Cretaceous Small Scavengers: Feeding Traces in Tetrapod Bones from Patagonia, Argentina

Ecological relationships among fossil vertebrate groups are interpreted based on evidence of modification features and paleopathologies on fossil bones. Here we describe an ichnological assemblage composed of trace fossils on reptile bones, mainly sphenodontids, crocodyliforms and maniraptoran theropods. They all come from La Buitrera, an early Late Cretaceous locality in the Candeleros Formation of northwestern Patagonia, Argentina. This locality is significant because of the abundance of small to medium-sized vertebrates. The abundant ichnological record includes traces on bones, most of them attributable to tetrapods. These latter traces include tooth marks that provde evidence of feeding activities made during the sub-aerial exposure of tetrapod carcasses. Other traces are attributable to arthropods or roots. The totality of evidence provides an uncommon insight into paleoecological aspects of a Late Cretaceous southern ecosystem

A new pterosaur tarcksite from the Upper Cretaceous Candeleros Formation, Neuquén Province, Patagonia, Argentina

New pterosaur tracks from the Aguada de Tuco tracksite of the Cenomanian Candeleros Formation (Neuquén Basin, Argentina) are reported here. They are preserved in medium grain-sized sandstones from fluvial deposits and are associated with Arenicolites isp. The pterosaur tracks are preserved as concave and convex epirelief, as true tracks and natural casts, respectively. The manus impressions, which are the most abundant, are usually isolated, although manus-pes sets and sequences of manus-manus imprints, some of them probably representing trackways, have been also documented. The best-preserved manus tracks (average 10.8 cm long, 5.4 cm wide) are tridactyl and strongly asymmetrical. The pes tracks (average 11.5 cm long, 4.8 cm wide) are very elongated, trapezoidal to subtriangular, and generally preserve three-digit impressions. Some morphological track variabilities, such as elongated impressions of manus digit III, has been interpreted as the result of variations in substrate properties, mainly moisture content, and behavior. The main features of the studied tracks, manus and pes track morphologies and length/width ratios, are similar to those of the Pteraichnus ichnogenus. Nevertheless, due to their preservation, not optimal, we classify them as cf. Pteraichnus isp. Only other site with pterosaur tracks has been found in the early Late Cretaceous of South America. These tracks are also in the Candeleros Formation but differ from the Aguada de Tuco ones in having differences in divarication of manus digit impressions, among other features. The present study contributes to the knowledge of the poorly pterosaur track record from Gondwana and its ichnotaxonomic and paleoecological implications.Fil: Heredia, Arturo Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; ArgentinaFil: Díaz Martínez, Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigación en Paleobiología y Geología; ArgentinaFil: Pazos, Pablo Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; ArgentinaFil: de Valais, Silvina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigación en Paleobiología y Geología; ArgentinaXII Congreso de la Asociación Paleontológica ArgentinaBuenos AiresArgentinaAsociación Paleontológica Argentin

Triassic pentadactyl tracks from the Los Menucos Group (Río Negro province, Patagonia Argentina): Possible constraints on the autopodial posture of Gondwanan trackmakers

