Sitios de Interés Geológico de la República Argentina

Fil: Voglino, Damián. Fundación Óga; Argentina.Las barrancas del río Paraná en la provincia de Buenos Aires representan un extenso escalón en la llanura pampeana que ha atraído el interés de naturalistas (fundamentalmente geólogos y paleontólogos) entre mediados del siglo XIX y principios del XX. Llamativamente, los estudios sobre ellas cesaron abruptamente por un largo período, para ser retomados en épocas muy recientes. Por el contrario, sus características estructurales y biológicas cautivaron a sus habitantes desde los inicios de la época colonial, modelándose en ellos una identidad influenciada por estas geoformas. En este sentido, constituyen reservorios del patrimonio natural y cultural de la región. Sin embargo, de seguir el ritmo que impone el actual desarrollo industrial y urbano, gran parte de sus perfiles naturales y sus comunidades biológicas nativas asociadas corren el riesgo de ser eliminadas en las próximas décadas

Interrelationship between ectoparasites and wild rodents from northeastern Buenos Aires province, Argentina

Infestation parameters and indices of mites, ticks and fleas associated with wild rodents from northeastern Buenos Aires Province, Argentina, were studied. Host species similarity was also analyzed in relation to their ectoparasites. Fifty-five rodents were captured from January 2000 to March 2001. In total, 1,022 ectoparasites were collected and three ectoparasite-host associations were new records. However, this is the first study on Craneopsylla minerva wolffhuegeli infesting parameters. Ectoparasite total mean abundance and total prevalence were higher in Holochilus brasiliensis (MA = 47.7; P = 100%) and Scapteromys aquaticus (MA = 25.4; P = 95.4%), meanwhile specific richness and diversity were higher in Oligoryzomys flavescens (S = 6; H = 1.3) and Akodon azarae (S = 4; H = 1.0). On the other hand, the only individual of Calomys laucha was not parasited. S. aquaticus-H. brasiliensis, which preferred similar microhabitats, shared the same ectoparasite species (Css = 100). Whereas, A. azarae, which was mostly associated with grassland, showed the highest difference with the other hosts (Css < 0.4). Considering every ectoparasite species, H. brasiliensis showed the highest mean abundance, prevalence and preference. The results suggest that the particular characteristics of this rodent would give it better possibilities not only of being infested by ectoparasites, but also of transmitting them to its progeny.Facultad de Ciencias Naturales y Muse

Sigmodontine rodents (mammalia: rodentia: cricetidae) and other micromammals from Northern Buenos Aires province (Argentina) : paleoenvironmental reconstruction for the uppermost Ensenadan

