidad Austral de Chile; Chile Fil: Jayat, Jorge Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; Argentina Fil: Gonçalves, Pablo Rodrigues. Universidade Federal do Rio de Janeiro; Brasil Fil: Simoes Libardi, Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Diversidad y Evolución Austral; Argentina. Universidade do Sao Paulo. Escola Superior de Agricultura Luiz de Queiroz; Brasil Fil: Oliveira, João Alves de. Universidade Federal do Rio de Janeiro. Museu Nacional; Brasil Fil: Moratelli, Ricardo. Fundación Oswaldo Cruz; Brasil Fil: Reis Percequillo, Alexandre. Universidade do Sao Paulo. Escola Superior de Agricultura Luiz de Queiroz; Brasil Fil: Prado, Joyce Rodrigues do. Universidade do Sao Paulo. Escola Superior de Agricultura Luiz de Queiroz; Brasil Fil: Ortiz, Pablo Edmundo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Correlación Geológica. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Departamento de Geología. Cátedra Geología Estructural. Instituto Superior de Correlación Geológica; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Instituto Miguel Lillo; Argentina Fil: Hurtado, Natali. Universidad Nacional de San Agustin; Perú Fil: Schiaffini, Mauro Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Centro de Investigación Esquel de Montaña y Estepa Patagónica. Universidad Nacional de la Patagonia "San Juan Bosco". Centro de Investigación Esquel de Montaña y Estepa Patagónica; Argentina. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Ciencias Naturales - Sede Esquel. Laboratorio de Investigaciones en Evolución y Biodiversidad; Argentina Fil: Abreu Jr., Edson Fiedler de. Universidade do Sao Paulo. Escola Superior de Agricultura Luiz de Queiroz; Brasil Fil: Chiquito, Elisandra Almeida. Instituto Nacional da Mata Atlântica; Brasil Fil: Giménez, Analía Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Centro de Investigación Esquel de Montaña y Estepa Patagónica. Universidad Nacional de la Patagonia "San Juan Bosco". Centro de Investigación Esquel de Montaña y Estepa Patagónica; Argentina. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Ciencias Naturales - Sede Esquel. Laboratorio de Investigaciones en Evolución y Biodiversidad; Argentina Fil: Torres, Julio. Instituto de Investigación Biológica del Paraguay; Paraguay

En esta nota reportamos tres nuevos especímenes de Abrothrix (Angelomys) xanthorhina para Isla de los Estados, en el extremo austral de Argentina, que son representativos de la forma nominal Akodon llanoi Pine 1976. Estos son los primeros especímenes de referencia desde su descripción, hace más de cuatro décadas. Adicionalmente, proveemos datos morfométricos para estos ejemplares y una actualización de la distribución de esta especie en la isla. En virtud de su rareza y su condición de endemismo insular, sumada a la presencia de Rattus norvegicus en Isla de los Estados, sospechamos que el estado de conservación de este ratón estaría comprometido. In this note we report three new specimens of Abrothrix (Angelomys) xanthorhina from Isla de los Estados, southernmost Argentina, which are representative of the nominal form Akodon llanoi Pine 1976. These are the first voucher specimens since the species description, more than four decades ago. In addition, we provide morphometric data for these specimens and update the distribution of the species on the island. Because of its rarity and isolated condition, added to the presence of Rattus norvegicus in Isla de los Estados, we suspect that the conservation status of this population could be compromised. Fil: Sánchez, Julieta. Universidad Nacional de Tierra del Fuego. Instituto de Ciencias Polares, Recursos Naturales y Ambiente; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina Fil: Teta, Pablo Vicente. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina Fil: Poljak, Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina. Universidad Nacional de Tierra del Fuego. Instituto de Ciencias Polares, Recursos Naturales y Ambiente; Argentina Fil: Lanusse, Lucas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina Fil: Balza, Ulises. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina Fil: Salom, Amira. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina Fil: Lois, Nicolás Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentina Fil: Lizarralde, Marta Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina

We conducted a geometric morphometric analysis to investigate the morphological variation of the golden wolf, Canis lupaster, and to clarify the morphological and taxonomic affinities of different taxa of the genera Canis and Lupulella. We suggest that the variation observed within the complex of Canis lupaster may be incompatible with what would be expected for a single species. We hypothesize that the nominal form C. l. soudanicus is a synonym of Lupulella adusta rather than being part of the golden wolf complex. The subspecies C. l. bea has a generalized jackal morphology (i.e., clusters together with L. mesomelas and C. aureus) and C. l. lupaster occupies an intermediate morphospace position, between jackal-like forms and wolf-like forms. These results contrast with previously published molecular analysis in which mitochondrial data failed to identify differences among golden wolf populations, and nuclear evidence points to the existence of groups that are incompatible with those recovered by morphological analysis. Regarding other jackals, our results depict the absence of morphological overlap between L. m. mesomelas and L. m. schmidti and no differences between putative subspecies of L. adusta. We call attention to the need for more integrative approaches to solve the taxonomic questions in various African Canidae. Fil: de Andrade Machado, Fabio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina. University of Massachussets; Estados Unidos Fil: Teta, Pablo Vicente. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina

Background Leptospirosis is a zoonotic disease that can be transmitted by contact with the urine of infected mammals. Rodents play a mayor role in the transmission of leptospires to humans. The province of Santa Fe reports the greatest number of cases in Argentina. Yet, in this region, there are still knowledge gaps regarding the diversity of rodent species that may be hosts of pathogenic leptospires. The aims of this study were to evaluate the presence of leptospiral antibodies in rodents from three riverside communities of Santa Fe, and to identify factors associated with leptospiral infection. Methodology/Principal findings Each community was divided into three environmental settings based on the level of human disturbance, and sampled during two springs (Sep-Oct 2014 and 2015) and one autumn (Mar-Apr 2015). Serum samples of captured sigmodontine and murine rodents were tested for leptospiral antibodies by enzyme-linked immunosorbent assay (ELISA), and microagglutination test (MAT) was used to assess the infecting serovar in seropositive individuals. Factors influencing seropositivity were analyzed using logistic regression models. We caught 119 rodents, of which 101 serums were suitable for analysis. Most frequently trapped species were Scapteromys aquaticus, Akodon azarae and Oligoryzomys spp., with seroprevalences of 41.3%, 42.9% and 55% respectively. Seropositivity was higher in individuals with an average body condition score and in those that were sexually mature, but in the latter the differences were marginally significant. Conclusions/Significance Our results suggest that native rodents may be playing a role in the environmental circulation of pathogenic leptospires and provide relevant information for public health policies in the area., Author summary Rodents are considered as the main reservoirs of pathogenic leptospires, which can cause leptospirosis, a disease that can be severe for both humans and domestic animals. Multiple socio-environmental factors have been found to influence the risk of leptospirosis, and many mammal species can play a role in the transmission of the bacteria. The purpose of this study was to investigate the local conditions and rodent fauna that may influence the risk of leptospirosis in communities located in the floodplains of the Parana river, near Santa Fe, Argentina. We conducted a survey of antibodies against leptospires in rodents from the center, border, and outside of three riverside settlements. We observed a relatively high seroprevalence among captured individuals (42%). Animals with an intermediate body condition were more likely to be seropositive. In most sites, native rodents were dominant over introduced rats and mice and lived close to human dwellings. Given the socio-environmental conditions observed in these settlements and the high frequency of floods that affect them, the presence of potentially infected rodents provide ample opportunities for leptospirosis to affect these communities.

