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Copyright of Documenta Praehistorica is the property of Documenta Praehistorica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper describes a petrified trunk collected from a conglomerate bed of the Springhill Formation (Berriasian-Valanginian) in the Estancia El Álamo locality, Santa Cruz Province, Argentina. The fossil trunk is classified within the ubiquitous genus Agathoxylon and the wood anatomy shows a close affinity to that of Araucariaceae. This Patagonian wood has a distinct combination of anatomical characteristics unique among all known species from the Jurassic and Cretaceous of Western Gondwana allowing to diagnose a new fossil taxon Agathoxylon mendezii sp. nov. Sedimentological and megafloristic proxies of the Springhill Formation suggest that Agathoxylon mendezii sp. nov. grew under a warm and wet climate, which indicates a subtropical to temperate palaeoenvironment. However, the large number of frost rings in the earlywood of this araucarian tree suggests that the palaeoenvironment at Estancia El Álamo was subjected to recurrent disturbances, most likely caused by regional continuous volcanic activity originating from volcanoes located far away to the west. This activity would have produced periodic stratospheric veils that promoted rapid decreases in surface air temperature; the wood response to such stressful conditions would have been the formation of numerous (at least five) frost rings. Although recurrent eruptions in Patagonia during the Early Cretaceous are well recorded, this study is the first to register eruptions recorded in a coniferous wood. [ABSTRACT FROM AUTHOR]

The Patagonian coast has been occupied at least since the Middle Holocene but the way in which humans have interacted with spaces and resources in different areas of the coast has varied. As such, it is important to study the specifics of each occupation. In this paper, the activities that would have taken place at Cabeza de León 1 archaeological site, Monte León National Park, Santa Cruz province, Argentina, are addressed from the study of the recovered lithic assemblages. Results show the use of local raw material, the development of all manufacture stages in situ and the implementation of mainly expedient strategies. It can also be inferred that activities were mostly related to the capture and processing of resources. La costa patagónica ha sido ocupada desde mínimamente el Holoceno medio, pero el modo en que los humanos interactuaron con el espacio y los recursos a lo largo del tiempo en los distintos sectores fue diferente, lo que hace necesario estudiar las particularidades de cada ocupación. Aquí se abordan las actividades tecnológicas que se habrían desarrollado en el sitio Cabeza de León 1, sito en el Parque Nacional Monte León (Santa Cruz, Argentina), a partir del estudio de los materiales líticos allí recuperados. Estos muestran el empleo mayoritario de materias primas locales, la realización de todas las etapas de manufactura in situ, la implementación de estrategias tecnológicas principalmente expeditivas, y también permiten inferir actividades mayoritariamente vinculadas a la captura y procesamiento de recursos. [ABSTRACT FROM AUTHOR]

Copyright of Boletín de la Sociedad Argentina de Botánica is the property of Sociedad Argentina de Botanica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this paper, the analysis of a radiocarbon database of the North Coast of Santa Cruz (central Patagonia, Argentina), is presented. Dated archaeological samples were obtained from 56 different types of archaeological sites (open-air -residential sites and burials-, and also rock shelters). The objective of this paper is assessing the continuities and discontinuities in the chronological signal of the area and identifying tendencies along the Holocene. The database currently contains 75 radiocarbon dates falling between ca. 8000 and 300 BP. The radiocarbon data base provides information on the chronological, spatial and contextual variability of the archaeological record of North Coast of Santa Cruz. By means of different analysis of sum of probabilities, we present three different chronological moments of human use of the coast and intermediate zone can be identified. A first moment is represented by early evidence of settlement during Middle Holocene. A second moment corresponds to a hiatus between ca. 5800 and ca. 3900 BP without archaeological evidence. Finally, a third moment is where an increasing of chronological signal occurred, related to greater artifactual variability and an increase in the intensity of human settlement in the Patagonian region. The causes that could have influenced in the discontinuity of the chronological signal of the study area, and the characteristics of the different moments identified are discussed. [ABSTRACT FROM AUTHOR]

