Ana María Zavattieri

A new Triassic insect fauna from Cerro Bayo, Potrerillos (Mendoza Province, Argentina) with descriptions of new taxa (Insecta: Blattoptera and Coleoptera)

Martins-Neto, R.G., Gallego, O.F. & Zavattieri, A.M., June, 2007. A new Triassic insect fauna from Cerro Bayo, Potrerillos (Mendoza Province, Argentina) with descriptions of new taxa (Insecta: Blattoptera and Coleoptera). Alcheringa 31, 199‐213. ISSN 0311-5518. This contribution describes new fossil insect taxa from the early Late Triassic Potrerillos Formation (lower section), at quebrada del puente, Cerro Bayo, Mendoza Province, Argentina. A new family, three new genera, and four new species of Blattoptera are described: Anablatta compacta gen. et sp. nov., Potrerilloblatta stipanicici gen. et sp. nov. (Subioblattidae Schneider), Delpuenteblatta dangeloi gen. et sp. nov. and Lariojablatta neiffi sp. nov. (Delpuenteblattidae fam. nov.); and a new coleopteran species, Delpuentesyne menendezi sp. nov. (Permosynidae Tillyard). These findings extend the stratigraphic distribution of the typical Triassic coleopteran taxa. The new assemblage shares the genus Lariojablatta with the Los Rastros fauna. The Blattoptera and Coleoptera genera differ from those typical of the Australian and South African Triassic biota (Ademosyne for Coleoptera and Triassoblatta and Samaroblatta for Blattoptera) and appear to be endemic to Argentina (Delpuentesyne, Potrerilloblatta and Delpuenteblatta).

Estratigrafía, facies y paleoflora de la sucesión triásica de Potrerillos, Mendoza, República Argentina

Nuevas exposiciones en localidades triasicas clasicas como las de los cerros Bayo y Cocodrilo (Potrerillos, noroeste de la Provincia de Mendoza, Argentina) permitieron (1) describir y caracterizar las formaciones Rio Mendoza, Cerro de Las Cabras, Potrerillos y Cacheuta; y (2) mejorar el conocimiento bioestratigrafico de las sucesiones triasicas basandose en el hallazgo de nuevos registros de plantas fosiles. Dos secciones verticales fueron estudiadas en detalle, y el analisis de las litofacies ha sido usado para interpretar los sistemas de deposicion. Facies gruesas de abanico aluvial caracterizan a la Formacion Rio Mendoza y a la seccion inferior de la Formacion Potrerillos. Sistemas fluviales traccionales gravosos y arenosos aparecen hacia el techo de la Formacion Rio Mendoza y en distintos intervalos de la Formacion Potrerillos. En el tramo basal de la Formacion Cerro de Las Cabras y en la mayor parte de la Formacion Potrerillos se identificaron depositos de sistemas fluviales de alta sinuosidad y de planicies de inundacion. Finalmente, algunos intervalos de la Formacion Potrerillos y mas especificamente la Formacion Cacheuta estan dominados por sucesiones de lutitas negras generadas por procesos suspensivos en lagos meromicticos. En asociacion con los depositos mencionados, secuencias progradacionales discretas de areniscas y conglomerados sugieren el desarrollo de barras de desembocadura hipopicnales y de canales distributarios. Se individualizaron 16 niveles fosiliferos con 23 taxones: Equisetites fertilis, Neocalamites carrerei, Cladophlebis mesozoica, C. mendozaensis, Dicroidium argenteum, D. dubium, D. odontopteroides, Johnstonia coriacea, J. stelzneriana, Xylopteris elongata, Zuberia feistmanteli, Feruglioa samaroides, Pachydermophyllum praecordillerae, Kurtziana cacheutensis, Sphenobaiera argentinae, Baiera africana, B. cuyana, Yabeiella mareyesiaca, Y. spathulata, Y. brackebuschiana, Fraxinopsis andium y Gontriglossa sp. y Rochipteris sp. Se describieron 16 tafocenosis que se relacionaron con los respectivos ambientes de sedimentacion. El analisis de las tafocenosis y su vinculacion con las facies y paleoambientes de acumulacion permitio reconocer en la localidad tipo de la Formacion Potrerillos a dos biozonas de asociacion en continuidad estratigrafica (Yabeiella mereyesiaca-Scytophyllum bonettiae-Protophyllocladoxylon cortaderitaensis -MBC- y Yabeiella brackebuschiana-Scytophyllum neuburgianum-Rhexoxylon piatnitzkyi -BNP-). La Formacion Potrerillos en este sector de la cuenca se desarrollo durante el Triasico Medio tardio-Triasico Tardio temprano

Estudio palinológico de la formación la veteada en su localidad tipo (Pérmico superior), Sierra de Famatina, La Rioja, Argentina. Granos de polen estriados, plicados y colpados

