KIPUTZ IX: A UNIQUE ENSAMBLE OF RED DEER (CERVUS ELAPHUS LINNAEUS, 1738) FROM THE UPPER PLEISTOCENE OF THE IBERIAN PENINSULA. Kiputz IX is an upper Pleistocene site that has provided the richest set of Cervus elaphus complete remains in the Iberian Peninsula. This paper provides a metric and isotopic study of the postcranial skeleton of the 43 individuals that conform this tafocenosis. The robustness of the distal metacarpus evidences the existence of a clear sexual dimorphism and a small predominance of females respect to males. The stage of dental substitution makes evident that the sample is dominated by sub-adult and juvenile specimens, with a low proportion of juvenile and adult individuals. Application of a variability size index on a group of samples from the middle and upper Paleolithic in the Cantabrian Region do not allow establishing any osteometric relation with geographic and chronological factors. Variations in δ¹³C values among red deer and reindeer are related to the specialized consumption of different plant types. However, the gradual decline in red deer δ¹³C values over time may reflect the so-called ‘canopy effect’ impacting the floristic composition. Variations in the δ¹³C and δ¹⁵N values, studied together in red deer show that when climatic conditions were more temperate, humidity was higher in this environment than in de northern Pyrenees. The red deer sample from Kiputz IX constitutes a good basis for comparative studies of red deer populations from the Middle and Upper Pleistocene of Europe.

NANNOCONIDS OF THE MENDOZA GROUP (LOWER CRETACEOUS) NEUQUEN PROVINCE, REPUBLICA ARGENTINA: TAXONOMY, CRONOSTRATIGRAPHY AND PALEOGEOGRAPHIC SIGNIFICANCE. Late Jurassic-Early Cretaceous nannoconid assemblages are reported from 11 sections in the Neuquén Basin. Six species and 11 subspecies of Nannoconus Kamptner are studied systematically. Among them, Nannoconus kamptneri minor Bralower, Nannoconus kamptneri kamptneri Brönnimann, Nannoconus bucheri Brönnimann, Nannoconus circularis Deres and Achéritéguy and Nannoconus ligius Applegate and Bergen are highlighted as markers for the studied interval. Nannoconus elongatus minutus Van Niel, Nannoconus quadriangulus apertus Deflandre y Deflandre-Rigaud, Nannoconus truitti frequens Deres and Achéritéguy, Nannoconus truitti rectangularis Deres and Achéritéguy, Nannoconus truitti truitti Brönnimann are described for the first time in the Neuquén Basin. Nannoconus steinmannii minor Deres and Achéritéguy is reported for the first time in the Southern Hemisphere. The biostratigraphic analysis suggests an ampliation of the stratigraphic ranges of Nannoconus elongatus minutus, Nannoconus quadriangulus quadriangulus Deflandre and Deflandre-Rigaud, Nannoconus quadricanalis Bown and Concheyro, Nannoconus truitti frequens and Nannoconus truitti rectangularis. Changes in the composition and diversity of the recorded nannoconid assemblages suggest variations in the paleobiogeographic and paleoecological conditions that may be helpful in the characterization of the sedimentary environments represented in the Vaca Muerta and Agrio Formations.

The middle—late Eocene (45–36 Ma) dinoflagellate cyst distribution in high latitudes of the Southern Hemisphere has been explained by a surface ocean circulation pattern characterized by extensive subpolar gyres around Antarctica. Based on global paleoclimate models it has been proposed that these surface ocean gyres might favored the development of an Antarctic—endemic dinoflagellate cyst assemblage, which was consistently abundant until the end of the Eocene. During the late Eocene the deepening of the Tasman Gateway and the Drake Passage would have generated a circumpolar water flow responsible for the disruption of the local gyre system and the subsequent extinction of the endemic assemblage. Some authors have recently suggested that during the middle Eocene shallow water flows had already developed through incipient openings of the Tasman Gateway and the Drake Passage. In this review we have compared the middle Eocene dinoflagellate cysts assemblages dominated by the Antarctic—endemic species from localities of the Drake Passage area and performed a multivariate analysis to evaluate this hypothesis. Our results point out a clear differentiation between localities to the north and south of what now is the Drake Passage. While localities from the Antarctic Peninsula and Scotia Sea would had been affected by Antarctic surface waters, the Austral Basin would had been flooded by Antarctic waters together with Pacific waterflows developed through an incipient Drake Passage during the middle Eocene.

