Improving the facies models for syn-eruptive fluvial successions: lessons from the Chaitén Volcano and Blanco River, Chile

Typically, the stratigraphic record of syn-eruptive fluvial successions is a pyroclastic-rich one. It includes an alternation of braided channel deposits and sheet-like floodplain strata, in which the occurrence of paleosols with in situ trees and primary pyroclastic deposits is common. The participation of facies formed from sediment-laden flows is also a conspicuous feature in these successions. Nevertheless, the disturbances occurred in the chilean Blanco River in 2008, as a consequence of the large tephra influx from the Chaitén Volcano eruption, result in discrepancies with the mentioned conceptual background including the plan-view form and filling of channels, and lateral compositional changes along the river. These discrepancies would response to local conditions such as precipitation, vegetation, topography, and type and amount of available sediment. Furthermore, the connection between the Blanco River and the Pacific Ocean, adds an additional feature to syn-eruptive fluvial successions, represented by associated delta plain deposits composed of volcaniclastic sands.Fil: Umazano, Aldo Martin. 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; ArgentinaFil: Bedatou, Emilio. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales; Argentina. 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; ArgentinaFil: Krause, Javier Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Museo Paleontológico Egidio Feruglio; ArgentinaFil: Bellosi, Eduardo Sergio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Villegas, Pablo Martin. 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; Argentin

Improving the facies models for syn-eruptive fluvial successions: lessons from the Chaitén Volcano and Blanco River, Chile

Typically, the stratigraphic record of syn-eruptive fluvial successions is a pyroclastic-rich one. It includes an alternation of braided channel deposits and sheet-like floodplain strata, in which the occurrence of paleosols with in situ trees and primary pyroclastic deposits is common. The participation of facies formed from sediment-laden flows is also a conspicuous feature in these successions. Nevertheless, the disturbances occurred in the chilean Blanco River in 2008, as a consequence of the large tephra influx from the Chaitén Volcano eruption, result in discrepancies with the mentioned conceptual background including the plan-view form and filling of channels, and lateral compositional changes along the river. These discrepancies would response to local conditions such as precipitation, vegetation, topography, and type and amount of available sediment. Furthermore, the connection between the Blanco River and the Pacific Ocean, adds an additional feature to syn-eruptive fluvial successions, represented by associated delta plain deposits composed of volcaniclastic sands.Fil: Umazano, Aldo Martin. 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; ArgentinaFil: Bedatou, Emilio. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales; Argentina. 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; ArgentinaFil: Krause, Javier Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Museo Paleontológico Egidio Feruglio; ArgentinaFil: Bellosi, Eduardo Sergio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Villegas, Pablo Martin. 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; Argentin

Improving the facies model for syn-eruptive fluvial successions: lessons from the Chaitén volcano and Blanco river, Chile.

Typically, the stratigraphic record of syn-eruptive fluvial successions is a pyroclastic-rich one. It includes an alternation of braided channel deposits and sheet-like floodplain strata, in which the occurrence of paleosols with in situ trees and primary pyroclastic deposits is common. The participation of facies formed from sediment-laden flows is also a conspicuous feature in these successions. Nevertheless, the disturbances occurred in the chilean Blanco River in 2008, as a consequence of the large tephra influx from the Chaitén Volcano eruption, result in discrepancies with the mentioned conceptual background including the plan-view form and filling of channels, and lateral compositional changes along the river. These discrepancies would response to local conditions such as precipitation, vegetation, topography, and type and amount of available sediment. Furthermore, the connection between the Blanco River and the Pacific Ocean, adds an additional feature to syn-eruptive fluvial successions, represented by associated delta plain deposits composed of volcaniclastic sands

Terrestrial crustacean breeding trace fossils from the Cretaceous of Patagonia (Argentina): Palaeobiological and evolutionary significance

The breeding trace fossils described herein along with the high density of Loloichnus baqueroensis in the Cretaceous formations of Patagonia suggest that crayfishes were soil engineers along the Cretaceous in southern South America, and that they had acquired many of the K-breeding behaviours recorded by insects in latest and post-Cretaceous soils, such as pelletal constructions and excavation of breeding cells. The K-T event was probably responsible for changes in environmental conditions in such a way that crayfishes finally became restricted to two small distributional areas in southern South America, and K-breeding insects replaced them as keystone organisms in Cainozoic and modern soils. Dagnichnus titoi igen. and isp. nov. and Cellicalichnus meniscatus isp. nov., are created to include the new trace fossils attributable to crayfishes from the Cretaceous of Patagonia, Argentina. The attribution to crayfishes is based on their association and morphological affinities with the crayfish fossil burrows L. baqueroensis from the same geologic units. D. titoi is represented by hemispherical chambers surrounded by thick and short, meniscate burrows, which can be arranged in two or three tight whorls in the more regular specimens. Meniscate burrows are curved downwards and have no neck. Walls are unlined. C. meniscatus are necked, horizontal, and straight cells, showing meniscate fillings, attached to sub-vertical shafts, which are relatively much wider than the neck of cells. Both, shafts and cells show a thin and smooth lining. The presence of cells or burrows smaller than the putative parental burrows and comparisons with breeding traces of marine Decapoda support the interpretation of breeding traces, Calichnia, of terrestrial crustaceans. C. meniscatus is interpreted as cells excavated from parental burrows, whereas D. titoi are probably breeding structures completely produced in a different palaeoenvironment where the female release juveniles.Fil: Genise, Jorge Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Museo Paleontológico Egidio Feruglio; ArgentinaFil: Bedatou, Emilio. 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; ArgentinaFil: Melchor, Ricardo Nestor. 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; Argentin