Ctenomys Blainville 1826 is one of the most diverse genera of South American caviomorph rodents. Currently, six species of this genus are reported from Patagonia, south of 42◦S. In this contribution, we assessed the taxonomic status of several populations from eastern and central Chubut province, northern Patagonia. Based on phylogenetic analyses of DNA sequences, morphology assessment (qualitative and quantitative), and previously published karyological data, we describe three new species of this genus, one formed by two subspecies, endemic to northern Patagonia. In addition, we include C. coyhaiquensis Kelt and Gallardo 1994 into the synonymy of C. sericeus J.A. Allen 1903. Finally, we discussed the need for additional integrative approaches, including field collection of specimens, to better understand the diversity of this highly speciose rodent genus. Fil: Teta, Pablo Vicente. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina Fil: D Elía, Guillermo. Universidad Austral de Chile; Chile

Fil: Lanzone, Cecilia. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Nordeste. Instituto de Biologia Subtropical. Instituto de Biologia Subtropical - Nodo Posadas | Universidad Nacional de Misiones. Instituto de Biologia Subtropical. Instituto de Biologia Subtropical - Nodo Posadas; Argentina

El género Galea (Rodentia, Caviidae) incluye cinco especies vivientes y dos extintas de cávidos terrestres y herbívoros, que ocupan pastizales y matorrales rocosos, tanto en áreas altas como bajas de América del Sur. Algunas muestras fósiles del Pleistoceno-Holoceno del centro-este de Argentina han sido referidas como Galea sp., G. musteloides o G. cf. musteloides y finalmente se describieron como una nueva especie bajo el nombre de G. tixiensis. Sin embargo, estudios recientes basados en series grandes de individuos fallaron en encontrar diferencias morfológicas cualitativas entre G. lecucoblephara y G. tixiensis. Sobre la base de estos hallazgos, en esta contribución revisamos el estatus taxonómico de la especie extinta G. tixiensis. Se examinaron 110 individuos de las tres subespecies actualmente reconocidas de G. leucoblephara (i.e., G. l. demissa, G. l. leucoblephara y G. l. littoralis) de Argentina, Bolivia y Paraguay. Se registraron nueve medidas cráneo-dentarias. Los datos cuantitativos se sometieron a un análisis de componentes principales (PCA) con el fin de identificar la contribución de cada medida a la varianza total. Los caracteres cualitativos se evaluaron a través de las comparaciones de los rasgos supuestamente diagnósticos de G. tixiensis con la variabilidad representada por las muestras recientes. Los espacios multivariados de las tres subespecies estudiadas se superpusieron ampliamente en el PCA, lo que sugiere que estos taxones no difieren significativamente en la figura del cráneo. El holotipo de G. tixiensis se ubicó dentro del morfoespacio correspondiente a muestras recientes de G. l. littoralis. Los caracteres cualitativos supuestamente diagnósticos de G. tixiensis también se verificaron en muestras recientes de G. leucoblephara, en particular de G. l. littoralis. Sobre la base de sus rasgos craneanos cualitativos y cuantitativos se sugiere que G. tixiensis es un sinónimo de G. leucoblephara. Los mayores valores para algunos rasgos craneanos cuantitativos en las muestras fósiles –comparadas con las actuales– son reinterpretados en este trabajo como una respuesta ecofenotipica a las condiciones climáticas más severas durante el Holoceno. The genus Galea (Rodentia, Caviidae) includes five living and two extinct species of terrestrial and herbivorous cavies that inhabit grasslandsand rocky scrub areas at both high and low elevations in South America. Fossil samples from the late Pleistocene-Holocene from central-easternArgentina have been referred to as Galea sp., G musteloides or G. cf. musteloides and finally described as a new species under the name of G. tixiensis. However, recent studies based on large series of individuals fail to find qualitative morphological differences between G. leucoblephara and G.tixiensis. Based on these findings, in this contribution we reviewed the taxonomic status of the fossil species G. tixiensis. A total of 110 individualsof the three currently recognized subspecies of G. leucoblephara (i. e., G. l. demissa, G. l. leucoblephara and G. l. littoralis) from Argentina Boliviaand Paraguay were examined. Nine craniodental measurements were recorded. Quantitative data were subjected to a principal component analysis (PCA) in order to identify the contribution of each measurement to the total variance. Qualitative characters were evaluated through the comparisons of the diagnostic traits of G. tixiensis with the variability derived from the recent samples. PCA showed a high overlap of the multivariate spaces of the three subspecies studied, suggesting that they do not differ significantly in terms of cranial shape. The holotype of G. tixiensis was allocated within the morphospace of the recent G. l. littoralis samples. Qualitative traits diagnostic of G. tixiensis were also recorded in recent samples of G. leucoblephara, in particular of G. l. littoralis. Based on both qualitative and quantitative cranial traits, we suggest that G. tixiensis is a synonym of G. leucoblephara. The morphological traits supposedly unique to G. tixiensis were also recorded in specimens of living populations of G. l. littoralis. The large values of some quantitative cranial traits in fossil samples -compared to living ones- are reinterpreted here as an ecophenotypical response to the more severe climatic conditions of the Holocene. Fil: Teta, Pablo Vicente. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales ; Argentina Fil: Campo, Denise Heliana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales ; Argentina

Rodents are a very diverse group with large chromosome variability. One of the most species rich linage in the Neotropics is the Sigmodontinae. Among them, the tribe Abrotrichini was recently defined and its taxonomy and phylogeny were mostly elucidated through molecular and morphological evidence. Meanwhile, chromosome data were only secondarily used because of fragmentary information. In this contribution, we conduct a chromosome characterization of Abrothrix hirta, A. olivacea, A. andina, and Paynomys macronyx, review the cytogenetic background of the tribe, and contrast it with molecular data. Chromosomes were analyzed by conventional and differential techniques. All Abrothrix species presented 2n = 52/FNa = 56, with a high similarity in the banding patterns reflecting a conserved karyotype, which does not coincide with its high molecular variability. In turn, P. macronyx have 2n = 54/FNa = 58–59, varying due to a heteromorphic pair of autosomes. In addition, in this last species, different morphologies of the X chromosome and the presence of B chromosomes were detected. Heterochromatin was involved in these variants. The telomeric probe in P. macronyx marks terminal regions of all chromosomes. B chromosomes generated strong telomeric signals. The Ag-NORs banding revealed the same patterns in Abrothrix and Paynomys. Cytogenetic data support phylogenetic relationships previously proposed and suggest that the specious genus Abrothrix could have retained the ancestral karyotype of the subfamily. In the tribe, the relatively conserved chromosome complement contrasts with its high molecular variability. This indicates decoupling between the rates of chromosomal and molecular divergence, as observed in other rodent lineages. In abrotrichines, chromosome evolution was slower., Facultad de Ciencias Naturales y Museo