Copyright of Intersecciones en Antropología is the property of Universidad Nacional del Centro de la Provincia de Buenos Aires, Facultad de Ciencias Sociales and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract: This paper compares two zooarchaeological sub-samples, each of which comes from a different area (North chamber and South chamber) of Maripe Cave Site (Santa Cruz, Argentina). In previous papers, each chamber was interpreted as a particular microenvironment based on their specific environmental and geoarchaeological features. In both areas, hunting–gatherer society occupations were recorded since the Pleistocene–Holocene transition to late Holocene. This paper investigated and discussed the different agents and processes involved in the formation of each assemblage, with the aim of assessing the taphonomic variability between the two areas and discussing their integrity. Bone specimens of Lama guanicoe (guanaco), the most common species on the site, were analyzed. The bone surfaces of specimens were studied by naked eye observations and binocular magnifying to 10×, which allowed recognition of different patterns of modification. The representation of guanaco anatomical units was also discussed at each chamber according to economic utility and BMD values. The results indicate that while there was involvement of different natural agents and processes acted differently in each sector, the main accumulating agent in both sets was human. Differences between both chambers are observed in the representation of anatomical units, in processing marks, in the conservation of specimens, and in the number and intensity performed by each natural agents and process in each sector. Each chamber indicates a different taphonomic history: the North Chamber records greater conservation and archaeological integrity, while the South Chamber shows a more complex taphonomy. [Copyright &y& Elsevier]

Abstract: In the Deseado Massif there are many stratified archaeological sites located in caves and rockshelters. The cultural sequences, proposed in the past century, include an occupational hiatus and cultural changes that were developed on the basis of large tools from archaeological sites, without debitage analysis. The aim of this paper is to review the current debate on lithic technology and human occupations of this area during the Mid-Holocene, integrating new data, as well as the latest environmental interpretations. The contribution of new information from blade and bifacial technologies is central to discussion of the models proposed by other authors. The new baseline information generated in the last decade, allow original interpretations. The evidence of coexistence between blade and bifacial technologies during the Mid-Holocene constitutes the main contribution of this paper. [Copyright &y& Elsevier]

This paper reports the pollen sources selected by Apis mellifera in the area northwest of Santa Cruz (Argentina). It evaluates the relative biomass contribution and the protein content of the collected taxa. During the apicultural period (September 2008-March 2009) pollen loads from three colonies were collected every fortnight using pollen traps. Forty-two pollen types were found in the samples, from which 15 taxa had a biomass contribution over 1% of the total pollen crop. The main pollen sources were Brassicaceae, Taraxacum officinale, Convolvulus arvensis, Rosaceae, Salix spp. and Schinus marchandii (Anacardiaceae). Of the total pollen sources identified, 15 are new records for the bee pollen flora of Argentina and 13 are native plants of South America. The contribution of native flora occurred mainly in spring. Schinus marchandii, Mulguraea-Junellia type (Verbenaceae), Adesmia spp. (Fabaceae), Sysirinchium spp. (Iridaceae), Acaena spp. (Rosaceae), Astereae and Senecio spp. (Asteraceae) were the indigenous pollen types with the highest biomass contribution. Protein content of most collected pollen types was variable (between 13.25% and 24.43%). [ABSTRACT FROM AUTHOR]