<i>Spongeliomorpha </i>in nonmarine settings:an ichnotaxonomic approach

The authors revise the occurrences of burrow networks with striated walls having dominantly transverse to oblique striae, which have been assigned to the ichnogenera Spongeliomorpha Saporta, 1887, and Steinichnus Bromley & Asgaard, 1979. The taxonomic status of the ichnogenus Steinichnus Bromley & Asgaard, 1979 is examined and it is suggested that this ichnogenus is a subjective junior synonym of Spongeliomorpha Saporta, 1887. Spongeliomorpha is best reserved for an unlined network of burrows having distinct surface ridges or grooves of different orientation and massive filling. The diagnosis of Spongeliomorpha is emended accordingly and the proposed ichnospecies revised for consistency with the diagnostic features of the ichnogenus. Spongeliomorpha milfordensis Metz, 1993a is considered a subjective junior synonym of Spongeliomorpha carlsbergi (Bromley & Asgaard, 1979) after a visual comparison and statistical analysis of the angle of striation with respect to the burrow midline in the type material. Nevertheless, the use of statistical techniques is not advocated for distinction of ichnotaxa, but may support observations. Spongeliomorpha carlsbergi is considered as an indicator of nonmarine settings and was probably produced by burrowing insects. Proposed ichnospecies of Spongeliomorpha that fit the emended diagnosis include S. sudolica (Zarczny, 1878); S. iberica Saporta, 1887; S. sicula DAlessandro & Bromley, 1995; S. chevronensis Muiz & Mayoral, 2001; and Spongeliomorpha isp. nov. aff. sicula Lewy & Goldring, 2006.Fil: Melchor, Ricardo Nestor. 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; ArgentinaFil: Bromley, Richard G.. Copenhagen University; DinamarcaFil: Bedatou, Emilio. 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; Argentin

Contributions of ichnology to palaeoecology, palaeogeography, and sedimentology. A special issue related to the Second Latin-American Symposium on Ichnology (SLIC 2013)

Fil: Melchor, Ricardo Nestor. 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; ArgentinaFil: Bedatou, Emilio. 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; ArgentinaFil: Verde, Mariano. Universidad de la República; UruguayFil: Loope, David. University of Nebraska; Estados Unido

Crayfish burrows from Late Jurassic-Late Cretaceous continental deposits of Patagonia: Argentina. Their palaeoecological, palaeoclimatic and palaeobiogeographical significance

The trace fossil, Loloichnus baqueroensis igen. and isp. nov., from Late Jurassic-Late Cretaceous continental deposits of Patagonia, Argentina, includes thickly lined, mostly passively-filled, and Y-branched burrows. Other important features of this ichnofossil are the inner surface texture of lining showing transversal, elongated, and adjacent grooves, and less commonly, the pelletal filling of burrows. L. baqueroensis is recorded from the Bajo Grande, Bajo Tigre, Punta del Barco, and Laguna Palacios Formations, which were deposited in different volcaniclastic environments of the Deseado Massif and San Jorge Basin geological provinces, respectively. The described burrows are found in many levels of palaeosols developed in reworked piroclastic deposits, where they are the main component of the ichnofabrics, in association with meniscate and thinly lined burrows and a diffuse and complex boxwork of small diameter burrows. Root traces are also present, and in many cases, occur inside L. baqueroensis. Considering general morphology, surface texture, filling types, palaeoenvironments in which they occur, and comparisons with extant and fossil decapod burrows, the likely trace makers of L. baqueroensis were crayfishes (Decapoda: Astacidea), probably Parastacidae. The producers of L. baqueroensis inhabited soils, where their burrows probably reached the water table, and contained roots that were used for feeding. Considering climatic preferences of extant parastacids, it is proposed a temperate climate for central Patagonia during the deposition of the studied units. The widespread presence of crayfishes during Late Jurassic-Late Cretaceous times in central Patagonia, supports the monophyletic origin of this group during the Triassic, and suggests that the present restricted geographic distribution in southern South America is a relict of a broader one.Fil: Bedatou, Emilio. 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; ArgentinaFil: Melchor, Ricardo Nestor. 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; ArgentinaFil: Bellosi, Eduardo Sergio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; ArgentinaFil: Genise, Jorge Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Museo Paleontológico Egidio Feruglio; Argentin