La tribu Abrotrichini (Rodentia, Cricetidae) es uno de los clados de Sigmodontinae más recientemente diagnosticados. Su distribución es fundamentalmente andino-patagónica, con mayor diversidad de especies en el sur de Argentina y Chile. En esta tesis se evaluaron las relaciones filogenéticas entre sus integrantes, utilizando 21 taxones terminales (20 vivientes y uno fósil) y un grupo externo (Wiedomys). Se realizó un análisis cladístico a través de búsquedas exactas y heurísticas de 99 caracteres morfológicos (16 del tegumento, 42 craneanos, 29 dentarios, 4 postcraneanos, 7 sexuales masculinos y 1 del aparato digestivo) y dos marcadores moleculares (uno mitocondrial [citocromo b; 746 pares de bases] y otro nuclear [IRBP, proteína intersticial de unión al retinol; 1137 pb]). Los datos fueron considerados por separado y en conjunto, bajo pesos iguales e implicados. En todos los casos se recuperó una división mayor entre un clado de formas cursoriales-escansoriales (Abrothrix) y otro de formas semifosoriales a fosoriales (Chelemys, Geoxus, Notiomys, Pearsonomys). El análisis cladístico corroboró la monofilia de Abrothrix, aunque a juzgar por el grado de diferenciación morfológica entre grupos de especies queda abierta la posibilidad de que este taxón pueda escindirse en al menos cuatro entidades de nivel genérico. Dentro del clado de formas fosoriales, las dos especies reconocidas para Chelemys no formaron un grupo monofilético y se confirmó la parafilia de Geoxus con respecto a Pearsonomys. Para ajustar el esquema clasificatorio con la hipótesis filogenética presentada en esta tesis se describe un género nuevo para contener a “Chelemys” macronyx y se incluye a Pearsonomys en la sinonimia de Geoxus. Se ofrecen diagnosis enmendadas para todos los géneros de Abrotrichini, aclarando los límites y contenidos de cada uno. En una segunda instancia, se estudió la taxonomía alfa de Abrothrix longipilis, uno de los abrotriquinos más ampliamente distribuidos en Argentina y Chile. Se realizó un análisis morfológico cualitativo (seis caracteres discretos) y cuantitativo (18 medidas cráneo-dentarias) de 471 especímenes, agrupados primero según un criterio geográfico y luego según su pertenencia a los clados definidos por un estudio filogeográfico previo. Los análisis multivariados (análisis de componentes principales, análisis discriminantes “libres de tamaño”) indican que en su actual concepción, A. longipilis es un complejo que incluye por lo menos dos especies, A. longipilis s.s. (restringida al centro de Chile) y A. hirta (sur de Chile y sudoeste de Argentina). Las poblaciones de A. hirta mostraron una correspondencia moderada entre los patrones filogeográficos y de variación fenotípica. Preliminarmente, puede considerarse que el tamaño en A. hirta se vincula más estrechamente con las características del ambiente (con los individuos más grandes en áreas boscosas, de mayor productividad primaria y los más pequeños en ambientes áridos, de menor productividad) antes que con su pertenencia a los distintos clados. En este escenario, la divergencia morfológica podría estar mayormente determinada por la selección diferencial a lo largo de un gradiente ambiental extremo y sería independiente de la cantidad de flujo génico (modelo de divergencia con flujo génico). Finalmente, se revisaron las formas fósiles Plio-Pleistocénicas de Abrothrix, incluyendo Akodon (Abrothrix) kermacki, A. (Ab.) magnus y aff. Abrothrix. El estudio de la morfología dentaria permitió referir los dos primeros taxones, recuperados de sedimentos pliocénicos del sudeste de la provincia de Buenos Aires, a la tribu Akodontini. El análisis cladístico sugiere que el fósil identificado como aff. Abrothrix del Plioceno-Pleistoceno de la provincia de Jujuy corresponde a una nueva especie que se vincula con A. jelski, que habita actualmente en la misma región. Bajo esta hipótesis taxonómica no habría registros extra-limitales para el género Abrothrix, tal como se infería de esquemas previos. Como corolario, se remarca la importancia de combinar evidencias morfológicas y genéticas, tanto para resolver interrogantes a nivel taxonómico como así también para lograr un esquema clasificatorio refinado a nivel de las especies fósiles por sus profundas implicaciones en la biogeografía histórica y evolución de estos roedores.

We document a new locality for the rare sylvan sigmodontine Abrawayaomys ruschii from Misiones, Argentina. The individual, recognized by its distinctive spiny hairs, was recovered from a scat of an ocelot, Leopardus pardalis (Mammalia, Felidae). This record contributes to f ll the gap between previous localities. Documentamos una nueva localidad para el raro ratón selvático Abrawayaomys ruschii, en la provincia de Misiones, Argentina. El individuo, reconocido por sus pelos espinosos distintivos, fue recuperado del excremento de un ocelote, Leopardus pardalis (Mammalia, Felidae). Este registro contribuye a llenar el vacío entre localidades previas. Fil: Cruz, María Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Universidad Nacional de Misiones. Instituto de Biología Subtropical; Argentina. Centro de Investigaciones del Bosque Atlántico; Argentina Fil: Teta, Pablo Vicente. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina Fil: Palacio, Lucía Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Universidad Nacional de Misiones. Instituto de Biología Subtropical; Argentina Fil: Paviolo, Agustin Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Universidad Nacional de Misiones. Instituto de Biología Subtropical; Argentina. Centro de Investigaciones del Bosque Atlántico; Argentina Fil: Di Bitetti, Mario Santiago. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Universidad Nacional de Misiones. Instituto de Biología Subtropical; Argentina. Centro de Investigaciones del Bosque Atlántico; Argentina. Universidad Nacional de Misiones. Facultad de Ciencias Forestales; Argentina

In this note, I discuss the advantages of the usage of subgenera as a practical taxonomic rank in mammalian taxonomy. Use of this category preserves traditional usage, reduces nomenclatural instability and avoids unnecessary change of names. Subgenera are useful to label diagnosable clades of closely related species, especially in morphologically and ecologically diverse monophyletic genera, without alteration of traditional binomial usage. Contrary to informal names such as "divisions" or "groups", subgenera are governed by the rules of the International Commission on Zoological Nomenclature (ICZN), having usage constrained (and stability promoted) by typification and priority. Fil: Teta, Pablo Vicente. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina

The genus Myoprocta Thomas, 1903 includes two living species of medium-sized caviomorph rodents of the family Dasyproctidae, the red acouchi, Myoprocta acouchy (Erxleben 1777), and the green acouchi, Myoprocta pratti Pocock 1913. Whereas some recent revisionary work has considered both species to be allopatrically distributed, other reports suggest that both taxa co-occur in eastern Colombia. In this contribution, I revaluate some qualitative and quantitative skull traits within Myoprocta to clarify its taxonomy and distribution. Multivariate analyses of quantitative skull characters support the distinction between M. acouchy and M. pratti, contradicting the findings of some previous authors. Based on these results and the examination of ~100 skins, I concur with the hypothesis that the two species are allopatrically distributed.

We study the geographical variation of the skull in the cavies Microcavia australis and M. maenas and its association with environmental variables. We tested four hypotheses previously proposed to explain the geographic patterns of morphological variation i) heat conservation; ii) heat dissipation; iii) primary productivity and iv) seasonality. We used 16 cranial measurements taken from 180 individuals. We analyzed the spatial variation in cranial morphology through Generalized Additive Models. Both species showed a north-south clinal gradient in skull size (increasing towards colder, less seasonal environments, with lower summer rainfalls in M. australis and towards warmer and seasonal environments in M. maenas). Microcavia australis presented greater ecomorphological variability than M. maenas, in agreement with its wider distribution and occurrence in more diverse environments. Also, the length of tympanic bullae in M. australis was larger towards its northern distributional range (associated to smaller skulls), and smaller to the south (associated to larger skulls). Overall, the distributional range of both species coincided with unproductive environments, where temperature represents a limiting factor and, together with rainfall, might determine the observed morphological patterns.

The Patagonian assemblage of small mammals has long fascinated naturalists. Even when it is moderately diverse, several of its components are endemic to the region. One of these is the monotypic genus Notiomys, whose single species N. edwardsii is widely distributed in the steppes of Argentinean Patagonia. A dead mouse found in Parque Nacional Torres del Paine, Ultima Esperanza, Chile, which was determined as belonging to the species N. edwardsii. The just mentioned finding allows us to report the genus Notiomys for the first time to Chile. This result highlights the need of keeping doing field prospections even in areas whose mammal assemblages are presumably well characterized.

A new species of rodent is added to the highly diverse genus Oecomys (Cricetidae, Sigmodontinae, Oryzomyini) based on specimens collected in the Argentinian provinces of Chaco and Formosa. The new species is characterized by a derived carotid circulatory pattern, a feature shared with O. concolor, O. mamorae, and O. sydandersoni. A unique combination of morphological, morphometric, and molecular characters, however, provides unambiguous evidence of its validity as a separate entity. Individuals of the new species are larger than other representatives of Oecomys, and their skulls have wide and cuneate interorbital regions with well-developed supraorbital shelves, long incisive foramina, long palates, absent alisphenoid struts, and broad Eustachian tubes. This new Oecomys appears to be endemic to the Humid Chaco, an ecoregion listed as Vulnerable due to the human impact. Preliminary observations suggest that several specimens from Eastern Paraguay and the Brazilian Pantanal could also be assigned to the new species described herein., Una nueva especie es adicionada al altamente diverso género de roedores Oecomys (Cricetidae, Sigmodontinae, Oryzomyini), sobre la base de especímenes coleccionados en las provincias Argentinas de Chaco y Formosa. La nueva especie se caracteriza por un patrón de circulación carotídea derivado, un rasgo compartido con O. concolor, O. mamorae y O. sydandersoni. Sin embargo, la combinación única de caracteres morfológicos, morfométricos y moleculares provee evidencia inequívoca sobre su validez como una entidad separada. Individuos de la nueva especie son de mayor tamaño en comparación con otros Oecomys y sus cráneos tienen una región interorbitaria ancha y acuñada con plataformas supraorbitarias bien desarrolladas, forámenes incisivos largos, paladares largos, ausencia de las barras alisfenoideas y tubos de Eustaquio anchos. Este nuevo Oecomys parece ser endémico del Chaco Húmedo, una ecorregión considerada como Vulnerable debido al impacto antrópico. Observaciones preliminares sugieren que varios especímenes de Paraguay Oriental y del Pantanal Brasilero podrían también ser asignados a la nueva especie aquí descrita., Centro de Estudios Parasitológicos y de Vectores

