9 research outputs found
First fossil record of the South American frog genus Odontophrynus Reinhardt and Lütken, 1862 (Anura, Neobatrachia)
No full textThe frog genus Odontophrynus comprises 10 species arranged in three species groups that inhabit southeastern South America. In Argentina, it is represented by the O. americanus and O. occidentalis species groups and, despite being a fairly common taxon of the extant herpetofauna, it has no known fossil record. Here we report on the first fossil record of the genus, based on an almost complete right ilium from the lower levels of the Buenos Aires Formation (OIS 11, Bonaerian age, middle Pleistocene) in the Bonaerian Pampas of Argentina. The taxonomic allocation is derived from a thorough survey of anuran ilia and is grounded in a set of distinct ilial characters that, in combination, do not occur in any other anuran. These include: ilium not fused to ischium; well-developed dorsal acetabular expansion; broad preacetabular zone with a shallow preacetabular fossa; straight ilial shaft lacking dorsal ridge; and spike-like dorsal prominence bearing a distinct dorsal protuberance. Additionally, after comparing with a large sample of specimens representing most species of Odontophrynus, we propose two main characters (high spike-like dorsal prominence, absence of a lateral knob on the dorsal prominence) that allow referral to Odontophrynus aff. O. americanus or O. cordobae. SUPPLEMENTAL DATA—Supplemental materials are available for this article for free at www.tandfonline.com/UJVP Citation for this article: Turazzini, G. F., M. L. Taglioretti, and R. O. Gómez. 2016. First fossil record of the South American frog genus Odontophrynus Reinhardt and Lütken, 1862 (Anura, Neobatrachia). Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2017.1228657.Fil: Turazzini, Guillermo Fidel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Geología; ArgentinaFil: Taglioretti, Matias Luciano. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Geología de Costas y del Cuaternario. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto de Geología de Costas y del Cuaternario; ArgentinaFil: Gomez, Raul Orencio. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Geología; Argentin
A reassessment of the taxonomic status of Paraglyptodon Castellanos, 1932 (Mammalia, Cingulata, Glyptodontia)
No full textCastellanos described and published about new genera of glyptodonts, according to a phylogenetic scheme mainly based on the evolution of the external surface of the dorsal carapace. Among these new genera, Castellanos proposed Paraglyptodon as the predecessor of Glyptodon, and included within Paraglyptodon all known species of Glyptodontinae recovered from “horizontes pre-Ensenadenses”, and within Glyptodon all known species from “Horizontes pampeanos”, restricting the latter to the Quaternary. All the species that belong to Paraglyptodon, that is Paraglyptodon chapalmalensis, Paraglyptodon uquiensis, Paraglyptodon dubius, and Paraglyptodon paranensis were established based on one, two or few osteoderms, mostly from the dorsal carapace. Regarding P. paranensis and P. dubius, Oliva and collaborators consider the first as a nomen vanum, representing an indeterminate Glyptodontinae, and the second as a synonym of P. chapalmalensis. Upon re-examination of the holotypes of P. chapalmalensis and P. uquiensis together with their comparison with other well-known specimens of glyptodonts, mainly with Glyptodon (of both juvenile and adult stages), we found the same ornamentation in different sections of the dorsal carapaces, particularly in P. chapalmalensis and in juvenile stages of Glyptodon spp. We could not identify features that would allow us to make a distinction between the holotype of P. uquiensis and Glyptodon spp. Therefore, we consider that a new taxon guide for naming the Upper Chapadmalalan biozone is necessary. The biostratigraphic range of Glyptodon could possibly be extended to the late Pliocene. However, new records and studies are needed to verify the existence of this taxon in the Chapadmalalan Stage/Age in its type locality.Fil: Cruz, Laura Edith. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Fernicola, Juan Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Luján. Departamento de Ciencias Básicas; ArgentinaFil: Taglioretti, Matias Luciano. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Geología de Costas y del Cuaternario. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto de Geología de Costas y del Cuaternario; ArgentinaFil: Toledo, Néstor. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleontología Vertebrados; Argentin
Regarding the real diversity of Glyptodontidae (Mammalia, Xenarthra) in the late Pliocene (Chapadmalalan Age/Stage) of Argentina