Se estudiaron aspectos taxonómicos y paleoambientales de un agregado de micromamíferos coleccionado en sedimentos pleistocénicos de Ramallo (33° 29’ S, 60° 01’ O, partido de Ramallo, provincia de Buenos Aires). Los sedimentos portadores pueden referirse a la parte superior de la Formación Ensenada (Piso Ensenadense, Biozona de Tolypeutes pampaeus) con una edad algo más joven que 0,78 Ma. Se registraron los siguientes roedores Sigmodontinae: Akodon cf. A. azarae (Fisch.), Necromys cf. N. benefactus (Thos.), Scapteromys cf. S. aquaticus-S. tumidus, Oligoryzomys cf. O. flavescens (Waterh.), Calomys cf. C. laucha-C. musculinus, Graomys cf. G. griseoflavus (Waterh.), Reithrodon auritus (Fisch.) y un género indeterminado. La composición taxonómica del agregado de Ramallo robustece la hipótesis que la estructura específica de las comunidades vivientes de sigmodontinos se alcanza, en la región pampeana, durante el Ensenadense. Un análisis integral de las evidencias paleobiológicas del perfil de Ramallo indica la transición entre condiciones cálidas y húmedas hacia otras frías y secas. Las primeras son sugeridas por el desarrollo de una comunidad característica de bosques de Celtis tala Gill. ex Planch. similar a la que se verifica actualmente en Ramallo. Condiciones frías y secas son evidenciadas por el registro de marmosinos y roedores extralocales de afinidades centrales y patagónicas (e.g., Lestodelphys sp., Microcavia sp.) y la ausencia de C. tala. Este cambio climático se verifica por arriba del límite Matuyama-Brunhes, indicando un desacople entre la reversión paleomagnética y el deterioro ambiental en el norte de la provincia de Buenos Aires.We studied taxonomical and paleoenvironmental aspects of a micromammal assemblage recovered from Pleistocene sediments in Ramallo (33° 29’ S, 60° 01’ W, Ramallo county, Buenos Aires province). The bearing sediments can be referred to the uppermost part of the Ensenada Formation (Ensenadan Stage, Biozone of Tolypeutes pampaeus) aged little younger than 0.78 Ma. The following sigmodontine rodents were recorded: Akodon cf. A. azarae (Fisch.), Necromys cf. N. benefactus (Thos.), Scapteromys cf. S. aquaticus-S. tumidus, Oligoryzomys cf. O. flavescens (Waterh.), Calomys cf. C. laucha-C. musculinus, Graomys cf. G. griseoflavus (Waterh.), Reithrodon auritus (Fisch.), and an unidentified genus. The Ramallo assemblage supports the hypothesis that the specific structure of modern sigmodontine fauna in Buenos Aires province was settled during the Ensenadan. An integral analysis including all the biotic evidences collected in the Ramallo section (rodents, marsupials, plant macrofossils, mollusks, and insects) indicates a transition from wet and warm conditions to dry and cold ones. The former conditions are suggested by the development of a Celtis tala Gill. ex Planch. wood, similar to those presently occurring in Ramallo area. The latter conditions are evidenced by the record of extralocal Central-Patagonian marmosines and rodents (e.g., Lestodelphys sp., Microcavia sp.) and the absence of C. tala. This environmental and climatic change took place above the Matuyama-Brunhes boundary, at the end of the Ensenadan stage, indicating a delay between the paleomagnetic reversion and the environmental deterioration in northeastern Buenos Aires province.IGMODONTINE RODENTS (MAMMALIA: RODENTIA: CRICETIDAE) AND OTHER MICROMAMMALS FROM NORTHERNBUENOS AIRES PROVINCE (ARGENTINA): PALEOENVIRONMENTAL RECONSTRUCTION FOR THE UPPERMOST ENSENADAN. We studied taxonomical and paleoenvironmental aspects of a micromammal assemblage recovered from Pleistocene sediments in Ramallo (33° 29’ S, 60° 01’ W, Ramallo county, Buenos Aires province). The bearing sediments can be referred to the uppermost part of the Ensenada Formation (Ensenadan Stage, Biozone of Tolypeutes pampaeus) aged little younger than 0.78 Ma. The following sigmodontine rodents were recorded: Akodon cf. A. azarae (Fisch.), Necromys cf. N. benefactus (Thos.), Scapteromys cf. S. aquaticus-S. tumidus, Oligoryzomys cf. O. flavescens (Waterh.), Calomys cf. C. laucha-C. musculinus, Graomys cf. G. griseoflavus (Waterh.), Reithrodon auritus (Fisch.), and an unidentified genus. The Ramallo assemblage supports the hypothesis that the specific structure of modern sigmodontine fauna in Buenos Aires province was settled during the Ensenadan. An integral analysis including all the biotic evidences collected in the Ramallo section (rodents, marsupials, plant macrofossils, mollusks, and insects) indicates a transition from wet and warm conditions to dry and cold ones. The former conditions are suggested by the development of a Celtis tala Gill. ex Planch. wood, similar to those presently occurring in Ramallo area. The latter conditions are evidenced by the record of extralocal Central-Patagonian marmosines and rodents (e.g., Lestodelphys sp., Microcavia sp.) and the absence of C. tala. This environmental and climatic change took place above the Matuyama-Brunhes boundary, at the end of the Ensenadan stage, indicating a delay between the paleomagnetic reversion and the environmental deterioration in northeastern Buenos Aires province.Fil: Voglino, Damián. Universidad Nacional de La Plata; ArgentinaFil: Pardiñas, Ulises Francisco J.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; Argentin