The Los Menucos locality in Patagonia, Argentina, bears a well-known ichnofauna mostly documented by small therapsid footprints. Within this ichnofauna, large pentadactyl footprints are also represented but to date were relatively underinvestigated. These footprints are here analyzed and discussed based on palaeobiological indications (i.e., trackmaker identification). High resolution digital photogrammetry method was performed to achieve a more objective representation of footprint three-dimensional morphologies. The footprints under study are compared with Pentasauropus from the Upper Triassic lower Elliot Formation (Stormberg Group) of the Karoo Basin (Lesotho, southern Africa). Some track features suggest a therapsid-grade synapsid as the potential trackmaker, to be sought among anomodont dicynodonts (probably Kannemeyeriiformes). While the interpretation of limb posture in the producer of Pentasauropus tracks from the Los Menucos locality agrees with those described from the dicynodont body fossil record, the autopodial posture does not completely agree. The relative distance between the impression of the digital (ungual) bases and the distal edge of the pad trace characterizing the studied tracks likely indicates a subunguligrade foot posture (i.e., standing on the last and penultimate phalanges) in static stance, but plantiportal (i.e., the whole foot skeleton and related soft tissues are weightbearing) during the dynamics of locomotion. The reconstructed posture might have implied an arched configuration of the articulated metapodials and at least of the proximal phalanges, as well as little movement capabilities of the metapodials. Usually, a subunguligrade-plantiportal autopod has been described for gigantic animals (over six hundreds kilograms of body weight) to obtain an efficient management of body weight. Nevertheless, this kind of autopod is described here for large but not gigantic animals, as the putative trackmakers of Pentasauropus were. This attribution implies that such an autopodial structure was promoted independently from the body size in the putative trackmakers. From an evolutionary point of view, subunguligradeplantiportal autopods not necessarily must be related with an increase in body size, but rather the increase in body size requires a subunguligrade or unguligrade, plantiportal foot. Chronostratigraphically, Pentasauropus was reported from Upper Triassic deposits of South Africa and United States, and from late Middle Triassic and Upper Triassic deposits of Argentina. Based on the stratigraphic distribution of the ichnogenus currently accepted, a Late Triassic age is here proposed for the Pentasauropus-bearing levels of the Los Menucos Group.Fil: Citton, Paolo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigación en Paleobiología y Geología; ArgentinaFil: Díaz Martínez, Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigación en Paleobiología y Geología; ArgentinaFil: de Valais, Silvina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigación en Paleobiología y Geología; ArgentinaFil: Cónsole Gonella, Carlos Alfredo. 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; Argentin

Half a century after the first bootprint on the lunar surface: the ichnological side of the Moon

Humankind began with extra-planetary expeditions in the 1960s. To date, more than fifty manned and unmanned lunar missions have taken place. Maybe, the most iconic image of these campaigns is the bootprint left and photographed by the astronaut Edwin Aldrin. Nevertheless, there is also other evidence of human activities on the Moon, such as rover trails, drill holes, vehicles, and rubbish. For some researchers, ichnology only studies the traces made by one or several individuals with their own bodies, but other authors advocate that artefacts as well as traces made by these artefacts are also traces. In this context, the ichnology of the Moon allows both analysis of the traces left on the lunar surface themselves and discussion of the aim and scopes of ichnology. The Moon ichnology, which arises from the development of hominid ichnology, includes technical artefacts (called technofossils, e.g. Lunar Module, flag, religious text) and traces of technical artefacts (comprised in the new category technotraces, e.g. bootprints, drill holes) but not traces made by individuals with parts of their bodies. Although the lunar environment is very different from that of the Earth due to the absence of atmosphere, magnetic field, water, organic material and life, it is possible to propose three ichnological analogies between the Earth and its satellite. First of all, traces on the Moon surface are subjected to very slow sedimentation rates, similar to what occurs in abyssal bottoms or caves, among other environments. Moreover, physical and mechanical properties allow comparison with processes leading to the formation of traces in volcanic ash deposits with those acting on the soil and regolith of the Moon. Finally, cultural similarities have been identified between the traces left by humans on the Moon and comparable expeditions of humankind, such as Antarctica and the North Pole. The evolution of human technical artefacts has been used to help characterise the onset of the “Anthropocene”. These artefacts can be included within the technosphere and can also be thought to be phenotypic expressions of human genes. Therefore, the traces left on the Moon as well as others which are in other celestial bodies or even in the space, can be considered evidence of extended phenotype of Homo sapiens and the “Anthropocene” beyond the Earth.Fil: Díaz Martínez, Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigación en Paleobiología y Geología; Argentina. Universidad Nacional de Río Negro. Sede Alto Valle. Instituto de Investigaciones en Paleobiología y Geología; ArgentinaFil: Cónsole Gonella, Carlos Alfredo. 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; ArgentinaFil: Citton, Paolo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigación en Paleobiología y Geología; Argentina. Universidad Nacional de Río Negro. Sede Alto Valle. Instituto de Investigaciones en Paleobiología y Geología; ArgentinaFil: de Valais, Silvina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigación en Paleobiología y Geología; Argentina. Universidad Nacional de Río Negro. Sede Alto Valle. Instituto de Investigaciones en Paleobiología y Geología; Argentin