No full textABSTRACT A large diversity of Glyptodontidae has been proposed as characterizing the Chapadmalalan Age (Pliocene). Most of these taxa were recognized on the basis of partial dorsal carapaces and/or caudal tubes, whereas the main diagnostic characteristic is a particular morphology of the exposed surface of the osteoderms. From a biostratigraphic point of view some species are biostratigraphically important. The Upper Chapadmalalan is based on the Paraglyptodon chapadmalensis biozone. Both the re-evaluation of the type and referred materials and new significant findings from the Chapadmalal and El Polvorín Formations indicate that the diversity of Pliocene Glyptodontidae is more limited than previously supposed. The particular morphology of the exposed surface of the osteoderms that characterizes some of the species actually corresponds to a taphonomic alteration, which results in a non-real ornamentation pattern. Thus, the Glyptodontinae P. chapadmalensis must be replaced as a fossil guide because neither this species nor the species included in the genera Urotherium, Trachycalyptus and Lomaphorus are well characterized. Taking into account the diversity of Glyptodontidae for this lapse, the Glyptodontinae are very scarce (a situation that contrasts with its records in the Pleistocene), whereas Eosclerocalyptus, "Plohophorini" (Plohophorus) and Doedicurinae (cf. Eleutherocercus antiquus) are among the most recorded taxa
A mitogenomic timetree for Darwins enigmatic South American mammal Macrauchenia patachonica
No full textThe unusual mix of morphological traits displayed by extinct South American native ungulates (SANUs) confounded both Charles Darwin, who first discovered them, and Richard Owen, who tried to resolve their relationships. Here we report an almost complete mitochondrial genome for the litoptern Macrauchenia. Our dated phylogenetic tree places Macrauchenia as sister to Perissodactyla, but close to the radiation of major lineages within Laurasiatheria. This position is consistent with a divergence estimate of -1/466 Ma (95% credibility interval, 56.64-77.83 Ma) obtained for the split between Macrauchenia and other Panperissodactyla. Combined with their morphological distinctiveness, this evidence supports the positioning of Litopterna (possibly in company with other SANU groups) as a separate order within Laurasiatheria. We also show that, when using strict criteria, extinct taxa marked by deep divergence times and a lack of close living relatives may still be amenable to palaeogenomic analysis through iterative mapping against more distant relatives.Fil: Westbury, Michael. Universitat Potsdam; AlemaniaFil: Baleka, Sina. Universitat Potsdam; AlemaniaFil: Barlow, Axel. Universitat Potsdam; AlemaniaFil: Hartmann, Stefanie. Universitat Potsdam; AlemaniaFil: Paijmans, Johanna L.A.. Universitat Potsdam; AlemaniaFil: Kramarz, Alejandro Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; ArgentinaFil: Forasiepi, Analia Marta. 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; ArgentinaFil: Bond, Mariano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleontología Vertebrados; ArgentinaFil: Gelfo, Javier Nicolás. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleontología Vertebrados; ArgentinaFil: Reguero, Marcelo Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleontología Vertebrados; ArgentinaFil: López Mendoza, Patricio Gonzalo. Center for Maritime Archeology Research of the South Eastern Pacific; ChileFil: Taglioretti, Matias Luciano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentina. Provincia de Buenos Aires. Municipalidad de General Pueyrredon. Secretaría de Cultura. Museo Municipal de Ciencias Naturales Lorenzo Scaglia; ArgentinaFil: Scaglia, Fernando. Provincia de Buenos Aires. Municipalidad de General Pueyrredon. Secretaría de Cultura. Museo Municipal de Ciencias Naturales Lorenzo Scaglia; ArgentinaFil: Rinderknecht, Andrés. Museo Nacional de Historia Natural; UruguayFil: Jones, Washington. Museo Nacional de Historia Natural; UruguayFil: Mena, Francisco. Centro de Investigacinn En Ecosistemas de la Patagonia; ChileFil: Billet, Guillaume. Museum National d'Histoire Naturelle; FranciaFil: de Muizon, Christian. Museum National d'Histoire Naturelle; FranciaFil: Aguilar, José Luis. Museo Paleontologico San Pedro; ArgentinaFil: Macphee, Ross Douglas Earle. American Museum of Natural History; Estados UnidosFil: Hofreiter, Michael. Universitat Potsdam; Alemani
A new Mesembriornithinae (Aves, Phorusrhacidae) provides new insights into the phylogeny and sensory capabilities of terror birds