Carnivoran fossils from the Pampean region (Argentina): Santiago Roth collections in Switzerland

Santiago Roth (1850–1924) was a naturalist that collected and sold fossils from the Pampean region (Argentina) in Europe. Much of the specimens collected by Roth are hosted at the Paläontologisches Institut und Museum, Universität Zürich and Muséun D’Histoire Naturelle of Geneva in Switzerland, but were never studied. In this article, we review the specimens of the order Carnivora under a taxonomical and temporal approach. We confirm the presence of 16 specimens of Carnivora collected by Roth between the provinces of Santa Fe and Buenos Aires. We identify felids (Smilodon sp., Panthera onca, and specimens related to these taxa), ursids (Arctotherium sp.), and canids (Dusicyon avus and specimens related, Lycalopex sp., and Caninae indet.). According to the information reported by S. Roth, all materials are from the Pleistocene of the Pampean Formation. However, given the scarcity of data, only the specific age of few specimens could be more accurately established

Of the silmarils and the ring: J. R. R. Tolkien\u27s fiction and the importance of creation and art

J. R. R. Tolkien embodies the opposing ideals of Enchantment and the Machine in the Silmarils and the One Ring respectively. These created objects oppose each other just as Tolkien’s ideals of art do. Enchantment is art’s ideal, it\u27s purpose is to glorify and enrich the beauty of reality through subcreation. The Silmarils exhibit the delight of making and perceiving beauty. Whereas the Machine is art’s shadowy reflection that utilizes apparatuses or devices rather than personal talent in order to coerce others and reality itself. Overall Tolkien\u27s aesthetic theories reflect many fears surrounding modern attitudes toward weaponizing art. Tolkien supplies Enchantment as the solution to these problems surrounding art and creativity in an oppressively technological world

Un nuevo Notungulado Hipsodonte (Hegetotheriidae, Pachyrukhinae) del Mioceno tardío de la Cordillera Oriental, provincia de Salta, Noroeste de Argentina

Late Miocene fluvial strata of the Palo Pintado Formation are broadly exposed to the northwest of the town of Angastaco, Salta province, Northwest of Argentina. These strata accumulated in the extensional Angastaco Basin. Recent field work at the Palo Pintado Formation (late Miocene), Valle Calchaquí, Salta province, Argentina has provided fossil remains that greatly increased the knowledge of the faunal assemblage of this site. A number of notoungulates and rodents were collected. A partial left jaw was collected at Quebrada Peñas Blancas along the west bank of the Río Calchaquí. Morphological and morphometric comparisons permit referral of this specimen to a new species of hegetotheriid notoungulate Paedotherium kakai sp. nov. It represents the first report of Paedotherium for the Eastern Cordillera and one of the few well-documented occurrences of this genus outside of middle-high latitudes Argentina. The widespread geographic range of Paedotherium, combined with its restricted temporal range, suggest it may be one of the most useful biostratigraphic indicator taxa for Neogene faunas. Paedotherium kakai would have been a mixed feeder that lived in gallery forests, feeding close to water bodies of a system river and lagoons, in food plains developed under humid and subtropical climate.Los estratos fluviales asignados al Mioceno tardío de la Formación Palo Pintado están ampliamente expuestos al noroeste de la localidad Angastaco, provincia de Salta, noroeste de Argentina. Estos estratos fueron acumulados en la Cuenca de Angastaco. Recientes trabajos de campo en la Formación Palo Pintado (Mioceno tardío), Valle Calchaquí, provincia de Salta, Argentina ha provisto restos fósiles que han incrementado el conocimiento de la asociación faunística de ese sitio. Un número discreto de especímenes (notoungulados y roedores) fueron colectados. Una porción de cuerpo mandibular izquierdo fue colectado en la localidad Quebrada Peñas Blancas a lo largo del margen oeste del río Calchaquí. Comparaciones morfológicas permiten referir a este espécimen a una nueva especie de notoungulado hegetotérido, Paedotherium kakai sp. nov. Esta nueva especie representa el primer registro de Paedotherium para la Cordillera Oriental y una de las pocas bien documentadas ocurrencias de este género fuera de las latitudes medias y altas de Argentina. El amplio rango de registro geográfico de Paedotherium, combinado con su restringido rango temporal sugiere que este género puede considerarse como un buen indicador bioestratigráfico para las faunas del Neógeno. Paedotherium kakai puede ser considerado un ‘mixed feeder’ que vivió en bosques, en galerías, alimentándose en las proximidades de los cuerpos de agua de un río, lagunas o en planicies de inundación bajo un clima húmedo y subtropical.Facultad de Ciencias Naturales y Muse