Huellas de vertebrados de la provincia de Río Negro, Patagonia, Argentina: estratigrafía, paleobiología y contextos ambientales

To date, the tetrapod ichnological record in the Río Negro province, Argentina, is known from six areas from the Permo-Triassicto Neogene. Tetrapod tracks have been identified in different palaeoenvironments and geodinamic contexts. The oldest track record is represented by the therapsid tracks from the Los Menucos Group. A prevailing Dicynodontipus and Dicynodontipus-like footprints, Lopingian-Early Triassic in age, comes from the Tscherig and Puesto Vera localities, while Pentasauropus tracks, presumably Late Triassic in age,were recognized in the Yancaqueo locality. A tridactyl track-bearing level, still unpublished (related to El Refugio Formation, Middle-Upper Triassic), has been found in the Puesto Prado farm, in the Arroyo de la Ventana area. Some tracks classified as cf. Anomoepus and undetermined tridactyl tracks have been identified in the Perdomo farm(Marifil Volcanic Complex). The Late Cretaceous (Cenomanian) record is represented by the ornithopod, sauropod and theropod tracks from the Candeleros Formation (Ezequiel Ramos Mexía area). Moreover, cf. Iguanodontipodidae, sauropod and avian tracks from the Anacleto and Allen Formations characterise the latest Cretaceous (Campanian-early Maastrichtian) of the Paso Córdoba area.Avian tracks were also reportedfromthe Ingeniero Jacobacci area, from the Angostura Colorada Formation (upper Campanian-lower Maastrichtian), andfrom the Río Negro Formation (upper Miocene-lower Pliocene) along the shoreline of the province. In this area, tens of tracksites and several ichnotaxa have been studied. In regard of palaeoenvironments, ichnosites are constrained to three main sedimentary settings: fluviovolcaniclastic, fluvial/fluvial-aeolian and shallow marine systems. Finally, a brief discussion about palaeobiology and heritage issues is provided.Hasta la fecha, el registro icnológico de la provincia de Río Negro se conoce en seis áreas que van desde el Pérmico al Neógeno. Las huellas de tetrápodos han sido identificadas en diferentes paleoambientes y contextos geodinámicos. El registro más antiguo son las huellas de terápsidos del Grupo Los Menucos. Las huellas de Dicynodontipus y tipo-Dicynodontipus, dominantes, provienen del Lopingiano-Triásico Inferior, de las localidades de Tscherig y Puesto Vera, mientras que las huellas de Pentasauropus, probablemente del Triásico Superior, provienen de la localidad de Yancaqueo. Un nivel con una huella tridáctila, aún inédito (relacionado con la Formación El Refugio, Triásico Medio- Superior), ha sido hallado en Puesto Prado, área de Arroyo de la Ventana. En Puesto Perdomo (Complejo Volcánico Marifil) se identificaron huellas como cf. Anomoepus y tridáctilas indeterminadas. El registro del área de Ezequiel Ramos Mexía está representado por huellas ornitopodianas, sauropodianas y teropodianas, provenientes de la Formación Candeleros (Cretácico Superior, Cenomaniano). Además, huellas avianas, sauropodianas y cf. Iguanodontipodidae caracterizan el Cretácico final (Campaniano-Maastrichtiano inferior) en el área de Paso Córdoba. En el área de Ingeniero Jacobacci se reportaron huellas avianas de la Formación Angostura Colorada (Campaniano superior-Maastrichtiano inferior), como así también de la Formación Río Negro (Mioceno superior-Plioceno inferior), en la parte costera de la provincia. En esta misma área, se han estudiado decenas de afloramientos y varios icnotaxones. Respecto al paleoambiente, los sitios icnológicos están limitados a tres entornos sedimentarios principales: sistemas fluvio-volcaniclástico, fluvial/fluvio-eólico y marino somero. Finalmente, se provee una breve discusión sobre temas paleobiológicos y patrimoniales.Fil: de Valais, Silvina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Negro. Sede Alto Valle. Instituto de Investigaciones en Paleobiología y Geología; ArgentinaFil: Díaz Martínez, Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Negro. Sede Alto Valle. Instituto de Investigaciones en Paleobiología y Geología; ArgentinaFil: Citton, Paolo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Negro. Sede Alto Valle. Instituto de Investigaciones en Paleobiología y Geología; ArgentinaFil: Cónsole Gonella, Carlos Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. 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; Argentin