La abundancia del gato montés (Leopardus geoffroyi), un pequeño felino silvestre sudamericano, se ha reducido principalmente por la destrucción de su hábitat y por la caza. En la Argentina, la mayoría de los estudios sobre la dieta del gato montés se llevaron a cabo en áreas protegidas y en sus alrededores, mientras que no existen estudios en sistemas puramente agrícolas. Describimos la composición de la dieta de L. geoffroyi y sus variaciones estacionales en un sistema agrícola con el fin de contribuir al conocimiento de su ecología e historia natural. Desde la primavera de 2008 hasta la primavera de 2011 analizamos un total de 494 heces e identificamos 695 ítems presa. La dieta incluyó 81.6% de mamíferos, lo cual representó 93.3% de la biomasa potencialmente ingerida. Entre los mamíferos, la presa principal fueron los roedores, que representaron 79.6% del total de los ítems presa y 59.4% del total de la biomasa potencialmente ingerida. Los pequeños roedores significaron una gran proporción de los ítems presa, mientras que las especies de mayor tamaño, como el cávido Cavia aperea, contribuyeron mayormente en función de la biomasa ingerida. La plasticidad de la dieta del gato montés podría permitir la persistencia de sus poblaciones en ecosistemas variables y antropizados. Geoffroy’s cat (Leopardus geoffroyi), a small wild cat of South America, showed in the last years a decline in population abundance mainly related to both habitat destruction and hunting. The increasing human population densities and the consequent demand for food and natural resources will rapidly erode and fragment its remaining habitats. In Argentina most studies about Geoffroy’s cat diet have been conducted in protected areas or in their surroundings, while there are no studies conducted in purely agricultural systems. We described the diet composition of Leopardus geoffroyi and its seasonal variations in an agricultural ecosystem to contribute knowledge of its ecology and natural history. The study was carried out from spring 2008 to spring 2011. A total of 494 scats were analyzed and at least 695 prey-items were identified. The diet included 81.58% of mammal prey, representing 93.32% of the potential biomass ingested. Within mammals, the principal prey were rodents, representing 79.57% of the total prey items and 59.39% of the total potential biomass consumed. Small rodents account for a great proportion of prey items, while larger species, as the caviid Cavia aperea, contributed more biomass. The diet plasticity may enhance the persistence of Geoffroy’s cat populations in variable and anthropized ecosystems.

The subfamily Dolichotinae (Rodentia, Caviidae) includes two living species (Dolichotis patagonum and D. salinicola) of cursorial, long-legged rodents that inhabit semiarid thorn scrubs and shrublands in southern South America. Some authors consider that the morphological differences between D. patagonum and D. salinicola warrant circumscription of the latter in its own genus, Pediolagus. Based on a phylogeny and divergence times grounded on molecular data, as well as a qualitative and quantitative assessment of morphological differences, the distinction between Dolichotis and Pediolagus is equal to or greater than differences seen for other intergeneric comparisons within Cavioidea. Based on these results, we argue that the taxonomic designations of Dolichotis and Pediolagus should be retained.

The present study analyzes zooarchaeological and palaeoenvironmental trends from an assemblage of small mammals recovered from Agua de la Tinaja (AT), an archaeological site from an intermountain valley of the Andean cordillera (northern Mendoza, Argentina). Small mammal remains recovered from AT, chronologically associated with 900–600 years BP, showed taphonomic traces corresponding to the action of owls and humans. Such results were included and compared within the framework of a resource intensification process suggested for Prehistoric human societies from northern Mendoza in Central Western Argentina. The small mammal assemblage from AT is composed by typical species from highland areas (Abrothrix andina, Microcavia australis, Phyllotis xanthopygus) mixed with some species from the Monte Desert (Calomys musculinus, Ctenomys sp., Eligmodontia sp., Thylamys pallidior) and Abrocoma sp. The co-occurrence of some species with modern allopatric distributions could support a scenario of greater environmental heterogeneity during the late Holocene than in the present. A situation like this could be consistent with a more dense vegetation cover and larger availability of patch resources. Fil: López, José Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Provincia de Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Universidad Nacional de Cuyo. Instituto Argentino de Investigaciones de las Zonas Áridas; Argentina. Universidad Nacional de Cuyo. Facultad de Filosofía y Letras. Instituto de Arqueología y Etnología; Argentina Fil: Fernández, Fernando Julián. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ingeniería; Argentina Fil: Teta, Pablo Vicente. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina Fil: Rosi, María Irene. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Provincia de Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Universidad Nacional de Cuyo. Instituto Argentino de Investigaciones de las Zonas Áridas; Argentina Fil: Sironi, Osvaldo Horacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina Fil: Bárcena, Joaquín Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Ciencias Humanas, Sociales y Ambientales; Argentina

Reliable identification of small mammal bone remains is crucial for several disciplines, including archaeology, biogeography, ecology, paleontology, taxonomy, and taphonomy. However, this issue is usually a challenging task, often complicated by the fragmentary nature of bone accumulations and/or by the taphonomic processes involved in the genesis of some assemblages. In this work, we provide dichotomous artificial keys for crania and mandibles of non-flying small mammal (

The genus Galea Meyen, 1833 includes at leastfive species of terrestrial, diurnal and herbivorous caviesthat occupy grasslands and rocky scrub areas at both highand low elevations in South America. According to theavailable molecular and morphological data, Galea comesThomas, 1919 is restricted to highland areas above 2000 min southern Bolivia and northwestern Argentina. Its distributionalrange as well as its morphological distinctivenessfrom other closely related species (Galea leucoblepharaand Galea musteloides) is poorly documented. Using bothqualitative and quantitative morphological traits, we providedan emended diagnosis for G. comes. In addition, weadded six new locality records to its known distribution Fil: Teta, Pablo Vicente. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina Fil: Madozzo Jaén, María Carolina. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; Argentina. Museo Paleontológico Egidio Feruglio; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Bezerra, Alexandra M.R.. No especifíca; Fil: Ortiz, Pablo Edmundo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Correlación Geológica. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Departamento de Geología. Cátedra Geología Estructural. Instituto Superior de Correlación Geológica; Argentina Fil: Lucero, Sergio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina Fil: Jayat, Jorge Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; Argentina

Our aim was to assess the effect of environmental factors on short temporal abundance variations of the two most abundant native rodents of agricultural agroecosystems, Akodon azarae and Calomys laucha. We conducted a 3-year longitudinal sampling of rodents, and recorded meteorological data such as temperature and precipitation, predation rate by Leopardus geoffroyi, Tyto furcata and Athene cunicularia, vegetation cover and height, characteristics of cropfields and their borders. The effect of these factors on rodent abundance was evaluated through generalized linear mixed models. Abundance variations of both rodent species were explained by characteristics of both cropfields and their borders. At the studied temporal scale, meteorological variables did not have a direct effect on abundance variations, but probably influenced through vegetation characteristics and were expressed in seasonal variations. For A. azarae there was also an effect of predation by L. geoffroyi (positive) and T. furcata (negative), while predation by A. cunicularia did not contribute to explain abundance variations of any species. Fil: Guidobono, Juan Santiago. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentina Fil: Cueto, Gerardo Ruben. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentina Fil: Teta, Pablo Vicente. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; Argentina Fil: Busch, Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentina

Ctenomys dorsalis is known only from its type specimen, a female preserved as skin without skull (except for the upper incisors) from an imprecise locality in the "Northern Chaco of Paraguay". Here, we report additional individuals of this species housed, since the 1940s, at the Field Museum of Natural History (Chicago, USA). Based on these specimens, which fully match the original description of this rodent, we provide novel information regarding its phylogenetic position, external and cranial morphology, and distribution. The analysis of mtDNA sequences supports the distinctiveness of this taxon and suggests its placement within the boliviensis group of Ctenomys. Our study highlights once more the importance of museum collections as repositories of biodiversity. Fil: Londoño Gaviria, Manuela. Field Museum of Natural History; Estados Unidos. Universidad Eafit; Colombia Fil: Teta, Pablo Vicente. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina Fil: Ríos, Sergio Daniel. Museo Nacional de Historia Natural del Paraguay; Paraguay. Secretaría Nacional de Cultura. Departamento de Arqueología y Paleontología; Paraguay Fil: Patterson, Bruce. Field Museum of Natural History; Estados Unidos

Analyses of morphological and molecular data indicate the existence of an unrecognized and unnamed species of soft-haired mouse, genus Abrothrix. Here, we name and describe this new species, which inhabits the Valdivian ecoregion, from the north of Chiloé Island onto the mainland in the Chilean regions of Los Lagos and Los Ríos; it also occurs at a single locality in the Argentinean province of Neuquén. Long confused with A. sanborni, the new species presents a unique combination of characters that differentiate it in external, cranial, phallic, and dental terms from its congeners. Phylogenetic analysis, based on cytochrome-b gene sequences, indicates that the new species is sister to a clade formed by the austral species A. lanosa and A. sanborni and differs on average from them by 5.7% and 5.2%, respectively. Results based on the nuclear Fgb-I7 locus are less conclusive regarding the phylogenetic position of the new species but also show its distinction. We comment on the conservation significance of our findings, considering that forests of the Valdivian ecoregion are suffering substantial human disturbance through intensive logging. Análisis de datos morfológicos y moleculares indican la existencia de una especie nueva e innominada de ratones del género Abrothrix. En este trabajo nominamos y describimos esta nueva especie que habita la ecorregión Valdiviana, desde el norte de la Isla de Chiloé hasta áreas continentales adyacentes de las regiones chilenas de Los Lagos y Los Ríos; la especie también ha sido registrada en una localidad de la provincia argentina del Neuquén. Largamente confundida con A. sanborni, la nueva especie presenta una combinación única de caracteres, incluyendo: coloración dorsal negruzca marrón oscuro a marrón-oliva; coloración ventral marrón grisácea a grisácea; cráneo delicado, con la constricción interorbital en forma de reloj de arena y caja craneana redondeada; rostro angosto y largo; nasales y premaxilares proyectados más anteriormente que los incisivos; placa cigomática estrecha; paladar extendiéndose apenas más allá del plano definido por el margen posterior de los M3; molares mesodontes; en adultos M1 sin flexo anteromedio; parastilo y mesolofo presentes; estómago unilocular-hemiglandular; cráter terminal del pene dirigido ventralmente; elementos apicales cartilaginosos ausentes. Análisis filogenéticos basados en secuencias del gen del citocromo b indican que la nueva especie es hermana de un clado formado por las especies australes A. lanosa y A. sanborni y que difiere de éstas en promedio 5.7 % y 5.2 %, respectivamente. Resultados basados en el locus nuclear beta fibrinógeno son menos conclusivos en relación a la posición filogenética de la nueva especie, aunque también muestran su distinción. Considerando que la ecorregión Valdiviana está sufriendo un impacto antrópico substancial, finalizamos el trabajo comentando sobre la relevancia de nuestro hallazgo para la biología de la conservación. Fil: D Elía, Guillermo. Universidad Austral de Chile; Chile Fil: Teta, Pablo Vicente. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina Fil: Upham, Nathan S.. Integrative Research Center; Estados Unidos. McMaster University; Canadá Fil: Pardiñas, Ulises Francisco J.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; Argentina Fil: Patterson, Bruce. Integrative Research Center; Estados Unidos

El huroncito patagónico (Lyncodon patagonicus) es un carnívoro pequeno, ˜ raro y muy poco conocido. Su distribución, que incluye varios registros fósiles e históricos, se extiende por el oeste de Argentina y sur de Chile. Según estudios recientes sus poblaciones estarían en retracción, afectándose su conservación. En este trabajo se registra una nueva localidad de presencia para esta especie basada en un individuo fotografiado en el Parque Nacional Lihue Calel, provincia de La Pampa. La importancia de este registro radica en que se localiza a 173 km hacia el suroeste de la referencia previa más cercana conocida y contribuye a rellenar un vacío amplio en el centro de su distribución geográfica, donde no existían registros previos. The Patagonian weasel (Lyncodon patagonicus) is a small, rare, and little known carnivore. Its distribution, which includes several fossil and historical records,spans western Argentina and southern Chile. According to recentstudies, its populations are declining, affecting its conservation. In this paper we report a new locality of occurrence for the species based on a photographed individual from Lihue Calel National Park, La Pampa Province. The importance of this record is that it is located 173 km southwest from the nearest previously known reference, and helps to fill a wide gap in the center of its range, where there were no previous records. Fil: Formoso, Anahí Elizabeth. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Diversidad y Evolución Austral; Argentina Fil: Dolsan, Marcelo. Provincia de La Pampa. Dirección de Recursos Naturales; Argentina Fil: Sosa, Ramón Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencias de la Tierra y Ambientales de La Pampa. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. Instituto de Ciencias de la Tierra y Ambientales de La Pampa; Argentina Fil: Teta, Pablo Vicente. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales ; Argentina

We describe a new living genus and species of Sigmodontinae currently only known from the Brazilian National Park Sempre Vivas, Minas Gerais State. This rodent is characterized by a unique combination of traits that include, among others, a long tail, with its distal tip (approximately 2.5 to 5 cm) entirely white; skull with domed profile; long rostrum with an incipient rostral tube; and noticeable small brachyodont molars with reduced mesolophs and mesostyles present on the 1st and 2nd upper molars. Cladistic analyses of molecular (1 mitochondrial and 1 nuclear marker) and morphological characters indicate that the new genus belongs to the Phyllotini and is sister to the remainder genera of this tribe. However, contrary to other known phyllotines, the new genus shows vestigial mesolophs and mesostyles. Phyllotines are widespread in open areas, in particular desert and semideserts, mostly in the western portion of South America. The new genus described herein expands the diversity of the tribe and suggests an ancient event of diversification in eastern Brazil. Describimos un nuevo género y especie de Sigmodontinae actualmente sólo conocido para el Parque Nacional brasilero Sempre Vivas, Estado de Minas Gerais. Este roedor se caracteriza por una combinación única de rasgos que incluyen, entre otros, una cola larga con su porción distal (ca. 2,5 a 5 cm) enteramente blanca; cráneo con perfil abovedado; rostro largo con tubo rostral incipiente; molares braquiodontos notablemente pequeños con pequeños mesolofos y mesostilos presentes en los primeros y segundos molares superiores. Análisis cladísticos de caracteres moleculares (un marcador mitocondrial y un marcador nuclear) y morfológicos indican que el nuevo género pertenece a los Phyllotini y es hermano de los restantes géneros de la tribu. Sin embargo, contrariamente a los otros filotinos conocidos, el nuevo género muestra mesolofos y mesostilos vestigiales. Los filotinos están ampliamente distribuidos en zonas abiertas, en particular en desiertos y semidesiertos, mayormente en la porción occidental de América del Sur. El nuevo género aquí descripto expande la diversidad de la tribu y sugiere un antiguo evento de diversificación en Brasil oriental. Fil: Pardiñas, Ulises Francisco J.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina Fil: Lessa, Gisele. Universidade Federal de Viçosa; Brasil Fil: Teta, Pablo Vicente. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina Fil: Salazar Bravo, Jorge. Texas Tech University; Estados Unidos Fil: Câmara, Edeltrudes M. V. C.. Universidade Católica de Minas Gerais; Brasil. Bicho do Mato Instituto de Pesquisa; Brasil