Un nuevo Notungulado Hipsodonte (Hegetotheriidae, Pachyrukhinae) del Mioceno tardío de la Cordillera Oriental, provincia de Salta, Noroeste de Argentina

Late Miocene fluvial strata of the Palo Pintado Formation are broadly exposed to the northwest of the town of Angastaco, Salta province, Northwest of Argentina. These strata accumulated in the extensional Angastaco Basin. Recent field work at the Palo Pintado Formation (late Miocene), Valle Calchaquí, Salta province, Argentina has provided fossil remains that greatly increased the knowledge of the faunal assemblage of this site. A number of notoungulates and rodents were collected. A partial left jaw was collected at Quebrada Peñas Blancas along the west bank of the Río Calchaquí. Morphological and morphometric comparisons permit referral of this specimen to a new species of hegetotheriid notoungulate Paedotherium kakai sp. nov. It represents the first report of Paedotherium for the Eastern Cordillera and one of the few well-documented occurrences of this genus outside of middle-high latitudes Argentina. The widespread geographic range of Paedotherium, combined with its restricted temporal range, suggest it may be one of the most useful biostratigraphic indicator taxa for Neogene faunas. Paedotherium kakai would have been a mixed feeder that lived in gallery forests, feeding close to water bodies of a system river and lagoons, in food plains developed under humid and subtropical climate.Los estratos fluviales asignados al Mioceno tardío de la Formación Palo Pintado están ampliamente expuestos al noroeste de la localidad Angastaco, provincia de Salta, noroeste de Argentina. Estos estratos fueron acumulados en la Cuenca de Angastaco. Recientes trabajos de campo en la Formación Palo Pintado (Mioceno tardío), Valle Calchaquí, provincia de Salta, Argentina ha provisto restos fósiles que han incrementado el conocimiento de la asociación faunística de ese sitio. Un número discreto de especímenes (notoungulados y roedores) fueron colectados. Una porción de cuerpo mandibular izquierdo fue colectado en la localidad Quebrada Peñas Blancas a lo largo del margen oeste del río Calchaquí. Comparaciones morfológicas permiten referir a este espécimen a una nueva especie de notoungulado hegetotérido, Paedotherium kakai sp. nov. Esta nueva especie representa el primer registro de Paedotherium para la Cordillera Oriental y una de las pocas bien documentadas ocurrencias de este género fuera de las latitudes medias y altas de Argentina. El amplio rango de registro geográfico de Paedotherium, combinado con su restringido rango temporal sugiere que este género puede considerarse como un buen indicador bioestratigráfico para las faunas del Neógeno. Paedotherium kakai puede ser considerado un ‘mixed feeder’ que vivió en bosques, en galerías, alimentándose en las proximidades de los cuerpos de agua de un río, lagunas o en planicies de inundación bajo un clima húmedo y subtropical.Facultad de Ciencias Naturales y Muse

Disentangling the complex alpha taxonomy of Andean populations of Ctenomys (Rodentia: Ctenomyidae) from northern Patagonia: The need for extensive sampling in heterogeneous landscapes