Bioerosion and palaeoecological association of osteophagous insects in the Maastrichtian dinosaur Arenysaurus ardevoli

Bioerosions produced by the osteophagous diet of animals that fed on dinosaur bones are very scarce in the European fossil record. Herein we present bioerosion on hadrosaurid remains from the Maastrichtian Tremp Formation of the Pyrenean Basin, which is only the second such case recorded from the Iberian-Occitan Plate besides a sauropod from the Jurassic-Cretaceous of Valencia. The hadrosaurid fossil record is particularly rich in the Blasi sites of the Tremp Formation located in the municipality of Arén (Huesca, Spain). In this article, bones referred to the hadrosaurid Arenysaurus ardevoli from the Blasi-3 site are analysed to shed light on the palaeoenvironment and on the presence of a palaeoecological interaction between the hadrosaurid carcase and osteophagous tracemakers. Bioerosions recorded on the bones comprise tunnels, roundish holes, and straight notches, similar to the traces attributed to necrophagous insects (cf. Cuniculichnus seilacheri). Here, we record the first instance of the activity of these animals on dinosaur bones in the Upper Cretaceous of the Ibero-Occitan Plate. The results presented lead us to infer that the Arenysaurus bones were possibly transported by a storm or similar event to the Blasi-3 site, where they were exposed to post-mortem biotic interactions (eaten and partially decomposed by dermestid beetles) for a prolonged time period before they were completely buried. © 2021 The Authors. Lethaia published by John Wiley & Sons Ltd on behalf of Lethaia Foundatio

Late Permian-Early Jurassic vertebrate tracks from Patagonia : Biochronological inferences and relationships with Southern African realms

In recent years, new studies about vertebrate tracks found in the late Permian-Triassic Los Menucos Complex and Early Jurassic Marifil Volcanic Complex (Río Negro province, Patagonia, Argentina) have been published. In those studies, the chronostratigraphic information of each track-bearing unit has been discussed and the relationships between the record from Patagonia and southern Africa have been highlighted. With the aim of deepening both subjects, the biochronological and palaeobiogeographical information of the main ichnotaxa found in the lower Mesozoic units of Patagonia, Dicynodontipus, Pentasauropus and Anomoepus-like tracks, have been analysed. Moreover, the updated chronological data from the Vera Formation, Los Menucos Complex, in the Tscherig and Yancaqueo farm areas, and from the Marifil Volcanic Complex near Perdomo farm, have been studied. The entire biochronological, chronological and tectonic evidence suggests that within the Los Menucos Complex there are two sequences: a lower one, Wuchiapingian-Olenekian in age, near the Tscherig farm and bearing Dicynodontipus tracks, and an upper sequence of Anisian-Rhaetian (?Norian) age, in the Yancaqueo farm and bearing Pentasauropus tracks. This suggests that the rocks historically defined as Vera Formation have different ages in different areas and span a longer time interval than previously thought. In the case of the Anomoepus-like tracks found in the Marifil Volcanic Complex, the biochronological and geological data are consistent with an Early Jurassic age. According to ichnological information and geological background we propose a correlation between Patagonia and southern Africa constrained in three main phases: 1. Lopingian to Early Triassic, Vera Formation (Tscherig farm) and Balfour Formation, respectively; 2. Middle to Late Triassic, Vera Formation (Yancaqueo farm) and lower Elliot Formation, respectively; and 3. Early Jurassic, Marifil Volcanic Complex and upper Elliot Formation, respectively. In addition, this correlation is supported by a similarity in palaeoclimatic settings that allow inferring a homogeneous distribution of trackmakers in both realms of southern Gondwana. Finally, the palaeobiogeographic information of the studied ichnotaxa and their putative trackmakers is consistent and shows an extensive distribution, during a geotectonic moment with most of the continents assembled forming Pangaea.Fil: Díaz Martínez, Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigación en Paleobiología y Geología; ArgentinaFil: Citton, Paolo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigación en Paleobiología y Geología; ArgentinaFil: de Valais, Silvina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigación en Paleobiología y Geología; ArgentinaFil: Cónsole Gonella, Carlos Alfredo. 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; ArgentinaFil: González, Santiago Nicolás. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigación en Paleobiología y Geología; Argentin