Abstract. PALYNOLOGICAL STUDY OF LA VETEADA FORMATION AT ITS TYPE LOCALITY (UPPER PERMIAN), FAMATINA RANGE, LA RIOJA PROVINCE, ARGENTINA. STRIATE, PLICATE AND COLPATE POLLEN GRAINS. This is a systematic study of the palynological assemblages recorded in the upper part of the La Veteada Formation (upper La Veteada Association), which constitutes the section of the type locality, La Rioja Province, Argentina. In this contribution, 72 species of striate (monosaccate and bisaccate), plicates and colpate pollen grains are presented. Four new species are described: Meristocorpus veteadensis sp. nov., Lueckisporites biformis sp. nov., Lunatisporites lenticularis sp. nov., and Marsupipollenites costatus sp. nov. and, a new combination, i.e., Striatopodocarpites gopadensis (Bharadwaj and Srivastava) comb. nov is proposed. This palynoflora has a marked dominance of striate pollen grains which have great species diversity of Striatopodocarpites (with 11 species)-Protohaploxypinus (9 species)-Lueckisporites (9 specics)-Lunatisporites (8 species) complex, showing scarse participation of the genera Vittatina, Weylandites, Marsupipollenites, Corisaccites, Staurosaccites and Pakhapites, as well as pollen grains referred to Cordaitales (Potonieisporites, Cannanorop ollis, Caheniasaccites, Plicatipollenites, Barakarites). It shares taxa recorded in the LW (Argentina), Vc-Lv (Brazil) and IS-AC (Uruguay) biozones. Tables include full taxonomic composition of the microflora of the La Veteada Formation at its type locality, the palynostratigraphic correlation of the Neopaleozoic strata of central Argentina, southern Brazil and Uruguay, and the global previous stratigraphic records of the species recorded and discussed herein. The palynoflora of the upper La Veteada Formation is referred to the Late Permian (Lopingian) based on the stratigraphic range of all the recognized species. Consequently, it is considered the youngest Permian palynoflora recorded hitherto in Argentina and South America.

The first spinicaudatan (Crustacea: Diplostraca) from Permo-Triassic continental sequences of South America and its palaeoecological context

Tassi, L.V., Monti, M., Gallego, O.F., Zavattieri, A.M. & Lara, M.B., 2013. The first spinicaudatan (Crustacea:Diplostraca) from Permo-Triassic continental sequences in South America and its palaeoecological context. Alcheringa 37, 187–199. ISSN 0311-5518. Cornia martinsnetoi sp. nov., the first spinicaudatan from Permian–Triassic continental sequences of southern South America, is described. The new species has characters diagnostic of the typical late Palaeozoic–Early Triassic subfamily Vertexiinae from Gondwana. This new taxon was found in tuffaceous siltstones in the upper part of the Quebrada de los Fósiles Formation (Puesto Viejo Group), which may span the Permo-Triassic boundary in Argentina. The lower and coarser-grained interval of the Quebrada de los Fósiles Formation was deposited in distal alluvial fans and low- to high-sinuosity rivers. The upper fine-grained interval of this formation, which hosts the spinicaudatans and associated fossils (ostracods, megaspores, fish scales), was deposited in shallow floodplain lakes. Intense volcanic activity influenced the sedimentary evolution of this succession and was accompanied by aridification and some climatic seasonality that likely generated stressful conditions for the biota. Previous biostratigraphic studies support an Early Triassic age for the beds containing Cornia martinsnetoi sp. nov. [Lara Vaz Tassi [larinhatassi@hotmail]com], Área Paleontología (Centro de Ecología Aplicada del Litoral—Centro Científico Tecnológico Nordeste—Consejo Nacional de Investigaciones Científicas y Técnicas), Casilla de Correo 128, 3400 Corrientes, Argentina; Mariana Monti [marimontivaldes@yahoo.com.ar], Departamento de Geología, Museo de Historia Natural de San Rafael—Parque Mariano Moreno s/n°, 5600 San Rafael, Mendoza, Argentina; Oscar Florencio Gallego [ofgallego@live.com.ar], Micropaleontología (Facultad de Ciencias Exactas y Naturales y Agrimensura—Universidad Nacional del Nordeste), Corrientes, Argentina and Área Paleontología (Centro de Ecología Aplicada del Litoral—Centro Científico Tecnológico Nordeste—Consejo Nacional de Investigaciones Científicas y Técnicas), Casilla de Correo 128, 3400 Corrientes, Argentina; Ana María Zavattieri [amz@mendoza-conicet.gov.ar], Laboratorio de Paleopalinología (Instituto Argentino de Nivología y Glaciología y Ciencias Ambientales—Centro Científico Tecnológico—Consejo Nacional de Investigaciones Científicas y Técnicas), Casilla de Correo 131, 5500 Mendoza, Argentina; Maria Belén Lara [lara.maria.belen@live.com.ar], Área Paleontología (Centro de Ecología Aplicada del Litoral—Centro Científico Tecnológico Nordeste—Consejo Nacional de Investigaciones Científicas y Técnicas), Casilla de Correo 128, 3400 Corrientes, Argentina. Received 3.5.2012; revised 22.8.2012; accepted 11.9.2012.

CONIFEROUS WOODS AND WOOD-DECAYING FUNGI FROM THE EL FRENO FORMATION (LOWER JURASSIC), NEUQUEN BASIN, MENDOZA PROVINCE, ARGENTINA

Abstract. Two species of coniferous silicified wood are described from the El Freno Formation (Lower Jurassic) at Cerro La Brea, on the southern margin of the Atuel River, southern Mendoza Province, Argentina. Agathoxylon liguaensis Torres and Philippe (Araucariaceae) and the new species Podocarpoxylon atuelensis sp. nov. (Podocarpaceae) were described based on a detailed description of the secondary xylem. Wood specimens are well preserved, although some sections display variably decaying cell-walls typical of white-rotting by extant fungi. Vegetative and sexual structures in the degraded areas are identifiable as basidiomycetes. This is consistent with fungal saprotrophism and supports the role of fungi in the recycling of the organic matter in Mesozoic terrestrial ecosystems. Considering the available geochronologic and biostratigraphic data and the current lithostratigraphic settings proposed for the unit, the age of the El Freno Formation at the studied locality can be constrained to the Hettangian-Sinemurian.

The Palynology of the Cañadón Asfalto Formation (Jurassic), Cerro Cóndor Depocentre, Cañadón Asfalto Basin, Patagonia, Argentina: Palaeoecology and Palaeoclimate Based on Ecogroup Analysis

The Cañadón Asfalto Formation, Cañadón Asfalto Basin, Patagonia, Argentina, is interpreted as fluvial-lacustrine deposits. A palynological study of the lower and middle parts of the unit, at the Cañadón Lahuincó and Cañadón Caracoles sections, Cerro Cóndor Depocentre Chubut province, northwestern Patagonia, Argentina is presented. The quantitative composition of the palynofloras is characterised by the dominance of pollen produced by the conifer families Cheirolepidiaceae (Classopollis) and Araucariaceae (mainly Araucariacites and Callialasporites), suggesting that warm-temperate and relatively humid conditions under highly seasonal climate prevailed during the depositional times of the unit. The abundance of Botryococcus supports the presence of a shallow lake with probably saline conditions. Five palynomorph ecogroups (PEGs) were recognised: upland, lowland, riverside, coastal lake and aquatic. The ecological requirements of the different plant families forming the PEGs enable the inference of a sub-tropical palaeoclimate for the Cañadón Asfalto region during late Early Jurassic to mid Middle Jurassic, which is consistent with the ‘seasonally dry (winterwet)‘ biome.

The Paleobotanical Record of the Triassic Cerro de las Cabras Formation at Its Type Locality, Potrerillos, Mendoza (Uspallata Group): An Historical Account and First Record of Fossil Flora

Abstract. The first fossil macroflora assemblage from the Cerro de Las Cabras Formation at its type locality, in the Potrerillos area, is presented. The area is tectonically altered, which is why there have been several different interpretations about the real thickness and boundaries of the formation. A detailed analysis of the bibliography showed that previous fossil plant taxa referred to the Cerro de Las Cabras Formation belonged to the overlying Potrerillos Formation. However, the recent discovery of a plant-bearing level in stratigraphically constrained sediments of the Cerro de Las Cabras Formation allows the identification of a flora composed of Corystospermales —Dicroidium odontopteroides (Morris) Gothan; D. lancifolium (Morris) Gothan; D. crassum (Menéndez) Petriella; Zuberia zuberi (Szajnocha) Frengüelli; Z. sp. cf. Z. barrealensis Frengüelli—, Peltaspermales —Scytophyllum sp. cf. S. neuburgianum Dobruskina; Pachydermophyllum sp.; Peltaspermum sp.—, putative Gnetales — Gontriglossa sp.—, Osmundales —Cladophlebis mendozaensis (Geinitz) Frengüelli—, Equisetales, and two taxa of uncertain affinities. Although low in diversity, this assemblage is comparable to coeval assemblages in other basins, particularly the floras from the Agua de los Pajaritos, Barreal and Ischichuca formations, reinforcing the Middle Triassic age assigned by the vertebrate, microfloristic and radiometric dating.

The Fungal Spore Annella capitata Srivastava from the Jurassic (Late Toarcian—Late Bajocian) Cañadón Asfalto Formation of Patagonia, Argentina

The fungal spore Annella capitata Srivastava is recorded for the first time in Argentina, within the continental Jurassic strata of the Cañadón Asfalto Formation, Cañadón Asfalto Basin, Patagonia. It is identified on pollen grains belonging to the Cheirolepideaceae, Araucariaceae and Podocarpaceae. This paper contrasts A. capitata with ubisch bodies (small sporopollenin spherules attached to the exine). A. capitata has the same characteristics in the different pollen taxa, while the ubish bodies exhibit taxon-dependent differences in ultrastructure, size and morphology. The presence of hyphae and spore germlings reinforces a fungal origin of A. capitata. The degree and type of deterioration associated with these fungal microfossils are presented. Based upon the ecological requirements of the plant families recognized in the Cañadón Asfalto palynoflora, it is inferred that A. capitata Srivastava thrived in low-energy environments under warm-temperate and humid conditions.

TRIASSIC SPINICAUDATAN FAUNA FROM THE CERRO DE LAS CABRAS FORMATION (CUYO BASIN), MENDOZA PROVINCE (ARGENTINA): DESCRIPTION OF NEW SPECIES AND REVISION OF PREVIOUS RECORDS

Abstract. This is a systematic study of the Spinicaudata fauna of the Cerro de Las Cabras Formation (Middle Triassic), north of Cerro Bayo, in the classical Potrerillos area, Precordillera of Mendoza, Cuyo Basin, Argentina. Two new species are described: Estheriellites zavattieriae sp. nov. and Euestheria menendezi sp. nov.. The diagnosis of the genus and species of Challaolimnadiopsis mendozaensis Shen and Gallego, is emended; and Euestheria martinsnetoi Gallego et al., previously described for the Río Mendoza Formation is now considered as coming from the Cerro de Las Cabras strata. The studied section consists mainly of fine-grained tuffaceous sandstones and interbedded mudstones interpreted as playa lake, ephemeral rivers and/or streams developed in the floodplain. Ephemeral to shallow lacustrine environments are characterized by interbedded siltstones, nodular-mottle and stromatolitic limestones with sub-aerial exposures and incipient soil development in depressed and flood-prone areas under seasonal semi-arid conditions. Spinicaudatans probably inhabited lacustrine shorelines and small ponds in the floodplain where plant remains (arthrophyte) and rare fish scales were also recorded. The profuse presence of pyroclastic deposits along the sequence indicates considerable explosive volcanic activity coeval with sedimentation. Based on previous lithostratigraphical, paleontological and chronological data, the age of the studied deposits was constrained to Middle Triassic (equivalent to Late Anisian—Late Ladinian of marine sequences) and therefore the E. zavattieriae-E. martinsnetoi Faunal Association is considered as a marker for such age range.

PALYNOLOGY OF THE LA VETEADA FORMATION (LOPINGIAN) AT ITS TYPE LOCALITY, FAMATINA RANGE, LA RIOJA PROVINCE, ARGENTINA. SPORES

Abstract. In this systematic study of palynological assemblages from the upper part of the type section of the La Veteada Formation, 38 species of trilete and monolete spores are described and/or illustrated. Two new species are instituted: Lundbladispora verrucosa and Secarisporites triangularis, and a new combination Secarisporites imperialis (Jansonius) is proposed. Trilete spores comprise a dominant group in the analyzed palynoflora and show a reduced frequency from the base to the top of the section (from 32.2 to 14.5%). Cinguli-cavate spores (derived from herbaceous lycophytes) are dominant and represented by the genera Densoisporites, Lundbladispora and Secarisporites. Smooth and apiculate trilete spores (derived from ferns and sphenopsids) are represented by genera such as Calamospora, Punctatisporites, Granulatisporites, Brevitriletes, Cyclogranisporites and Osmundacidites. This upper section of the La Veteada Formation was deposited in fluvialhypersaline/ brackish lacustrine environments under arid to semiarid climatic conditions. The areas surrounding these water-bodies dominated by evaporites were vegetated mainly by herbaceous lycopsids (Isoetales, Selaginellales, Lycopodiales) and ferns. Pteridophytes (Filicales, Zygopteridales), bryophytes and herbaceous sphenophytes were developed along the river courses and in the surrounding areas of freshwater bodies (ponds and small lakes) on the flood plain. The presence of Densoisporites complicatus, D. nejburgii, D. playfordii, D. solidus, Leptolepidites jonkeri, Lundbladispora brevicula, L. obsoleta, L. springsurensis, L. wilmotti, Ringosporites fossulatus, Secarisporites bullatus, S. imperialis and S. lacunatus confirm a late Permian (Lopingian) age for the upper La Veteada Formation. The palynofloras contain significant proportions of lycopsid tetrads; as is the case with many extra-Gondwanic strata of Lopingian/Early Triassic age.