No full text<div><p>ABSTRACT</p><p>Terror birds constitute the most outstanding group of the South American Cenozoic avifauna. Considered as apex predators, their hunting skills have recently been examined, but their diversity is still unresolved. Here we report a new terror bird from the late Pliocene of Argentina, represented by the most complete articulated skeleton of one yet found. Our phylogenetic analysis places this taxon among derived phorusrhacids (Mesembriornithinae). One of the most striking cranial features of the new species is the suppression of intracranial kinesis due to the presence of an independent ossified bone that increases the structural link between the lacrimal and jugal bars, and the absence of both palatal hinges. The new species possesses ossified tracheal rings and a tracheobronchial syrinx, as well as sclerotic ossicles to adjust the shape of the cornea during its diurnal vision, and reveals a mean hearing sensitivity (~2300 Hz) below the average for living species. The discovery of this new species provides new insights for studying the anatomy and phylogeny of phorusrhacids and a better understanding of this group's diversification.</p><p>http://zoobank.org/urn:lsid:zoobank.org:pub:AD022100-8C19-49AD-93B5-BF2BF6D7A695</p><p>SUPPLEMENTAL DATA—Supplemental materials are available for this article for free at www.tandfonline.com/UJVP</p></div
Prefigurative Politics: Perils and Promise
No full textMany recent social movements have been characterised by their commitment to direct democratic decision-making procedures and leaderless, non-hierarchic organizational structures. This political tendency also implies the search for autonomy from existing political institutions and practises. Movements seek instead to embody in the political action itself the social relations, ways of collective decision-making and values that are ultimately desired for the whole society. This prefigurative approach to social change is often criticized for being naiive or marginal. This thesis argues first that this is not the case, but that prefigurative politics is misunderstood due to its differing view on questions of strategy, organisation and ultimately the possibility of fundamental societal change. The dissertation first outlines the often implicit strategy or vision of change underpinning prefigurative politics. It then identifies as the key challenge for prefigurative movements their ability to avoid reproducing oppressive forms of power, ‘power-over.’ This understudied aspect is investigated through extensive ethnographic field research with the unemployed workers movement, MTD Lanús in Buenos Aires, and the Zapatista movement in Mexico. The thesis concludes that it seems impossible to completely avoid reproducing old forms of power. Often key individuals in the movements end up in a paradoxical position whereby, in an effort to ensure the group’s prefigurative nature, these individuals enjoy non-prefigurative influence. The findings imply that the state and corresponding political forms and practise are not the only source of hierarchic pressures. As such, it would be more useful to view prefigurative political action as desirable, yet impossible
New radiometric ⁴⁰Ar–³⁹Ar dates and faunistic analyses refine evolutionary dynamics of Neogene vertebrate assemblages in southern South America
No full textThe vertebrate fossil record of the Pampean Region of Argentina occupies an important place in South American vertebrate paleontology. An abundance of localities has long been the main basis for constructing the chronostratigraphical/geochronological scale for the late Neogene-Quaternary of South America, as well as for understanding major patterns of vertebrate evolution, including the Great American Biotic Interchange. However, few independently-derived dates are available for constraining this record. In this contribution, we present new ⁴⁰Ar/³⁹ dates on escorias (likely the product of meteoric impacts) from the Argentinean Atlantic coast and statistically-based biochronological analyses that help to calibrate Late Miocene-Pliocene Pampean faunal successions. For the type areas of the Montehermosan and Chapadmalalan Ages/Stages, our results delimit their age ranges to 4.7-3.7 Ma and ca. 3.74-3.04 Ma, respectively. Additionally, from Buenos Aires Province, dates of 5.17 Ma and 4.33 Ma were recovered for "Huayquerian" and Montehermosan faunas. This information helps to better calibrate important first appearances of allochthonous taxa in South America, including one of the oldest records for procyonids (7.24-5.95 Ma), cricetids (6.95-5.46 Ma), and tayassuids (> 3.74 Ma, oldest high-confidence record). These results also constrain to ca. 3 Ma the last appearances of the autochthonous sparassodonts, as well as terror birds of large/middle body size in South America. South American faunal turnover during the late Neogene, including Late Pliocene extinctions, is interpreted as a consequence of knock-on effects from global climatic changes and initiation of the icehouse climate regime.Facultad de Ciencias Naturales y Muse