Lithofacies distribution of invertebrate and vertebrate trace-fossil assemblages in an Early Mesozoic ephemeral fluvio-lacustrine system from Argentina: Implications for the Scoyenia ichnofacies

This paper discusses the lithofacies distribution and ichnotaxonomic assignment of invertebrate, vertebrate and plant trace fossils in an Early Mesozoic ephemeral fluvio-lacustrine system from northwest Argentina. The overall palaeoenvironment is envisaged as a distal, low-gradient fluvio-lacustrine setting under semi-arid climate, similar to a terminal fan. Depositional lobes (facies association A) are composed of distributary ribbon channels (facies A1), and associated pond and sheetflood deposits (facies A2). Lowlands between depositional lobes (facies association B) contained poorly drained floodplain zones similar to wetlands (facies B1) and shallow closed lakes (facies B2). Depositional lobes were fringed by playa-lake settings (facies association C), including mudflats (facies C1) that are partially eroded by ephemeral fluvial channels (facies C2). The ichnofauna of the Santo Domingo Formation displays high ichnodiversity (30 trace fossil types) and includes 5 trace fossil assemblages that are linked to sedimentary facies. These trace fossil assemblages are highly distinctive as half of the recognised trace fossil types are assigned to different assemblages. The ephemeral fluvial channel assemblage (facies A1 and C2) displays the lower ichnodiversity (n = 6) and includes Skolithos linearis, Diplichnites sp., Palaeophycus tubularis, Taenidium barretti, Dicynodontipus sp. and footprints in cross-section. The floodplain pond assemblage (facies A2) shows the higher ichnodiversity (n = 15) and is composed of Diplichnites sp., Helminthoidichnites tenuis, P. tubularis, Rusophycus carbonarius, S. linearis, Spongeliomorpha carlsbergi, T. barretti, appendage marks, burrows with brush-like features, epichnial bilobed traces, hypichnial bilobed ridges, bird-like footprint type A, tridactyl footprints, footprints preserved in cross-section, and small epichnial rounded pits. The poorly drained floodplain assemblage (facies B1) is of moderate ichnodiversity (n = 10) and consists of H. tenuis, S. carlsbergi, ?Spongeliomorpha sp., imbricated backfilled burrow fillings, root trace type A, Tetrasauropus sp., bird-like footprint type A, large pentadactyl footprints, tridactyl footprints, and footprints preserved in cross-section. The high ichnodiversity (n = 13) nearshore lacustrine assemblage (facies B2) is the only assemblage that lacks vertebrate traces, and is composed of Cochlichnus anguineus, Cruziana problematica, H. tenuis, Palaeophycus heberti, P. striatus, P. tubularis, Scoyenia gracilis, S. carlsbergi, T. barretti, epichnial bilobed traces, hypichnial bilobed ridges, root trace type B, and scratch marks. The intermediate ichnodiversity (n = 9) mudflat assemblage (facies C1) is typified by the largest ichnodiversity of vertebrate tracks and includes H. tenuis, P. tubularis, S. carlsbergi, Dicynodontipus sp., Tetrasauropus sp., bird-like footprints of types B and C, large pentadactyl footprints, and tridactyl footprints. The trace fossil assemblages from Santo Domingo Formation are typical representatives of the Scoyenia ichnofacies. The distinctiveness of the studied trace fossil assemblages suggests that a future division of the Scoyenia ichnofacies would be possible, provided that occurrences of invertebrate, vertebrate and plant trace fossils in definite sedimentary facies are considered. The subdivision of the Scoyenia ichnofacies into recurrent groups of trace fossils (ichnosubfacies) with a palaeoecological and palaeoenvironmental meaning can be based on two approaches: distinction of associations of vertebrate tracks and recognition of ichnocoenoses related to substrates with different degrees of water saturation and firmness. The first approach can be based on an evaluation of the recurrent vertebrate ichnoceonoses used to recognise vertebrate ichnofacies. In this way, some of the candidate vertebrate ichnofacies are proposed as subdivisions of the Scoyenia ichnofacies. The second approach is based on the identification of crosscutting relationships between trace fossils and between trace fossils and sedimentary structures within some trace fossil assemblages. Using this methodology, it is possible to define distinct assemblages of trace fossils: a "pre-desiccation suite" with structures lacking ornamentation and developed in a soft substrate and a "desiccation suite" typified by striated traces that crosscut the former. These trace-fossil assemblages help to characterise the changes in organism-sediment interaction during progressive desiccation of a water-lain substrate. Additional neoichnological studies are necessary to assess the exact meaning of different trace fossil features in terms of substrate consistency.Fil: Melchor, Ricardo Nestor. 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; ArgentinaFil: Bedatou, Emilio. 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; ArgentinaFil: de Valais, Silvina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Museo Paleontológico Egidio Feruglio; ArgentinaFil: Genise, Jorge Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Museo Paleontológico Egidio Feruglio; Argentin