Nuevas evidencias de dinosaurios de la Formación Puerto Yeruá (Cretácico), Provincia de Entre Ríos, Argentina

El territorio argentino ha brindado un amplio y diverso registro de dinosaurios cretácicos, aunque sesgado regionalmente, ya que la mayoría proviene de la Patagonia y unos pocos taxones del noroeste argentino. En el presente trabajo se dan a conocer restos de dinosaurios hallados en la Formación Puerto Yeruá, en dos localidades cercanas a la ciudad de Colón (provincia de Entre Ríos, Argentina), los cuales enriquecen el conocimiento de las faunas de vertebrados extra-patagónicas del Cretácico.Fil: de Valais, Silvina. Museo Paleontológico Egidio Feruglio; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Apesteguía, Sebastián. Gobierno de la Provincia de Rio Negro. Ministerio de Turismo, Cultura y Deporte.; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Udrizar Sauthier, Daniel Edgardo. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleontología Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

La fotogrametría se convierte en una poderosa herramienta para la conservación y difusión del patrimonio paleontológico

La fotogrametría es una disciplina que permite reconstruir un objeto en tres dimensiones mediante fotografías sacadas desde diferentes ángulos. En los últimos años ha habido un apogeo del estudio de fósiles pormedio de visualizaciones digitales tridimensionales. Sus ventajas para la investigación paleontológica sonevidentes: se trata de una técnica no invasiva que permite la exploración in situ, a menor coste que otrosmétodos. Por tanto, la fotogrametría digital está convirtiéndose en una herramienta poderosa y de ampliautilización para la conservación, la divulgación y difusión del patrimonio paleontológico.Fil: Díaz Martínez, Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigación en Paleobiología y Geología; ArgentinaFil: Citton, Paolo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigación en Paleobiología y Geología; ArgentinaFil: de Valais, Silvina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigación en Paleobiología y Geología; ArgentinaFil: García Ortiz de Landaluce, Esperanza. Universidad de la Rioja; Españ

A new pterosaur tracksite from the upper cretaceous Candeleros formation, Neuquén province, Patagonia, Argentina

New pterosaur tracks from the Aguada de Tuco tracksite of the Cenomanian Candeleros Formation (Neuquén Basin, Argentina) are reported here. They are preserved in medium grain-sized sandstones from fluvial deposits and are associated with Arenicolites isp. The pterosaur tracks are preserved as concave and convex epirelief, as true tracks and natural casts, respectively. The manus impressions, which are the most abundant, are usually isolated, although manus-pes sets and sequences of manus-manus imprints, some of them probably representing trackways, have been also documented. The best-preserved manus tracks (average 10.8 cm long, 5.4 cm wide) are tridactyl and strongly asymmetrical. The pes tracks (average 11.5 cm long, 4.8 cm wide) are very elongated, trapezoidal to subtriangular, and generally preserve three-digit impressions. Some morphological track variabilities, such as elongated impressions of manus digit III, has been interpreted as the result of variations in substrate properties, mainly moisture content, and behavior. The main features of the studied tracks, manus and pes track morphologies and length/width ratios, are similar to those of the Pteraichnus ichnogenus. Nevertheless, due to their preservation, not optimal, we classify them as cf. Pteraichnus isp. Only other site with pterosaur tracks has been found in the early Late Cretaceous of South America. These tracks are also in the Candeleros Formation but differ from the Aguada de Tuco ones in having differences in divarication of manus digit impressions, among other features. The present study contributes to the knowledge of the poorly pterosaur track record from Gondwana and its ichnotaxonomic and paleoecological implications.Fil: Heredia, Arturo Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; ArgentinaFil: Díaz Martínez, Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigación en Paleobiología y Geología; ArgentinaFil: Pazos, Pablo Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; ArgentinaFil: de Valais, Silvina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigación en Paleobiología y Geología; ArgentinaXII Congreso de la Asociación Paleontológica ArgentinaTrelewArgentinaAsociación Paleontológica Argentin