Documentación asociada a un fósil, registro que recupera la historia en las colecciones.

La documentación asociada al fósil de una colección se vincula entre sí y al ejemplar por medio del número de catálogo. La desvinculación entre la pieza y toda su información conlleva la pérdida o la disminución de su valor científico. El traslado de piezas, dentro o fuera de la institución, es un paso crítico para esta asociación. Escasos establecimientos conservan la documentación administrativa de las colecciones. Ante estas situaciones y el paso del tiempo, pueden aparecer dudas sobre los datos originales de algunas piezas, lo cual puede motivar reclamos. En 1998, previo a la Ley N° 25.743 de Protección del Patrimonio Arqueológico y Paleontológico, ocurrió un intercambio epistolar entre el Museo Argentino de Ciencias Naturales Bernardino Rivadavia (MACN) de la ciudad de Buenos Aires y el Museo Municipal de Ciencias Naturales Lorenzo Scaglia de Mar del Plata, con motivo de la restitución de un ejemplar fósil del género Abrocoma (Mammalia, Rodentia). Este evento surgió a raíz de varias situaciones donde predominaron la trasmisión oral de la información y la memoria. Esto desencadenó una discusión sobre dónde debía quedar alojado el material (colectado en el partido de General Pueyrredón, provincia de Buenos Aires). La resolución del conflicto quedó registrada en una serie de cartas que ambas instituciones conservan, gracias a lo cual pudo reconstruirse la historia del material.Fil: Alvarez, Stella Maris. Universidad Maimónides; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fundación de Historia Natural Félix de Azara; ArgentinaFil: Taglioretti, Matias Luciano. 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: Chornogubsky, L.. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina34º Jornadas Argentinas de Paleontología de VertebradosMendozaArgentinaUniversidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y CienciasMuseo Argentino de Ciencias Naturales "Bernardino RivadaviaMuseo de Historia Natural de San Rafae

New Early Eocene mammalian fauna from western Patagonia, Argentina

Two new fossil mammal localities from the Paleogene of central-western Patagonia are preliminarily described as the basis for a new possible biochronological unit for the early Eocene of Patagonia, correlated as being between two conventional SALMAs, the Riochican (older) and the Vacan subage of the Casamayoran SALMA. The mammal-bearing strata belong to the Middle Chubut River Volcanic-Pyroclastic Complex (northwestern Chubut Province, Argentina), of Paleocene-Eocene age. This complex includes a variety of volcaniclastic, intrusive, pyroclastic, and extrusive rocks deposited after the K-T boundary. Geochronological data taken from nearby volcanic deposits that underlie and overlie the mammal-bearing levels indicate that both faunas are of late early Eocene age (Ypresian-Lutetian boundary). In addition to more than 50 species of mammals, including marsupials, ungulates, and xenarthrans, two lower molars are the oldest evidence of bats in South America. Paleobotanical and palynological evidence from inferred contemporary localities nearby indicate subtropical environments characterized by warm and probably moderately humid climate. Remarkably, this new fauna is tentatively correlated with Eocene mammals from the La Meseta Formation in the Antarctic Peninsula. We conclude that the two localities mentioned above are part of a possible new biochronological unit, but the formal proposal of a new SALMA awaits completion of taxonomic analysis of the materials reported upon here. If the La Meseta fauna is correlated biochronologically to western Patagonia, this also suggests a continental extension of the biogeographic Weddelian Province as far north as central-western Patagonia

The skull of Epidolops ameghinoi from the early Eocene Itaboraí fauna, southeastern Brazil, and the affinities of the extinct marsupialiform order Polydolopimorphia