El género Lagidium Meyen 1833 incluye más de 20 formas nominales, la mayoría de ellas basadas en uno o dos ejemplares, descriptas entre finales del siglo XVIII y principios del XX. Revisiones posteriores redujeron este número a tres o cuatro especies, dependiendo del autor. Más recientemente, el uso de técnicas moleculares ha demostrado que esos números tampoco son representativos de la diversidad real de este género. Lagidium viscacia (Molina 1782) es un taxón ampliamente distribuido, con poblaciones desde el oeste de Bolivia hasta el sur de Argentina y Chile. Sin embargo, su variación morfológica y geográfica no ha sido evaluada con metodologías modernas y series extensas de ejemplares. En este trabajo se revisaron > 100 individuos, incluyendo pieles y cráneos colectados principalmente en Argentina. Se realizaron análisis multivariados (i. e., análisis de componentes principales, discriminantes) sobre un subconjunto de 55 ejemplares adultos agrupados según su procedencia geográfica y a partir de 16 medidas cráneo-dentarias. En los análisis de componentes principales y discriminantes se registró una superposición moderada entre individuos de distintas localidades del sur de Argentina por un lado y del noroeste de Argentina, oeste de Bolivia y norte de Chile por el otro. La coloración externa, a pesar de ser muy variable, mostró una predominancia de tonos grises hacia el sur de Argentina y amarillentos hacia el noroeste. Los especímenes del sur de Argentina, aquí referidos como L. moreni, se distinguieron por su mayor tamaño general, sus nasales más anchos y expandidos en su mitad anterior y por tener la raíz dorsal del proceso cigomático del maxilar angosta. Por el contrario, los ejemplares del noroeste de Argentina, que aquí optamos por mantener dentro del concepto de L. viscacia, poseen un menor tamaño general, los nasales angostos y sin expansiones y la raíz dorsal del proceso cigomático del maxilar ancha. Mountain viscachas of the genus Lagidium Meyen 1833 are medium-to-large hystricomorph rodents (1.5 -- 3 kg) that live in rocky outcrops from Ecuador to southern Argentina and Chile. Lagidium includes more than 20 nominal forms, most of them based on one or two individuals, which were first described during the 18th and 20th. Subsequent revisions reduced the number of species to three to four, depending upon the author. Within the genus, Lagidium viscacia (Molina, 1782) is the most widely distributed species, with populations apparently extended from western Bolivia to southern Argentina and Chile. We reviewed > 100 individuals of Lagidium, including skins and skulls, most of them collected in Argentina. We performed multivariate statistical analysis (i. e., principal component analysis [PCA], discriminant analysis [DA]) on a subset of 55 adult individuals grouped according to their geographical origin, using 16 skull and tooth measurements. In addition, we searched for differences in cranial anatomy across populations. PCA and DA indicate a moderate overlap between individuals from southern Argentina, on one hand, and northwestern Argentina, western Bolivia and northern Chile, on the other. The external coloration, although variable, showed a predominance of gray shades in southern Argentina and yellowish gray in northwestern Argentina. Specimens of southern Argentina were characterized by their bigger overall size, nasals expanded in its front half, and narrow dorsal root of the zygomatic process of the maxillary, while those of northwestern Argentina were smaller, with nasals lacking expansions and the dorsal root of the zygomatic process of the maxillary broad. Our study provides coincident results from quantitative and qualitative morphology that allow us to clearly differentiate southern Argentinean populations of Lagidium viscacia from those of northwestern Argentina and western Bolivia. The oldest available name for the populations from southern Argentina, sometimes referred as L. boxi, is moreni, a taxon with an unclear type locality. The status of the populations from northwestern Argentina and western Bolivia is relatively more complex, since at least eight nominal forms were described from this general area and because our sampling is far from being extensive. In addition, is also unclear if these populations correspond to one or more species, as well as their degree of differentiation from L. viscacia s. s. Without analyzing topotypes of all nominal forms and adequate samples across the entire distribution range, it is premature to put forward a formal taxonomic proposal; as such, at this moment we prefer to maintain those populations from northwestern Argentina, western Bolivia and central Chile under L. viscacia. Fil: Teta, Pablo Vicente. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina Fil: Lucero, Sergio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina

On the basis of an adult individual collected in 1955 plus 3 mandibles of latest Holocene age, we describe a new living species of the amphibious rat Holochilus (Sigmodontinae, Oryzomyini) from west-central Mendoza Province, Argentina. The new species is characterized by its short tail, broad zygomatic plate with rounded anterior-superior corner, bony palate without excrescences, large mesolophostyle in the upper first molars and complex upper third molar shorter than the second, and lacking the hypoflexus. The morphological traits displayed by this new Holochilus combine features observed in both the H. brasiliensis and H. sciureus groups with others unique among the genus (e.g., absence of hypoflexus). This new species is the southernmost expression of the genus along the western side of its current range, where it appears isolated in the middle part of the Río Atuel. The finding reported here uncovers and highlights unexpected diversity in southern South American arid lands., Facultad de Ciencias Naturales y Museo