Well-preserved and diverse Early Cretaceous palynological assemblages were studied from an outcrop section of the Springhill Formation at the Río Correntoso locality (PRC), close to Ghío Lake, in Santa Cruz Province, Patagonia, Argentina. The studied log corresponds to the northernmost outcrops known for the Springhill Formation in the Austral Basin. Most of the palynomorphs algae (Botryococcus, Sphaeroplea, Lecaniella, Zygnema, Pseudoschizaea, Schizosporis, Ovoidites), and some angiosperm pollen grains (Proxapertites , Longapertites, Arecipites) are distinctive and characterize the palaeoenvironment and palaeoclimate of PRC, which was dominated by estuarine coastal margin sedimentites deposited under warm and humid conditions. These angiosperm pollen grains correspond to the earliest record of these group in Patagonia, represented by diverse monosulcates and one rare tricolpate type. This new record of angiosperm pollen in the Springhill Formation provides further evidence that one of the earliest diversifications of angiosperms started at least during the early Cretaceous in Patagonia. Sergio Archangelsky provided an invaluable expertise in the field of paleobotany in multiple ways. His knowledge transcended not only through his papers but also through his exceptional oratory skills. His talks were always enriching in every aspect, combining an engaging historical account with a vision towards the future. "...La paleobotánica un placer, debe ser algo agradable, es decir uno cuando trabaja en paleobotánica le gusta lo que hace, y cuando uno está describiendo, uno se va, y es lo mismo que componer una pieza musical, te perdés, te perdés en todo y lo hacés con gusto, con pasión..." "...The paleobotany is a pleasure, it should be something enjoyable, meaning that when you work in paleobotany, you love what you do. And when you're describing, you get lost, just like composing a musical piece. You lose yourself, in everything, and you do it with pleasure, with passion...". The file with the voice of Sergio Archangelsky is in Supplementary file under Sergio_Archangelsky.mp3. • The palynoflora of the Springhill Formation includes algae and land plants. • Pollen records show features of early members of some taxa (monocots and eudicots). • Angiosperm pollen grains provides evidence for early radiation of some basal taxa in Patagonia. • Palynoflora studied indicates freshwater palaeoenvironment, warm and humid climate. [ABSTRACT FROM AUTHOR]

Southern Patagonia contains several Eocene fossiliferous deposits that have only been superficially explored and studied. One of these corresponds to the La Marcelina Formation with outcrops in the south-western slope of the Deseado Massif, Santa Cruz Province, Argentina. No detailed palynological studies have been performed so far in this unit. Here we estimate the age, palaeoenvironment, and climatic conditions based on the analysis of terrestrially derived spores, algae cysts, and pollen grains. The recovered association supports an Eocene age and concurs with a mixed flora, including Gondwanan and Neotropical elements, dominated by Podocarpaceae, Nothofagaceae, and Proteaceae, and that probably developed under a temperate and humid climate. Overall, these results expand our understanding of the composition of Eocene floras from the highest latitudes of South America, as well as provide new evidence of past paleoclimates for the area. [ABSTRACT FROM AUTHOR]

The archaeological record of the Province of Santa Cruz's north Atlantic coast in Argentine Patagonia is represented mainly by middens. These shell middens are made up of the calcareous exoskeletons of mollusks, as well as skeletal remains of vertebrate fauna, lithic artifacts, and carbonized plant remains, intermixed with a varying quantity of sedimentary soil. Recently, along the Lower Basin of the Deseado River, outcrops have been identified that would have functioned in the past as rock shelters for hunter-gatherers who occupied the area during the Middle and Late Holocene. With the aim of expanding our knowledge concerning the dynamics of use of coastal spaces, we began a stratigraphic study of the shell middens and rock shelters. Here, we present a comparative analysis of the occupation characteristics registered at both types of sites and their possible structuring in terms of mobility and functionality. Rock shelters would have functioned primarily as contexts for short-term activities related to the processing and consumption of fauna, mainly terrestrial and to a lesser extent marine fauna. These probably structured seasonal mobility strategies that linked coastal shell middens, defined as multiple activity contexts, with hinterland areas that might have been related to the specific pursuit of other activities. [ABSTRACT FROM AUTHOR]

HMS Swift was a British sloop of war which sank in Patagonia - South Atlantic Ocean - in 1770. The wrecksite was discovered in 1982 by local divers from Puerto Deseado, Santa Cruz Province, Argentina, and this find originated the development of underwater archaeology in the country. The article presents a comprehensive review of the various research strands addressed throughout many years, and it also reflects on the legacy that the site and the project represents for topics other than archaeology, such as heritage management, museology, and cultural industries. [ABSTRACT FROM AUTHOR]