The skull of the polydolopimorphian marsupialiform Epidolops ameghinoi is described in detail for the first time, based on a single well-preserved cranium and associated left and right dentaries plus additional craniodental fragments, all from the early Eocene (53-50 million year old) Itaboraí fauna in southeastern Brazil. Notable craniodental features of E. ameghinoi include absence of a masseteric process, very small maxillopalatine fenestrae, a prominent pterygoid fossa enclosed laterally by a prominent ectopterygoid crest, an absent or tiny transverse canal foramen, a simple, planar glenoid fossa, and a postglenoid foramen that is immediately posterior to the postglenoid process. Most strikingly, the floor of the hypotympanic sinus was apparently unossified, a feature found in several stem marsupials but absent in all known crown marsupials. "Type II" marsupialiform petrosals previously described from Itaboraí plausibly belong to E. ameghinoi; in published phylogenetic analyses, these petrosals fell outside (crown-clade) Marsupialia. "IMG VII" tarsals previously referred to E. ameghinoi do not share obvious synapomorphies with any crown marsupial clade, nor do they resemble those of the only other putative polydolopimorphians represented by tarsal remains, namely the argyrolagids. Most studies have placed Polydolopimorphia within Marsupialia, related to either Paucituberculata, or to Microbiotheria and Diprotodontia. However, diprotodonty almost certainly evolved independently in polydolopimorphians, paucituberculatans and diprotodontians, and Epidolops does not share obvious synapomorphies with any marsupial order. Epidolops is dentally specialized, but several morphological features appear to be more plesiomorphic than any crown marsupial. It seems likely Epidolops that falls outside Marsupialia, as do morphologically similar forms such as Bonapartherium and polydolopids. Argyrolagids differ markedly in their known morphology from Epidolops but share some potential apomorphies with paucituberculatans. It is proposed that Polydolopimorphia as currently recognised is polyphyletic, and that argyrolagids (and possibly other taxa currently included in Argyrolagoidea, such as groeberiids and patagoniids) are members of Paucituberculata. This hypothesis is supported by Bayesian non-clock phylogenetic analyses of a total evidence matrix comprising DNA sequence data from five nuclear protein-coding genes, indels, retroposon insertions and morphological characters: Epidolops falls outside Marsupialia, whereas argyrolagids form a clade with the paucituberculatans Caenolestes and Palaeothentes, regardless of whether the Type II petrosals and IMG VII tarsals are used to score characters for Epidolops or not. There is no clear evidence for the presence of crown marsupials at Itaboraí, and it is possible that the origin and early evolution of Marsupialia was restricted to the "Austral Kingdom" (southern South America, Antarctica, and Australia)

A review of the molar morphology and phylogenetic affinities of Sillustania quechuense (Metatheria, Polydolopimorphia, Sillustaniidae), from the early Paleogene of Laguna Umayo, southeastern Peru

The early Paleogene mammalian assemblages known from the red mudstones of the Lower Muñani Formation at Laguna Umayo, southeastern Perú, add significant information on the early phases of the evolution of Metatheria in South America. Two early Cenozoic vertebrate associations have been found from the Laguna Umayo area: localities LU-3 and Chulpas, both including metatherians. The Chulpas local fauna includes at least three indeterminate didelphimorphians and three polydolopimorphians: Chulpasia mattaueri, Chulpasia jimthorselli, and Sillustania quechuense (Sillustanidae). The Laguna Umayo associations have alternatively been referred to the Late Cretaceous or the early Paleogene. The highly derived, enigmatic morphology of the only known upper molar of Sillustania quechuense granted the recognition of a new family of South American metatherians: Sillustaniidae. Crochet and Sigé (1993) preliminary assumed that Sillustania was probably a caenolestoid paucituberculatan, but in their formal description they recognized the Sillustaniidae as a new family belonging to the polydolopoid polydolopimorphians. A review of the holotype and tentatively referred specimen of Sillustania quechuense led us to reassess its upper molar morphology and homologies, as well as its phylogenetic affinities. The discussion of these aspects constitutes the main purpose of this work.Fil: Chornogubsky Clerici, Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales ; ArgentinaFil: Goin, Francisco Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales ; Argentin

Notonuphar antarctica, an extinct water lily (Nymphaeales) from the Eocene of Antarctica

A new genus and species, Notonuphar antarctica, is described from the Eocene of Seymour (Marambio) Island, the Antarctic Peninsula and assigned to the Nymphaeales based on well-preserved seeds. This is the first record of a water lily from Antarctica and the first record of a Gondwanan plant with close link to the genus Nuphar (Nymphaeaceae), which is restricted today to the Northern Hemisphere. Critical features for systematic placement of Notonuphar are the presence of a germination cap with closely spaced hilar scar and micropyle, anatropous, bitegmic and exotestal seed organization, exotesta composed of one cell layer of high sclerenchymatic palisade-shape cells, mesotesta of smaller, low parenchymatic cells, a few cell layers deep, and a thin tegmen. The seeds of Notonuphar are particularly similar to seeds of extant and fossil Nuphar in the straight, unfolded anticlinal wall of the exotestal cells and the presence of a narrow zone of exotestal tissue between hilum and micropyle. Other seed features including the very tall exotestal cells and strongly thickened cell walls of exotesta also link Notonuphar to Brasenia and related fossil taxa (Cabombaceae). This character mosaic observed in Notonuphar corroborates the transitional position of Nuphar between Cabombaceae and Nymphaeaceae. Notonuphar is the only member of Nymphaeales recorded from Antarctica and so far the only fossil seeds of Nymphaeales known from the Southern Hemisphere. The discovery of this extinct Gondwanan taxon with features suggesting close relationship with extant Northern Hemisphere genus Nuphar is a further evidence for the relictual nature of the extant group.Other funding from:Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET Grant PIP 0462 to MAR.), the Argentine National Agency for Promotion of Science and Technology (ANPCyT Grant PICTO-2010–0093 to MAR) and the Paul Scherrer Institute https://www.psi.ch/useroffice/useroffice (projects 20130185, 20141047, 2016140)</p