HOLOCENE PALEOENVIRONMENTAL RECONSTRUCTION OF THE MAR CHIQUITA COASTAL PLAIN (BUENOS AIRES PROVINCE, ARGENTINA) BASED ON DIATOMS. Diatom assemblages from a core at the north of Mar Chiquita coastal plain were analyzed in order to identify environmental changes due to salinity and depth. The core contains sediments dated at the base in 5802±70 ¹⁴C years BP. Four lithological units were defined: greenish-grey silt, brownish-grey sandy silt, heterolithic facies and brown sandy silt. Two hundred diatom species were identified and grouped based on their salinity tolerances and life form. Cluster analysis defined two diatom zones. The lower section of the sedimentary sequence (from the base to 90 cm depth, Zone I) was dominated by Paralia sulcata (Ehrenberg) Cleve and Psammococconeis cf. disculoides (Hustedt) García accompanied by marine-brackish plankton, epipsammon and epiphytes indicating coastal marine conditions. From 90 cm towards the top (Zone II), salinity and depth decrease: P. sulcata decline and appear Planothidium delicatulum (Kützing) Round and Bukht (brackish) and Hippodonta hungarica Grunow (brackish freshwater taxa), benthic and epiphytes diatoms increased. Multidimensional Scaling Analysis (MDS) showed that fossil diatom assemblages were similar to the modern assemblages from the inlet of Mar Chiquita coastal lagoon. These new diatom and sedimentological data support the regional model for the Holocene sea-level fluctuation and allow inferring the existence of a marginal coastal system during the regressive phase that evolved into a brackish-freshwater coastal lagoon and marsh.

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.

PALYNOSTRATIGRAPHY OF SALTO DEL MACHO FORMATION, PALEOGENE OF THE ÑIRIHUAU BASIN, ARGENTINA. The complete record of the palynomorphs from the Salto del Macho Formation (Paleogene) is presented from its type locality at the Foyel River section, Ñirihuau Basin Andean area, Argentina. Elements of continental and marine origin were identified: a total of 109 species corresponding to Bryophyta, Lycopodiophyta and Polypodiosida spores, Gymnospermophyta and Magnoliophyta (Angiospermae) pollen grains, continental algae and marine organic-walled microplankton. The stratigraphic distribution of sporomorphs recognized in the Salto del Macho Formation at other Paleogene—early Neogene (Miocene) basins from Patagonia argentina, Chile and Antarctica is presented. The presence of Echitriporites trianguliformis form A Müller et al., Psilatricolpites minutus González Guzmán, and Myrtaceidites parvus form nesus Cookson and Pike at the Salto del Macho Formation represents the first record of these species in Argentina. An age comprised between middle Eocene and early Oligocene is here suggested for this unit, on the basis of data yielded by palynological markers and palynostratigraphic and multivariate analyses.

PALMOXYLON ROMEROI SP. NOV., OF THE CHIQUIMIL FORMATION (UPPER MIOCENE) FROM VALLE DE SANTA MARÍA, CATAMARCA PROVINCE, ARGENTINA. Diverse palms types and other angiosperms represented by pollen records, fossil wood and leaf, stems and fruit impressions, have been found and studied in the Chiquimil Formation (upper Miocene) of the Santa María Group. In this contribution a new species of fossil Arecaceae is described, i.e., Palmoxylon romeroi sp. nov. It is represented by a silicified fossil palm trunk found in the Chiquimil Formation in Catamarca, northwestern Argentina. The fossil material has a Cocos-Type general stem structure; central cylinder well delimited from the cortical zone; fibrous-vascular bundles with vaginata shape; metaxylem usually with 3–5 vessels; one phloem strand; tabular, radiating and paravascular parenchyma present; ground parenchyma composed by spheroid to elongated cells, lobed with a rectangular shape and globular echinate stem stegmata. This taxon most closely compares to the Subfamily Coryphoideae, tribe Cryosophileae. Considering the distribution of most closely related extant taxon and the geological and paleobotanical records, Palmoxylon romeroi sp. nov. probably grew in savannah-like uplands characterized by a dry or seasonally dry tropical-subtropical climate.