Palaeoproteomics resolves sloth relationships
No full textThe living tree sloths Choloepus and Bradypus are the only remaining members of Folivora, a major xenarthran radiation that occupied a wide range of habitats in many parts of the western hemisphere during the Cenozoic, including both continents and the West Indies. Ancient DNA evidence has played only a minor role in folivoran systematics, as most sloths lived in places not conducive to genomic preservation. Here we utilize collagen sequence information, both separately and in combination with published mitochondrial DNA evidence, to assess the relationships of tree sloths and their extinct relatives. Results from phylogenetic analysis of these datasets differ substantially from morphology-based concepts: Choloepus groups with Mylodontidae, not Megalonychidae; Bradypus and Megalonyx pair together as megatherioids, while monophyletic Antillean sloths may be sister to all other folivorans. Divergence estimates are consistent with fossil evidence for mid-Cenozoic presence of sloths in the West Indies and an early Miocene radiation in South America
Los retos de la investigación de la zooarqueología en Colombia: una visión preliminar
No full textIn Colombia, zooarchaeology faces numerous challenges due to limited preparation and resources, particularly in the field of preventive archaeology. This discipline—integrating zoology, biology, ecology, geology, history, and anthropology—has evolved from being practiced primarily by palaeontologists, veterinarians, and biologists to becoming part of New Archaeology through the work of anthropologists and archaeologists. However, recent advances in genetic analysis and spectrometry have challenged traditional methods and underscored existing inequalities in access to these tools. In Colombia, zooarchaeological research has been concentrated in the Atlantic Coast and the Bogotá Savannah regions but is hindered by the lack of publicly accessible reference collections and insufficient academic training in the field. A recent survey reveals the urgent need to improve zooarchaeological education, promote the adoption of new approaches and methodologies, and address disparities in access to advanced technologies. The incorporation of techniques such as ancient DNA analysis, morphometrics, proteomics, and stable isotope analysis has transformed the study of animal remains in archaeological contexts. To strengthen the discipline, it is essential to enhance training, resources, and institutional support, and to ensure access to reference collections—both physical and digital—within preventive archaeology practices. In conclusion, zooarchaeology in Colombia holds great potential for development, and the active involvement of the State is crucial to meet contemporary challenges related to sustainability and environmental change.En Colombia, la zooarqueología enfrenta diversos retos debido a la falta de preparación y recursos, especialmente en arqueología preventiva. La disciplina, que integra zoología, biología, ecología, geología, historia y antropología, ha evolucionado desde sus inicios, pasando de ser practicada por paleontólogos, veterinarios y biólogos, a ser integrada en la Nueva Arqueología por antropólogos y arqueólogos. Sin embargo, los avances recientes en análisis genético y espectrometría cuestionan los métodos tradicionales y destacan las desigualdades en el acceso a estos recursos. En Colombia, la investigación zooarqueológica se ha concentrado en la Costa Atlántica y la Sabana de Bogotá, pero enfrenta dificultades debido a la falta de colecciones de referencia de acceso público y la insuficiente formación en esta disciplina en las universidades. La encuesta realizada revela la necesidad de mejorar la formación de los zooarqueólogos, fomentar la adaptación a nuevos enfoques y metodologías, y abordar las desigualdades en el acceso a recursos y metodologías avanzadas. La incorporación de técnicas como el análisis de ADN antiguo, la morfometría, la proteómica y el análisis de isótopos estables ha transformado el estudio de los restos animales en contextos arqueológicos. Para fortalecer la disciplina, es crucial mejorar la formación, los recursos y el apoyo institucional, así como facilitar el acceso a colecciones de referencia en actividades de arqueología preventiva, ya sea en medios físicos o digitales. En resumen, la zooarqueología en Colombia tiene un gran potencial por desarrollar, y se requiere la participación del Estado para enfrentar los desafíos contemporáneos de sostenibilidad y cambio ambiental