In the Andean portion of northern Patagonia, populations of Ctenomys are found from low-elevation plains to high-elevation meadows and valleys. Despite their prevalence, the taxonomy of these subterranean rodents remains poorly resolved. Using genetic and morphological data obtained from museum specimens and animals collected in the field, we examined the taxonomy of Ctenomys from southwestern Mendoza Province, Argentina. Our analyses suggest the presence of at least five species of Ctenomys within the study area. The highest, innermost portion of the Andes is occupied by C. maulinus. To the east, the mountains and foothills are inhabited by two forms associated with the "mendocinus"and the "magellanicus"lineages, respectively. The former appears to be a local variant of C. emilianus, while the latter is sister to C. pontifex. Although C. pontifex was not encountered during our field sampling, it remains a valid species that likely is restricted to the isolated Valle Hermoso in westernmost Mendoza Province. In addition, we report an undescribed form from Las Leñas Valley that is associated with the "mendocinus"lineage. This complex alpha taxonomic scenario occurs within less than one degree of latitude, thereby highlighting the need to conduct detailed field collections to improve our knowledge of the systematics of Ctenomys.Fil: Tammone, Mauro Nicolás. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Lacey, Eileen A.. University of California at Berkeley; Estados UnidosFil: Voglino, Damián. Museo de Ciencias Naturales Antonio Scasso; ArgentinaFil: Cuéllar Soto, Erika. Sultan Qaboos University; OmánFil: Pardiñas, Ulises Francisco J.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Diversidad y Evolución Austral; Argentin

Pampean megamammals in Europe: the fossil collections from Santiago Roth

Santiago Roth was a Swiss fossil finder, naturalist, and paleontologist that emigrated to Argentina in 1866. His work largely influenced the discipline in the country at the end of the twentieth century, particularly the stratigraphy of the Pampean region. Some of his collections of Pampean fossils were sold to museums and private collectors in Europe and were accompanied by elaborated catalogues. Fossils in the Roth’s catalogues N° 2 and 3 are housed today in the Natural History Museum of Denmark, fossils from catalogues N° 4 to 6, were sold to Swiss museums, with Catalogue N° 5 currently housed at the Department of Paleontology, Universität Zürich. Here, we provide a general framework on the stratigraphy from the Roth’s Pampean fossil sites, summarize the history of the Pampean fossils in Europe originally collected by Roth, and provide historical and curatorial details of the Roth’s collection at the Department of Paleontology, Universität Zürich

Registro más austral de Deltamys kempi (Rodentia, Cricetidae) en Argentina: evidencia paleontológica y neontológica para evaluar su distribución

We report the southernmost locality for the sigmodontine rodent Deltamys kempi Thomas, 1917, in Arroyo Las Tijeras (36°22’43” S, 56°50’12” W, General Lavalle county) near the coast of Buenos Aires province (Argentina), extending the range of the species ca. 150 km S. This record is a wake-up call about the presence of Brazilian fauna well beyond their southernmost suspected limit. Several lines of evidence point to considering D. kempi as a very recent immigrant in Argentina.Reportamos la localidad más austral para el roedor sigmodontino Deltamys kempi Thomas, 1917: Arroyo Las Tijeras (36°22’43” S, 56°50’12” W, Partido de General Lavalle), cerca de la costa de la Provincia de Buenos Aires (Argentina), extendiendo el rango geográ co de la especie ca. 150 km hacia el sur. Este registro constituye una llamada de alerta acerca de la presencia de fauna brasílica bastante más al sur que lo sospechado. Varias líneas de evidencia indican que D. kempi puede ser un inmigrante muy reciente en la fauna Argentina.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; ArgentinaFil: de Los Reyes, Leonardo Martín. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; ArgentinaFil: Voglino, Damián. Museo de Ciencias Naturales Antonio Scasso; ArgentinaFil: Galliari, Carlos Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Estudios Parasitológicos y de Vectores. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios Parasitológicos y de Vectores; Argentin