Curved fossil bee cells as tools for reconstructing the evolutionary history and geographic palaeodistribution of Diphaglossinae (Apoidea, Colletidae)

The new ichnospecies Celliforma curvata is described to include curved fossil bee cells from Argentina, Uruguay and the USA. The upper part of the cell (neck) of the new ichnospecies is curved, and accordingly, it can be attributed to bees of the subfamily Diphaglossinae (Colletidae). The oldest record of C. curvata, from the early Eocene of North America (52-49 Ma), provides a minimum age for the appearance of this subfamily, in accordance with an already proposed calibrated phylogeny. It is also proposed that these fossil cells could be used for future calibrations of molecular clocks. C. curvata indicates that Diphaglossinae had a widespread distribution, from southern Utah to extra-Andean Patagonia at 42°S. In contrast, extant representatives reach only 38°S in this region. Diphaglossinae were more extended southwards in the past thanks to better environmental conditions in extra-Andean Patagonia.Fil: Sarzetti, Laura Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "bernardino Rivadavia"; ArgentinaFil: Dinghi, Pablo Adrián. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Genise, Jorge Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "bernardino Rivadavia"; ArgentinaFil: Bedatou, Emilio. Universidad Nacional de la Pampa. Facultad de Cs.exactas y Naturales. Departamento de Cs.naturales. Pabellon de Geología; Argentina. 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 Cs.exactas y Naturales. Instituto de Ciencias de la Tierra y Ambientales de la Pampa; ArgentinaFil: Verde, Mariano. Universidad de la Republica. Instituto de Ciencias Geológicas; Urugua

Fluvial response to sudden input of pyroclastic sediments during the 2008–2009 eruption of the Chaitén Volcano (Chile): The role of logjams

The rhyolitic Plinian eruption of the Chilean Chaitén Volcano, initiated on May 2, 2008, suddenly introduced abundant pyroclastic sediments in the Blanco River catchment area, which experienced important modifications. Before May 2, the river was characterised by gravelly and moderate to low-sinuosity channels crossing a vegetated and locally urbanised (Chaitén City) floodplain. This river, limited by steep and densely forested highlands, was connected with the Pacific Ocean via a tidally-influenced delta plain. After heavy rains in May 11–20, the river discharge increased and triggered several responses including logjam formation and breakage, crevassing, avulsion (and channel abandonment), changes in the pattern and dimensions of channels, and construction of a new delta plain area. In this context, the goals of this contribution were: i) to document the sedimentological processes within a detailed geomorphic framework and ii) to understand the influence of logjams on fluvial dynamics. Upstream of the logjam zone, the deposits are mostly composed of ash and lapilli with abundant palaeovolcanic (epiclastic) sediments, which were produced by dilute currents and debris flows. Downstream of the logjam zone, deposits are composed by ash and lapilli, both pumice-rich and lacking important participation of older (epiclastic) sediments. The abandoned and filled palaeochannel, and the proximal part of crevasse splays experienced transient dilute flows with variable sediment concentration and, subordinately, hyperconcentrated flows. The distal sectors of crevasse splays mostly record settling from suspension. At the delta plain, tephra transported by the Blanco River was mixed with older sediments by tide and wave action (dilute flows). We conclude that immediately after eruption, both geomorphic and sedimentary processes of the river were mainly controlled by a combination of high availability of incoherent pyroclastic sediments on steep slopes, abundant rains, large logs that jammed the river and huge areas of devastated forest. Logjams played an important role in the river response to the volcanic eruption; they were responsible of the marked compositional change recorded upstream and downstream of the logjam zone and its breakage resulted in downstream flooding and avulsion. The likelihood of formation of logjams in rivers draining forested volcanic areas should be considered in the evaluation of volcanic hazards related to Plinian eruptions.Fil: Umazano, Aldo Martin. 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; ArgentinaFil: Melchor, Ricardo Nestor. 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; ArgentinaFil: Bedatou, Emilio. 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; ArgentinaFil: Bellosi, Eduardo Sergio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Krause, Javier Marcelo. Museo Paleontológico Egidio Feruglio; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin