Pedro R. Gutiérrez

Palynostratigraphy of upper Paleozoic sequences in central‐western Argentina

Lower Carboniferous to Permian palynological zones are described from sections in central–western Argentina. In ascending stratigraphic order these zones are: (1) the Cordylosporites– Verrucosisporites (CV) Assemblage Biozone (spanning the Maliman and Cortaderas formations); (2) the Raistrickia densa– Convolutispora muriornata (DM) Assemblage Biozone (which is subdivided into: Sub-biozone A in the Guandacol and equivalent formations, Sub-biozone B in the Tupe Formation and equivalents, and Sub-biozone C in the upper part of the Santa Maxima and El Imperial formations); (3) the Fusacolpites fusus–Vittatina subsaccata (FS) Interval Biozone in the Bajo de Veliz and Tasa Cuna formations and equivalents, and (4) the Lueckisporites– Weylandites (LW) Assemblage Biozone in the De La Cuesta and Yacimiento Los Reyunos formations. The oldest biozone (CV) is assigned to the Early Carboniferous and the overlying DM Biozone to the Late Carboniferous. The uppermost FS and LW biozones are Permian in age. Palynological records show the impact of the Early-to-Late Carboniferous glacial event, which caused significant changes in the composition of the assemblages from this interval. Further studies are necessary to calibrate a regional geological time scale in Gondwana, which is essential for precise correlation.

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 lycophytes of the La Golondrina Formation (Permian), Santa Cruz Province, Argentina: systematic revision, biostratigraphy and palaeoecology

Cariglino, B., Coturel, E.P. & Gutiérrez, P.R., iFirst article, 2012. The lycophytes of the La Golondrina Formation (Permian), Santa Cruz Province, Argentina: systematic revision, biostratigraphy and palaeoecology. Alcheringa 36, 427–449. ISSN 0311-5518. The Permian lycophytes of the La Golondrina Formation (Santa Cruz province, Argentina) have remained unstudied for almost 50 years. This study reviews material described by Archangelsky in 1960 and increases the representation of specimens via new collections from the lower and middle members of the formation. The lycophytes, previously assigned to typical Laurasian genera, are re-analyzed and re-assigned to Gondwanan genera where appropiate. Two new lycophyte taxa, Bumbudendron patagonicum comb. nov. and Cyclodendron golondrinensis sp. nov. are proposed, and two specimens are retained under open nomenclature until better preserved material becomes available. Based on this study, the biostratigraphic range of Bumbudendron is extended to the Permian, whereas Cyclodendron remains a useful Permian stratigraphic index as previously suggested. Palaeoecological inferences derived from growth habit, floristic association and sedimentary facies indicate that these plants developed under micro- to meso-thermal, humid conditions.

BUMBUDENDRON VERSIFORME. A NEW LYCOPHYTE SPECIES FROM THE LATE PALEOZOIC OF ARGENTINA

Abstract Bumbudendron versiforme sp. nov. is described on the basis of imprints from the Agua Colorada Formation, Sierra de Famatina, Argentina. It is characterized by fusiform leaf cushions with a variable length-width ratio in a single stem. Megaspores are found associated with the lycopod remains. Comparisons with other species having infrafoliar bladders are made. The associated microflora suggests a Late Carboniferous age for this lycophyte species.

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.

Gymnosperm pollen grains from the La Veteada Formation (Lopingian), Paganzo Basin, Argentina: biostratigraphic and palaeoecological implications

ZAVATTIERI, A.M., GUTTIÉRREZ, P.R. & EZPELETA, M., January 2018. Gymnosperm pollen grains from the La Veteada Formation (Lopingian), Paganzo Basin, Argentina: biostratigraphic and palaeoecological implications. Alcheringa 42, 277–300. ISSN 0311-5518. This work forms the concluding part of a series of systematic studies of typical Gondwanan Permian palynofloras from the type section of the La Veteada Formation in the Paganzo Basin, central-western Argentina. It deals with the description and/or illustration of the non-taeniate monosaccate, bisaccate and polysaccate gymnosperm pollen species that are richly represented in the La Veteada Formation and are attributed to 25 genera. These taxa are allied to, or derived from, a diverse range pteridosperms (corystosperms, peltasperms), conifers (including Voltziales) and cordaites; Ginkgoales, Cycadales and Gnetales also have some representation. The new species, Jugasporites vellicoites, is instituted and the new combination, Alisporites angustus (Ouyang & Norris) comb. nov. et emend., is proposed. New evidence to support a Lopingian age for the palynoflora, considered to be the youngest Permian palynoflora recorded hitherto in South America, is based on a summary of the published information about its composition, together with an assessment of previous records of the diversity of gymnosperm taxa analysed in this contribution. The co-occurrence of several species of taeniate pollen (described in a previously published part of our work) and the gymnosperm taxa documented here, which have not been reported before from South America, differentiates the palynoflora of the upper La Veteada Formation from all others so far described from this continent. The high ratio of pollen versus spores, plus the botanical and palaeoecological inferences of the gymnospermous component of the formation’s palynoflora, reflects a parent vegetation adapted to relatively dry conditions. Such a low-humidity environment is consistent with the sedimentological evidence, which suggests that, through the Lopingian, semi-arid to arid climates dominated the southern South American basins. Ana María Zavattieri* (amz@mendoza-conicet.gov.ar) Unidad de Paleopalinología, Departamento de Paleontología IANIGLA, CCT-CONICET-Mendoza, Av. Adrián Ruiz Leal s/n, M5502IRA, Mendoza, Argentina; Pedro Raúl Gutiérrez (pedroraulgutierrez@gmail.com) Museo Argentino de Ciencias Naturales ‘B. Rivadavia’—CONICET, Sección Paleopalinología, Área Paleontología, Av. Ángel Gallardo 470, C1405DJR Buenos Aires, Argentina; Miguel Ezpeleta (miguelezpeleta@gmail.com) Centro de Investigaciones en Ciencias de la Tierra, Universidad Nacional de Córdoba—CONICET, Ciudad Universitaria, Av. Vélez Sarsfield 1611, X5016GCA Córdoba, Argentina.

First Record of Microforaminiferal Linings of the Early Pennsylvanian from the Chacoparaná Basin, Argentina

Abstract. The first record of microforaminiferal linings from the early Pennsylvanian of Argentina is presented as consisting of Trochospiral Type I, Planospiral Type II and cf. Uniserial indet. (sensu Stancliffe) forms while associated with acritarchs, prasinophytes, freshwater algae, spores and pollen grains. Microforaminiferal linings and associated microflora were obtained from the well core YCF.CO3 borehole (interval of 850–851.5 metres below drill floor), which comprises the lower part of the Ordóñez Formation (Chacoparaná Basin). This association documents the development of estuarine or shallow marine environments in the western part of the basin during the Pennsylvanian (Bashkirian?). The origin of these environments was associated with the final phases (transgressions) of the Carboniferous glaciation of Gondwana, documented in the diamictites of the Ordóñez Formation.