The aim of this paper is to generate new data on raw material sourcing of multiple activities sites at La Primavera locality to describe some provisioning strategies adopted by mobile hunter–gatherer societies, and contribute to the study of the local settlement in the wider regional context. The local structure of lithic resources is characterized; the natural distribution of useful rocks is modeled and the raw materials of artifacts from multiple activities sites are sourced. The classification and sourcing technique applied is not a determinant method, but a preliminary approach adequate to deal with a very large lithic artifact sample. The rock distribution across the landscape was analyzed using a Geographical Information Systems (GIS) for compiling the available data and estimating the distances from the sites to the sources for each raw material found in them. Based on the circulation distances and different considerations regarding the characteristic of the lithic sources, three different provisioning strategies are delineated. They suggest that settlement at the locality involved a certain permanence time that surpasses a logistic use, while keeping trade and social networks with other localities in the regional context. [ABSTRACT FROM AUTHOR]

This paper discusses provisioning strategies of lithic raw materials at Maripe Cave site (province of Santa Cruz, Argentina). The archaeological sequence represents different moments of human occupation at the cave and in the study area, which show different lithic technologies. The morpho-typological analysis of the lithic cores recovered contributes to our knowledge about the strategies related to procurement and provisioning of the lithic raw materials used for artifacts production. We identified different raw materials from the analyses of lithic cores and other artifacts from the site. This allowed analyzing trends in selection and provisioning processes and interpreting the mobility strategies of the groups that inhabited the Deseado Massif since the Pleistocene–Holocene transition. Trends suggest that, during the Pleistocene–Holocene transition and early Holocene, abandoned cores from Maripe Cave mainly indicate people provisioning strategies. During middle Holocene, the cores shows blades extractions and raw material use from long distance, discarded with remaining potential utility. Finally, at late Holocene the cores were mainly prepared for blade extractions. Our results do not fully agree with Kuhn's proposal, probably due to both the theoretical polarization between the provisioning strategies and the palimpsest effect. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to begin to understand human mobility through rock transport at different times in two areas with different environmental characteristics: the Southern Deseado Massif and the basaltic canyons north of the Santa Cruz River. We focus on obsidian, which has a clear geochemical signature and an uneven distribution. Additionally, we use macroscopic information on siliceous rocks, which at present have only been identified in northern areas, although they may also be recovered randomly and in low frequencies in southern ones. During the initial peopling of the Southern Deseado Massif (ca. 10,800 BP), inhabitants were transporting black obsidian as well as translucent chalcedony, probably as part of the individual gear. During the Late Holocene, the number of obsidian artifacts decreased in the Southern Deseado Massif, related to a better knowledge of the high-quality local lithic resources and/or to the existence of higher population densities. Obsidian artifacts are more abundant in the northern Santa Cruz River basin than in the southern Deseado Massif, suggesting the existence of a relationship with areas located to the northwest, close to the obsidian source, as other lines of evidence suggest. In addition, the presence in the basaltic canyons of artifacts made from high-quality siliceous rocks, more abundant and predictable in northern areas, could also be the result of human movements following a north-south direction. [ABSTRACT FROM AUTHOR]

Lithic resources at the Central Plateau of Santa Cruz (Argentina) are abundant, ubiquitous and of very good quality for knapping. They have been exploited by hunter–gatherer societies since the latest Pleistocene until the Late Holocene. The study of their distribution, availability, and ways of exploitation at the quarries, together with the information stemming from the archaeological sites, enable the understanding of the first stages of tool production and consumption. In this paper, two quarries from La María Archaeological Locality (Cantera de Sílex de CDM and Cantera Bosque Petrificado) are studied and compared. Their geomorphologic location is described. The lithological characteristics of the outcrops, the size of the stones, and the variability of raw materials available at them are also addressed. The accessibility and visibility of the quarries are analyzed. The way raw materials were exploited at the sources is evaluated taking into consideration their relationship with the local and regional structure of lithic resources. The information generated for the quarries is complemented and compared with the local trends identified for the habitation sites. This enabled the formulation of a general model about the first stages of production. Although the quarries have different types of raw materials (flint and silicified wood), results show that similar technological strategies were implemented in them. These are in agreement with the general trend at the local and regional levels. Both sources are easily accessible from the surrounding landscape. They are visible from nearby areas. Probably, they were exploited mainly from nearby sites. At the quarries, the first stages of tool production were performed: core decortication and preparation and the production of blanks. The acquisition of raw material involved the selection of good quality nodules and boulders and the production of polyhedral cores knapped in multiple directions. These cores could be transported to the habitation sites or could be discarded in situ while still presenting active platforms. On the other hand, differences in some procurement practices might be related to decisions and variations linked to the particular characteristics of the resources in both outcrops. [ABSTRACT FROM AUTHOR]

The upper member of the Río Turbio Formation is a well-exposed marine Eocene unit at high latitudes in Patagonia, Argentina. It holds important information helpful to reconstruct regional climate and oceanographic patterns in an area adjacent to the Drake Passage. Knowledge on the paleoenvironmental and paleoceanographic evolution of the southwestern Atlantic Ocean during the Paleogene is hindered by the lack of precise tools to date and correlate the sedimentary units. In this paper we present the dinoflagellate cyst assemblages from the upper member of the Río Turbio Formation and compare the stratigraphic distribution of their species with the ranges proposed in the Paleogene Southern Pacific Ocean dinoflagellate cyst zonation. The abundance of Enneadocysta dictyostila , the first occurrence of Impagidinium parvireticulatum and the presence of Vozzhennikovia apertura all allow us to propose a mid-Lutetian to mid-Priabonian age (44.6 to 34 Ma) for the upper member of the Río Turbio Formation. The study section is characterized by a middle Eocene endemic-Antarctic dinocyst assemblage. According to the dinocyst assemblages the analyzed section can be divided into four zones. Zone I is dominated by E. dictyostila , which points to a distal setting in an inner shelf environment. Zone II exhibits a high abundance of V. apertura , thus suggesting high trophic levels and cool waters in a shallow-marine, coastal environment. Zone III is dominated by I. parvireticulatum and a lower abundance of E. dictyostila , both species indicating a possible deepening of the depositional area with increasing influence of oceanic waters. Finally, Zone IV is dominated by V. apertura , indicating shallow marine waters. Our data suggest that V. apertura could have been produced by a stress-tolerant dinoflagellate species. Toward the top of the section, the samples are dominated exclusively by sporomorphs and zygospores of fresh-water green algae, which indicate a transition from a tide-dominated deltaic to a continental environment. [ABSTRACT FROM AUTHOR]

Copyright of Intersecciones en Antropología is the property of Universidad Nacional del Centro de la Provincia de Buenos Aires, Facultad de Ciencias Sociales and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Megaraptora is a theropod clade known from former Gondwana landmasses and Asia. Most members of the clade are known from the Early to Late Cretaceous (Barremian–Santonian), with Maastrichtian megaraptorans known only from isolated and poorly informative remains. The aim of the present contribution is to describe a partial skeleton of a megaraptorid from Maastrichtian beds in Santa Cruz Province, Argentina. This new specimen is the most informative megaraptoran known from Maastrichtian age, and is herein described as a new taxon. Phylogenetic analysis nested the new taxon together with other South American megaraptorans in a monophyletic clade, whereas Australian and Asian members constitute successive stem groups. South American forms differ from more basal megaraptorans in several anatomical features and in being much larger and more robustly built. [ABSTRACT FROM AUTHOR]

Predicted warmer temperatures and more frequent extreme climatic events in the southern Andes may affect the dynamics of the Patagonian forests. These environmental changes may differentially alter the probability of Nothofagus pumilio establishment across its altitudinal range of distribution. We monitored fruit fall, seedling emergence and survival at altitudinal distribution range of N. pumilio forests in Santa Cruz (49°22′ S—72°56′ W), Argentina. Fruit fall, seedling emergence and survival were tested in relation to drought, based on the SPEI (Standardized Precipitation Evapotranspiration Index), interacting with elevation. Fruit fall was consistently higher at low elevation and the abundance of fruits was not affected by drought intensity. Density of new-born seedlings was ~ 9 to 24 times lower at low- than at high-elevation plots in our first observations (2014 and 2016), characterized by warm-dry climatic conditions in spring-early summers. In contrast, seedling abundance was ~ 1.5 times larger at low elevations during relatively cold-wet growing seasons. Survival probability was explained by the interaction between SPEI and elevation. At low elevation and in dry periods, survival probability was lower (CI 54–72%) than in wet periods (CI 68–84%) but at high elevation similar survival was registered even with positive or negative SPEI values. Our results show interacting effects of elevation and drought on tree establishment at the elevation limits, with positive and negative drought effects at high and low elevations, respectively. Predicted increase of extreme drought events during the XXI century could be detrimental for N. pumilio establishment at dry, low-elevation forests. [ABSTRACT FROM AUTHOR]

Abstract: This paper describes the reconstruction of the previously undocumented Meseta Cuadrada palaeo ice cap on south-west Meseta del Lago Buenos Aires, Santa Cruz Province, Patagonia. Based on theoretical surface profiles the reconstruction of the Meseta Cuadrada Palaeo Ice Cap indicates an ice mass covering at least 78km2 with a total ice volume around 9.2km3. The inferred equilibrium line altitude (ELA) of the palaeo ice cap (2031m asl) represents a drop of 286m compared to the ELA of the current Meseta Cuadrada glacier (~2317m asl). We explain this small change in ELA with reference to the flat hypsometry of the palaeo ice cap and an enhanced aridity to the west of the Patagonian Andes caused by the existence of the Last Glacial Maximum (LGM) Patagonian ice sheet. Calculated annual accumulation values of ca. 402 to 957mm/a at the ELA of the Meseta Cuadrada palaeo ice cap derived by a degree day model (DDM) during the last local glacial maximum extent are low compared with estimations of the current accumulation at the ELA of the remaining glacierized area of around 3789mm/a. This strongly supports the existence of increased aridity and seasonality east of the Patagonian Andes during the Last Glacial Maximum, provided both maximum extents were synchronous. [Copyright &y& Elsevier]

Se-bearing polybasite- Tac is associated with galena, chalcopyrite, sphalerite, tetrahedrite, electrum and quartz at the Martha mine, an epithermal silver–gold deposit located adjacent to the Deseado Massif, Santa Cruz province, Argentina. Three samples, with variable chemical composition and showing the 111 unit-cell type, were studied by means of X-ray single crystal diffraction and electron microprobe. The unit-cell parameters were modeled using a multiple regression method as a function of the Ag, Sb, and Se contents. The predicted values resulted in excellent agreement with experimental unit-cell parameters. We observed that high contents of selenium in polybasite are associated with relatively low copper contents. This finding corroborates previous studies that the copper content of pearceite–polybasite group minerals can be very low if selenium is present. [ABSTRACT FROM AUTHOR]

Egg laying is one of the most important phases in a female bird's breeding cycle. Its cost is high because eggs contain all the resources needed for the development of an embryo. Variation in size and quality of eggs can have important long‐term consequences for offspring survival. Hatching asynchrony is known to influence sibling competition in many bird species. Last‐hatched chicks will have a competitive disadvantage throughout the pre‐fledgling period because they are smaller. The aim of this study was to analyze the effect of hatching asynchrony and egg size variation on the growth and fledging success of Magellanic penguin Spheniscus magellanicus chicks after disentangling the effects of parental condition. We simultaneously manipulated egg size dimorphism, hatching asynchrony and parental condition by performing a cross‐fostering experiment, creating broods with controlled egg size dimorphism and hatching asynchrony in a colony of Magellanic penguins located in Isla Quiroga, Santa Cruz, Argentina. We found that hatching asynchrony had a negative effect on last‐hatched chicks, but this disadvantage was mitigated by egg size dimorphism in their favor. Moreover, females in good condition invest more in second than in first chicks, which, added to a greater investment by foster fathers, leading to offspring fledging in good condition. On the contrary, for the first‐hatched chicks, we found that body condition of the biological father was an important factor for their growth. We conclude that raising more than one chick seems to be a decision based on parental condition throughout the breeding season. [ABSTRACT FROM AUTHOR]

The Late Cretaceous dinosaur record in southern South America has been improved recently; particularly with findings from Chorrillo and Cerro Fortaleza formations, both bearing ankylosaur remains, a clade that was not previously recorded in the Austral Basin. The dinosaur fauna of the type locality of Cerro Fortaleza Formation is known from -and biased to- large-sized sauropod remains and a single described taxon, the titanosaur Dreadnoughtus schrani. Here, we report the taxonomic composition of a site preserving thirteen isolated teeth and several osteoderms belonging to three dinosaur clades (Abelisauridae, Titanosauria, and Nodosauridae), and at least one clade of notosuchian crocodyliforms (Peirosauridae). They come from sediments positioned at the mid-section of the Cerro Fortaleza Formation, which is Campanian-Maastrichtian in age, adding valuable information to the abundance and biodiversity of this Cretaceous ecosystem. Since non-titanosaur dinosaur bones are almost absent in the locality, the teeth presented here provide a window onto the archosaur biodiversity of the Late Cretaceous in southern Patagonia. The nodosaurid tooth and small armor ossicles represent the first record of ankylosaurs for this stratigraphic unit. The peirosaurid material also represents the most austral record of the clade in South America. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Raptor Research is the property of Raptor Research Foundation and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Applied Ecology is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Raptor Research is the property of Raptor Research Foundation and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This is an integrative study of a potential zoonotic digenean from the Magellanic Southwestern Atlantic coast. The life cycle of the gymnophallid Gymnophalloides nacellae Cremonte, Pina, Gilardoni, Rodrigues, Chai and Ituarte, 2013 (Digenea) at the type locality, Puerto Deseado (47° 45′ S, 65° 51′ W), Santa Cruz province, was elucidated. This digenean uses the upper subtidal clam Gaimardia trapesina (Lamarck) (Gaimardiidae), which lives on the fronds of the giant kelp, as first intermediate host. A very short-stem furcocercous cercaria emerges and enters the limpets, Nacella magellanica (Gmelin) and N. deaurata (Gmelin) (Nacellidae), which live in the lower rocky intertidal zone. The unencysted metacercariae inhabit the extrapallial space of the limpet at high prevalences and intensities of infection. When the black oystercatcher Haematopus ater Vieillot and Oudart (Charadriidae) preys upon it, it becomes infected, acting as the definitive host. This parasite seems to exhibit a high specificity for their first and second intermediate hosts. Its geographical distribution is from 47 to 55° S in Patagonia, and it is restricted to those sites where the giant kelp reaches to lower intertidal and upper subtidal zones where the limpets are present. Gymnophalloides seoi Lee, Chai and Hong, 1993, a parasite of the Pacific oyster Magallana gigas (Thunberg) (Ostreidae), causes a zoonotic disease in Korea; thus, G. nacellae represent a risk of being a zoonotic parasite if infected limpets are consumed. [ABSTRACT FROM AUTHOR]

Here I describe and illustrate 19 leaf morphospecies from the Paleogene Río Turbio Formation, Santa Cruz Province, Argentina. They were referred to the extant tropical and subtropical families Lauraceae (9 morphospecies), Malpighiaceae (1 morphospecies), Vitaceae (2 morphospecies), Anacardiaceae (2 morphospecies) and Sapindaceae (5 morphospecies). These taxa were recorded throughout the unit, but they are more abundant in the lower member of the Río Turbio Formation. The observed decreasing trend in megathermal taxa throughout the unit indicates the beginning of the flora turnover that characterized Patagonian ecosystems from the Late Eocene onwards and it is in agreement with the marked global cooling trend of the terminal Paleogene. [ABSTRACT FROM AUTHOR]

Southern Patagonia's landscape hosts several semi-natural habitats, traditionally used for sheep production, such as Mulguraea tridens and Lepidophyllum cupressiforme scrublands. Mulguraea scrublands are managed via mechanical shredding to remove shrubs and increase grass availability, alternating with structural-retention strips. We analyzed the influence of structural-retention management (with cut and retention strips) in Mulguraea scrublands with regards to above-ground arthropod community structure, as well as differences between the two natural scrubland types. We worked in Santa Cruz Province (Argentina) with pitfall traps during two summers in the first 2 years after mechanical shredding. Richness, abundance, occurrence frequency, Shannon-Wiener diversity and Pielou evenness indices, and similarity among assemblages were evaluated using univariate and multivariate statistical tests. Complementarily, we described vegetation ground cover and microclimate. We collected 3279 individuals from 38 species belonging to Insecta and Arachnida Classes. Shannon-Wiener diversity and Pielou evenness indices, as well as the overall assemblages, differed significantly between managed cut strips and natural Mulguraea scrublands, mainly due to the loss and introduction of species from surrounding environments; abundance also differed in the first sampling year compared to the second year. Likewise, managed retention strips allowed the partial maintenance of arthropod community structure and had a microclimate that was similar to natural Mulguraea scrublands, although assemblages in managed cut and retention strips became more similar among themselves in the second sampling year. On the other hand, richness, abundance and assemblage of both natural scrubland types differed significantly, with 87 % more indicator species in Mulguraea than in Lepidophyllum scrublands. Greater dissimilarity occurred between both natural scrubland types in dryer years, which could be related with an El Niño Southern Oscillation event. If arthropod community structure changes prove stable over time, mechanical shredding with structural-retention management would allow for an increase in the sheep carrying capacity, while reducing impacts to the arthropod community, thus providing a viable compromise between productivity and conservation in a fragile arid environment. More studies are necessary to evaluate long term changes in above-ground arthropod community structure of scrublands in arid zones of southern Patagonia. [ABSTRACT FROM AUTHOR]

Myrtaceae, the gum tree family, is a large angiosperm clade of 5671 species mostly distributed in tropical and subtropical regions of the world. In the southernmost tip of South America (Santa Cruz province) where the fossils analysed in this study come from (Río Turbio Formation), this family is virtually absent and the extant vegetation is largely dominated by deciduousNothofagus pumilioandNothofagus antarctica. During the early Paleogene, however, the Myrtaceae were an important element in southern Patagonian floras. Here, we report and describe ten taxa related to the extant generaEugenia,Myrcia,Psidium,Myrcianthesand possibleEucalyptusandCampomanesia. The presence of a high diversity of Myrtaceae during the Eocene in one of the southernmost regions of the world could be thought as unusual. However, during this period of time (45 Ma), a number of other tropical lineages also reached these high latitudes probably as a consequence a warming climatic trend. In fact, through the Paleocene–Early Eocene interval, climatic conditions were the warmest of the Cenozoic. After this period of time, a progressive decline in temperature forced the migration of megathermal elements towards lower latitudes and, at the same time, led to the expansion of forest dominated byNothofaguswhich predominate the region today. [ABSTRACT FROM AUTHOR]

Here we report multiple lamniform shark teeth recovered from fluvial sediments in the (Campanian-Maastrichtian) Cerro Fortaleza Formation, Santa Cruz Province, Argentina. This small tooth assemblage is compared to various lamniform sharks possessing similar dental morphologies, including Archaeolamna, Cretalamna, Dwardius, Dallasiella, and Cretodus. Although the teeth share numerous morphological features with the genus Archaeolamna, including a developed neck that maintains a relatively consistent width along the base of the crown, the small sample size and incomplete nature of these specimens precludes definitive taxonomic assignment. Regardless, the discovery of selachian teeth unique from those previously described for the region broadens the known diversity of Late Cretaceous South American sharks. Additionally, the discovery of the teeth in fluvial sandstone may indicate a euryhaline paleobiology in the lamniform taxon or taxa represented by this tooth assemblage. [ABSTRACT FROM AUTHOR]