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No. of bitstreams: 0 Previous issue date: 2016-11-23 Villanova Univ, Dept Biol, Villanova, PA 19085 USA Museu Nacl Hist Nat & Ciencia, Lisbon, Portugal Univ Brasilia, Dept Zool, Inst Ciencias Biol, BR-70910900 Brasilia, DF, Brazil Smithsonian Inst, Natl Museum Nat Hist, Washington, DC 20560 USA Sorbonne Univ, Museum Natl Hist Nat, ISYEB, Paris, France Univ Nacl Tucuman, San Miguel De Tucuman, Argentina King Saud Univ, Riyadh, Saudi Arabia Cornell Univ, Ithaca, NY USA Univ Fed Sao Paulo, Diadema, Brazil Upper Austrian Museum, Ctr Biol, Linz, Austria Villanova Univ, Villanova, PA 19085 USA Univ Salzburg, Salzburg, Austria Plazi, Bern, Switzerland Univ Brasilia, Brasilia, DF, Brazil Univ Sao Paulo, Ribeirao Preto, Brazil Zool Forsch Museum A Koenig, Bonn, Germany Museu Paraense Emilio Goeldi, Belem, Para, Brazil Russian Acad Sci, St Petersburg, Russia Pontificia Univ Catolica Rio Grande do Sul, Porto Alegre, RS, Brazil Museo Reg Sci Nat, Turin, Italy Univ Fed Rio Grande do Sul, Porto Alegre, RS, Brazil Royal Museum Cent Africa, Tervuren, Belgium Univ Nacl Autonoma Mexico, Mexico City, DF, Mexico Univ Innsbruck, Inst Ecol, Innsbruck, Austria Hasselt Univ, Hasselt, Belgium Univ Fed Pernambuco, Recife, PE, Brazil Univ Fed Espirito Santo, Vitoria, ES, Brazil Univ Nacl Misiones, Felix De Azara, Argentina Albany Museum, Grahamstown, South Africa Natl Museum, Bloemfontein, South Africa Senckenberg Nat Hist Sammlungen, Dresden, Germany Univ Estadual Paulista, Botucatu, SP, Brazil Stephen F Austin State Univ, Nacogdoches, TX 75962 USA Landesmuseum, Leonding, Austria Univ Camerino, Camerino, Italy Univ Fed ABC, Sao Bernardo, Brazil Univ Estadual Londrina, Museu Zool, Londrina, Parana, Brazil Senckenberg Res Inst, Frankfurt, Germany Museo Civ Storia Nat, Carmagnola, Italy Polskiej Akad Nauk, Muzeum & Inst Zool, Warsaw, Poland Museo Civ Storia Nat, Genoa, Italy Russian Acad Sci, Inst Zool, St Petersburg, Russia Univ Estadual Paulista, Sao Vicente, Brazil Sorbonne Univ, ISYEB, Museum Natl Hist Nat, Paris, France Port Elizabeth Museum, Port Elizabeth, South Africa Sam Noble Museum, Norman, OK USA Harvard Univ, Museum Comparat Zool, Cambridge, MA 02138 USA North West Univ, Potchefstroom, South Africa Museu Nacl, Rio De Janeiro, Brazil Nat Hist Museum, Basel, Switzerland Senckenberg Nat Kundemuseum, Gorlitz, Germany North Carolina Museum Nat Sci, Raleigh, NC USA Univ Rennes 1, Rennes, France Univ Sao Paulo, Museu Zool, Sao Paulo, SP, Brazil Amer Museum Nat Hist, New York, NY 10024 USA Univ Huddersfield, Huddersfield, W Yorkshire, England North Dakota State Univ, Fargo, ND USA Univ Sao Paulo, Sao Paulo, SP, Brazil Fac Sci Sfax, Sfax, Tunisia DPTC PC, Manaus, Amazonas, Brazil Louisiana State Univ, Museum Nat Sci, Baton Rouge, LA 70803 USA Zool Survey India, Kolkata, India Univ Tennessee, Chattanooga, TN USA Ohio State Univ, Columbus, OH 43210 USA Univ Luterana Brasil, Museu Ciencias Nat, Canoas, Brazil Univ Firenze, Florence, Italy Univ Ovidius Constanta, Constanta, Romania Univ Mississippi, Oxford, MS USA Royal Belgian Inst Nat Sci, Brussels, Belgium Univ New Mexico, Albuquerque, NM 87131 USA Inst Nacl de Pesquisas da Amazonia, Manaus, Amazonas, Brazil Univ Stellenbosch, Matieland, South Africa Univ Fed Minas Gerais, Belo Horizonte, MG, Brazil CIBIO Ctr Invest Biodiversidade & Recursos Genet, Vairao, Portugal Museum Hist Nat, Geneva, Switzerland Univ Fed Mato Grosso, Cuiaba, Brazil Univ Austral Chile, Valdivia, Chile Univ Malaysia, Sarawak, Malaysia Indian Inst Sci, Bangalore, Karnataka, India Scottish Assoc Marine Sci, Oban, Argyll, Scotland Sam Houston State Univ, Huntsville, TX 77340 USA Museo Nacl Ciencias Nat, Madrid, Spain Sorbonne Univ, CR2P, Museum Natl Hist Nat, Paris, France Drexel Univ, Acad Nat Sci, Philadelphia, PA 19104 USA Univ Richmond, Richmond, VA 23173 USA Ctr Pesquisas Cacau, Itabuna, Brazil Univ Torino, Turin, Italy Soc Hist Nat Alcide dOrbigny, Aubiere, France Wolfden Sci Consulting, Murcia, Spain Univ Fed Rio de Janeiro, Macae, Brazil Univ Tennessee, Knoxville, TN USA Inst Humboldt, Villa De Leyva, Colombia Escuela Politec Nacl, Quito, Ecuador Calif Acad Sci, San Francisco, CA 94118 USA Museum Dept Hist Nat Var, Toulon, France Nat Environm & Wildlife Soc, Angul, India Univ Kansas, Lawrence, KS 66045 USA Kyoto Univ, Kyoto, Japan Consejo Nacl Invest Cient & Tecn, Museo Argentino Ciencias Nat Bernardino Rivadavia, Buenos Aires, DF, Argentina Univ Fed Paraiba, Joao Pessoa, Paraiba, Brazil Univ Fed Parana, Curitiba, Parana, Brazil Univ Fed Rio de Janeiro, Rio De Janeiro, Brazil Nat Hist Museum Narodini Museum, Prague, Czech Republic Nat Hist Museum Zimbabwe, Bulawayo, Zimbabwe Ateneo Manila Univ, Quezon City, Philippines Pontificia Univ Javeriana, Bogota, Colombia RACINE, St Maugan, France Univ Paris 06, Sorbonne Univ Paris, ISYEB, Paris, France Ocean Univ China, Qingdao, Peoples R China Museo Nacl Hist Nat Paraguay, San Lorenzo, Paraguay Univ Carabobo, Valencia, Venezuela Natl Ctr Biol Sci, 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Jr Coll, Santa Rosa, CA USA George Washington Univ, Washington, DC 20037 USA Inst Teknol Bandung, Bandung, Indonesia Earlham Coll, Richmond, IN USA Senckenberg Forschungsinst & Nat Museum, Frankfurt, Germany Univ Estadual Londrina, Londrina, Parana, Brazil Univ Koblenz Landau, Koblenz, Germany Nat Hist Museum, London, England Ditsong Natl Museum Nat Hist, Pretoria, South Africa Bombay Nat Hist Soc, Bombay, Maharashtra, India Philipps Univ Marburg, Marburg, Germany Hess Landesmuseum, Darmstadt, Germany Smithsonian Conservat Biol Inst, Washington, DC USA Univ Pannonia, Keszthely, Hungary Staatliches Museum Nat Kunde, Stuttgart, Germany UFT, Tocantins, Portugal Museum Nat Kunde, Berlin, Germany Nat Hist Riksmuseet, Stockholm, Sweden Hikarigaoka, Munakata, Japan Inst Agr & Environm Sci, Tartu, Estonia Univ Los Andes, Merida, Venezuela Bat Jungle, Monteverde, Costa Rica Texas A&M Univ, College Stn, TX USA Yale Univ, New Haven, CT USA Univ Estadual Paulista, Sao Jose Do Rio Preto, Brazil Museo Nacl Hist Nat, Montevideo, Uruguay Consejo Nacl Invest Cient & Tecn, Fdn Miguel Lillo, San Miguel De Tucuman, Argentina Roger Tory Peterson Inst Nat Hist, Jamestown, VA USA Univ Fed Reconcavo Bahia, Cruz Das Almas, Brazil South China Normal Univ, Guangzhou 510631, Guangdong, Peoples R China Museu Ciencias Tecnol PUCRS, Porto Alegre, RS, Brazil Univ Fed Tocantins, Porto Nacl, Brazil Univ Toronto, Scarborough, ON, Canada Univ Nacl Colombia, Inst Ciencias Nat, Bogota, Colombia Natl Museum Philippines, Manila, Philippines NOVA Univ Lisbon, Caparica, Portugal Royal Saskatchewan Museum, Regina, SK, Canada Deutsch Zentrum Marine Biodiversitatsforsch, Hamburg, Germany Ctr Invest Biol Noroeste, La Paz, Mexico Naturalis Biodivers Ctr, Leiden, Netherlands Univ Douala, Douala, Cameroon Vet & Farmaceut Univ Brno, Brno, Czech Republic Univ Swaziland, Kwaluseni, Eswatini Fundacao Oswaldo Cruz, Rio De Janeiro, Brazil Univ Claude Bernard, Lyon, France Museum Vertebrate Zool, Berkeley, CA USA Smithsonian Inst, Washington, DC 20560 USA Nat Hist Museum & Inst, Chiba, Japan Senckenberg Biodiversitat & Klima Forschunsgzentr, Frankfurt, Germany Marquette Univ, Milwaukee, WI 53233 USA Univ Firenze, Museo Storia Nat, Florence, Italy Univ Fed Bahia, Salvador, BA, Brazil Fed Univ ABC, Sao Bernardo, Brazil Univ Fed Goias, Goiania, Go, Brazil Univ Alaska Museum, Fairbanks, AK USA Egerton Univ, Egerton, Kenya Museo Hist Nat, Lima, Peru IKIAM Univ Reg Amazon, Tena, Ecuador Univ Hyogo, Sanda, Japan Inst Rech Dev, Paris, France Univ Sao Paulo, Piracicaba, Brazil Niedersachs Landesbetrieb Wasserwirtschaft Kusten, Hannover, Germany Univ Complutense Madrid, Madrid, Spain Consejo Nacl Invest Cient & Tecn, Ctr Nacl Patagon, Puerto Madryn, Argentina Roosevelt Univ, Coll Profess Studies, Chicago, IL 60605 USA Western Kentucky Univ, Bowling Green, KY 42101 USA Univ Naples Federico II, Naples, Italy Univ Fed Acre, Rio Branco, Acre, Brazil Univ Fed Santa Catarina, Florianopolis, SC, Brazil Inst Bio & Geociencias Noroeste Argentino, Salta, Argentina Inst Venezolano Invest Cient, Caracas, Venezuela Umweltbundesamt, Vienna, Austria Penclen, Plumelec, France CNRS MNHN UPMC, Ctr Rech Paleobiodivers & Paleoenvironm, Paris, France Staatl Museum Nat Kunde, Stuttgart, Germany Consejo Nacl Invest Cient & Tecn, Museo Argentino Ciencias Nat Bernardino Rivada, Buenos Aires, DF, Argentina Ctr Biol Gest Populat INRA, Montferrier Sur Lez, France Loyola Univ Chicago, Chicago, IL USA Pontificia Univ Catolica Rio do Sul, Porto Alegre, RS, Brazil Durban Museum Nat Sci, Durban, South Africa Univ Estado Amazonas, Manaus, Amazonas, Brazil Brigham Young Univ, Provo, UT 84602 USA Museo Hist Nat La Salle, Caracas, Venezuela Univ Vet Med Hannover, Hannover, Germany Australian Museum, Sydney, NSW, Australia Texas Tech Univ, Lubbock, TX 79409 USA Francis Marion Univ, Florence, SC USA Univ Washington, Seattle, WA 98195 USA Univ Connecticut, Groton, CT USA Fed Univ ABC, Santo Andre, SP, Brazil Univ Fed 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In this study we name and describe a new species of the genus Necromys from northwestern Argentina based on genetic (mtDNA of 77 specimens) and morphologic (assessment of 122 specimens) evidence. Results indicate that the new form is sister species to N. amoenus and highly divergent genetically from all other species of Necromys (≥11.6% divergent). Similarly, the new species presents several unique morphological differences (in skin and skull characters) compared with all other species of the genus and is morphometrically distinct compared with four Argentine taxa. Finally, we assess the lectotype of Necromys conifer, discuss its morphologic similarities with other species of the genus, and argue for maintenance of the generic epithet Necromys. The description of this new species highlights, once again, the continuing need for collecting small mammals and conducting collections-based research. En este estudio nominamos y describimos una nueva especie del género Necromys del noroeste argentino sobre la base de evidencia molecular (DNAmit de 77 especímenes) y morfológica (estudio de 129 especímenes). Los resultados indican que la nueva especie es hermana de N. amoenus y que es genéticamente muy divergente respecto de todas las otras especies de Necromys (divergencia ≥ 11.6%). De igual modo, la nueva especie presenta numerosas diferencias morfológicas (en caracteres de la piel y el cráneo) con todas las otras especies del género, y es morfométricamente distinguible respecto de las 4 especies de Necromys presentes en Argentina. Finalmente, estudiamos el lectotipo de Necromys conifer, discutimos sus similitudes morfológicas con otras especies del género, y proponemos argumentos en favor del uso del epíteto Necromys. La descripción de esta nueva especie enfatiza, una vez más, la necesidad de colectar pequeños mamíferos y realizar estudios basados en colecciones. Fil: Jayat, Jorge Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Chilecito; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; Argentina Fil: D Elía, Guillermo. Universidad Austral de Chile; Chile Fil: Ortiz, Pablo Edmundo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Correlación Geológica. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Departamento de Geología. Cátedra Geología Estructural. Instituto Superior de Correlación Geológica; Argentina Fil: Teta, Pablo Vicente. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina

The tribe Abrotrichini (five genera and 14 living species) is a small clade within the speciose subfamily Sigmodontinae (Rodentia, Cricetidae), representing one of the extant successful radiations of mammals at southern high latitudes of the Neotropics. Its distribution is mostly Andean, reaching its greatest diversity in southern Argentina and Chile. We evaluate the phylogenetic relationships within this tribe through parsimony and Bayesian approaches based on 99 morphological characters (including 19 integumental characters, 38 skull characters, 31 dental characters, three postcranial skeletal characters, seven from the male accessory glands and phallus and one from the digestive system) and six molecular markers (one mitochondrial and five nuclear). We include representatives of all, except one, of the currently recognized species of living Abrotrichini plus one fossil form. Based on total evidence, we recovered a primary division between the genus Abrothrix and a group including the long-clawed Abrotrichini, Chelemys, Geoxus, Notiomys and Pearsonomys. Both clades are recognized and named here as subtribes. The large degree of morphological variation observed within Abrothrix suggests that species in the genus fall into four groups, which we recognize as subgenera. In addition, the two known species of Chelemys do not form a monophyletic group, and Geoxus was recovered as paraphyletic with respect to Pearsonomys. To reconcile classification and phylogenetics, we describe a new genus for Chelemys macronyx and include Pearsonomys as a junior synonym of Geoxus. Our results highlight the importance of both morphology and molecules in resolving the phylogenetic relationships within this tribe. Based on biogeographical analyses, we hypothesize that Abrotrichini originated in south-western South America by vicariance and then diversified mostly by successive dispersal events. Fil: Teta, Pablo Vicente. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Diversidad y Evolución Austral; Argentina Fil: Cañón Valenzuela, Carola Patricia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Diversidad y Evolución Austral; Argentina Fil: Patterson, Bruce. Field Museum of Natural History; Estados Unidos Fil: Pardiñas, Ulises Francisco J.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Diversidad y Evolución Austral; Argentina

Small mammal samples from the archaeological sequence of Cueva Huenul 1 (CH1, 36°56′45″S, 69°47′32″W, Neuquen Province, Argentina) are described, and taphonomic and paleoenvironmental conditions assessed. This site is located near the steppe-monte ecotone in the northernmost Patagonia. Small mammal remains (NISP = 1426, MNE = 1409, MNI = 87) were recovered from Late Pleistocene (13,800–11,800 14 C BP), Early Holocene (9500 14 C BP) and Late Holocene layers (1400 14 C BP). Taphonomic analysis indicates that the CH1 assemblage is an archaeofaunistic owl pellet accumulation. It has a good post-depositional preservation since it was rapidly incorporated in the sedimentary matrix, although it previously experienced trampling action. From latest Pleistocene to Late Holocene, the assemblages are mainly composed by the sigmodontines Eligmodontia spp. and Phyllotis xanthopygus , and the caviomorphs Microcavia australis and Ctenomys sp., suggesting in overall terms a marked ecological stability. CHl is one of the few sites where the Pleistocene–Holocene transition is represented by faunal evidence. The latest Pleistocene sample spanning 13,800 and 11,800 14 C BP indicate scrub steppe with substantial open ground and rocky exposition; one Early Holocene sample (9500 14 C BP) suggests a more heterogeneous environment as evidenced by the first occurrence of Akodon iniscatus and Euneomys chinchilloides . In this context, CH1 assemblages do not reflect the small mammal community reworking that putatively accompanied the Pleistocene–Holocene transition.

Small mammal (Rodentia and Didelphimorphia) remains were recovered from the archaeological site Calera, Pampean region, Buenos Aires Province, Argentina. This site is located in the upper course of the Arroyo Tapalqué, at the western portion of the Tandilia range system. Calera is formed of a series of transgressive features (pits) that were infilled with faunal, lithic, and ceramic materials. The samples studied here are from Pit 2, with radiocarbon dates of 3008 ± 44 BP (bottom), 3005 ± 66 BP (middle) and 2075 ± 44 BP (top). Sigmodontine rodents are diverse, including at least nine species; also recorded were four caviomorph rodents and one didelphid marsupial. Taphonomical analyses suggest that the remains were mainly accumulated by owls and later transported and reworked by water action. The small mammal assemblage of Calera suggests that the environmental conditions at the beginning of the Late Holocene were similar to the present ones, temperate-humid, or perhaps slightly warmer and/or humid. In overall terms, recorded taxa at Calera are indicative of a mosaic of grasslands, flooded terrains and lentic to lotic water bodies. Noteworthy records are those of the sigmodontine rodents Bibimys cf. Bibimys torresi and Pseudoryzomys simplex, both hundreds of kilometers south of their current ranges. The regional extinction of these two mammals over a large area of central-eastern Argentina is perhaps a very recent event, mostly triggered by human impact. Fil: Scheifler, Nahuel Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Investigaciones Arqueológicas y Paleontológicas del Cuaternario Pampeano. Universidad Nacional del Centro de la Provincia de Buenos Aires. Investigaciones Arqueológicas y Paleontológicas del Cuaternario Pampeano; Argentina. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Sociales. Departamento de Arqueología; Argentina Fil: Teta, Pablo Vicente. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina Fil: Pardiñas, Ulises Francisco J.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina