Negro Province Research Articles

Epidemiology, diagnosis, treatment and follow-up of cystic echinococcosis in asymptomatic carriers.

Río Negro Province is endemic for cystic echinococcosis (CE). A CE control program includes early diagnosis in humans. During 1980-1996, screening was done with serology and surgery was the unique choice of treatment. Since 1997, ultrasound (US) has been the method of choice for screening, and new choices of treatment for asymptomatic carriers are discussed in the CE guidelines. Between 1997 and 2016, 42 734 abdominal USs were performed, 192 new asymptomatic cases were diagnosed and underwent a protocol according to the size, location and type of cyst. Treatment options included active surveillance (US monitoring, 83 [43.3%]), antiparasitic (albendazole, 92 [47.9%]) and surgery (17 [8.8%], including percutaneous treatment). After 7.7 y of follow-up, of the cases under active surveillance, 28 (33.7%) had to change treatment: 5 (6%) to surgery and 22 (26.5%) to albendazole. Of the patients treated with albendazole, 3 (3.2%) were operated on and 13 (14%) were treated with a second cycle of albendazole. As a result of the present study, resolution of CE in a non-surgical way with albendazole is confirmed to be effective in asymptomatic carriers with CE1 or CE3a cysts. An update eliminates the strategy of active surveillance in type CE1 cysts <3 cm and is replaced by treatment with antiparasitic in all asymptomatic cases with CE1 or CE3a cysts <10 cm. The update also limits follow-up to 12-18 months to evaluate those cases with non-response to antiparasitic and switch to a surgical option.

Study of a New Population of the Argentinian Endemic Species Riella choconensis Hässel (Riellaceae, Marchantiophyta) Reveals a Novel Anatomical Structure of the Female Involucre in Riella

A new population of the Argentinian endemic Riella choconensis Hassel (Riellaceae, Marchantiophyta) was discovered from a culture of sediments from the Laguna de los Juncos (Rio Negro province, Argentina). This species was known previously from two nearby collections, made in 1984, in the type locality at the Ramos Mexia reservoir (Neuquen province) and was not recorded since. Fresh material from the new population enabled detailed morphological analyses, which are extensively described here, illustrated and compared to type material of the species. Based on the smooth female involucre, the species belongs to subgenus Riella Mont. However, cross-sections of this structure showed that R. choconensis has bistratose involucre walls, contrasting with the unistratose female involucres of all other species in the genus. The updated morphological data are integrated into a new key to the identification of the American species of Riella.

Paleoproterozoic basement of Içana Domain, Rio Negro Province, northwestern Amazonian Craton: Geology, geochemistry and geochronology (U-Pb and Sm-Nd)

The oldest rocks of the Rio Negro Province in the Amazonian Craton, have a complex evolutionary history and little known about them. In this paper are presented field, microtextural data, amphibole and plagioclase mineral chemistry, zircon U–Pb ages, and Sm–Nd isotope composition from Içana Domain basement rocks which belong to the Rio Negro Province. The studied area of the province is located in the extreme northwestern portion of Brazil (Amazonas State). The integration of the data obtained in this study allowed to propose the tectono-metamorphic evolution of Içana Domain in the Rio Negro Province. The basement rocks comprise orthogneiss and metagranite of the Cauaburi Complex and homogeneous/heterogeneous diatexite of the Taiuaçu–Cauera diatexite. The Cauaburi Complex rocks exhibit a predominantly porphyroclastic texture and has a mafic mineralogy constituted by biotite, amphibole, sphene, epidote, and allanite. On the other hand, Taiuaçu–Cauera diatexite varies from inequigranular to porphyroclastic, being constituted by biotite, muscovite, allanite, and epidote. Basement rocks of the Içana Domain record three tectonic–metamorphic events, which were associated to regional events. The M1/D1 event was marked by the syn-tectonic emplacement of the Cauaburi Complex protolith rocks (1813 ± 19 Ma), and also by crystallization (1821 ± 14 Ma) and migmatization (1788 ± 11 Ma) of the Taiuaçu-Cauera diatexites in an orogenic event. The M2/D2 event reached high temperatures, similar to the M1/D1 event and was related to emplacement of S–type granites in the Içana Domain basement during the Içana Orogeny (ca. 1520 Ma). Furthermore, the lower temperature of the M3/D3 event was related to intracontinental reworking of the K'Mudku event (ca. 1200 Ma). The Cauaburi Complex basement rocks shows epsilon Nd(t) values range from +1.53 to +0.13, which allow the identification of a crustal contribution to the magma source (likely Orosirian sialic crust). Geochemistry data indicate that these rocks have been generated from partial melting of amphibolitic rocks, and also with an important crustal component related to magmatic arc settings. All igneous (1967 ± 25 Ma) and metamorphic (1911 ± 15 Ma) zircons grains within the Cauaburi Complex basement rocks are compatible with those found in Tapajós-Parima/Ventuari–Tapajós Province, reinforcing the crustal contribution hypothesis. Geochemistry and mineralogical data indicate that Taiuaçu-Cauera diatexite was likely formed by the partial melting of the metagraywacke. Two age populations (1993 ± 33 and 1842 ± 9 Ma) from detrital zircon of the homogeneous diatexite, suggest that the sediments were derived from different rocks of the Tapajós-Parima/Ventuari–Tapajós Province. The age of the Taiuaçu-Cauera diatexite is probably between 1842 ± 9 Ma (youngest detrital zircon) and 1788 ± 11 Ma (anatectic zircon). The youngest detrital zircon (1842 ± 9 Ma) and anatectic zircons (1788 ± 11 Ma), indicates that the protolith of Taiuaçu-Cauera diatexite is not a part of the Tunuí basin (Tunuí Group).

Macrófitas acuáticas vasculares del sistema de drenaje del Alto Valle de Río Negro, Patagonia (Argentina)

El presente trabajo tuvo como objetivo identificar la composición florística del sistema de drenaje en el Alto Valle de Río Negro y comprender aspectos taxonómicos y biológicos. El listado florístico se obtuvo de 150 censos de vegetación (Braun-Blanquet, 1979) cuyas especies se registraron con valores de cobertura. Las macrófitas acuáticas vasculares se clasificaron según Sculthorpe (1967) y Schmidt-Mumm (1998). Los desagües fueron catalogados en rurales y urbanos según su ubicación y el origen de sus efluentes. Se evaluaron las diferencias florísticas de cada ambiente por medio de la diversidad ? -calculada través de la riqueza (S)-, índice de Shannon (H), índice de equidad de Pielou (J), valor de importancia por especie y diversidad ? a través del índice de similitud de Sørensen. El catálogo florístico exhibe 45 especies distribuidas en 32 géneros correspondientes a 23 familias, de las cuales las más representativas son Poaceae, Cyperaceae y Typhaceae. Se amplía el área de distribución de ocho especies para la provincia de Río Negro. Predominan las plantas de ciclo perenne, hábito herbáceo, tipo emergente y biotipo helophyta (82%). El mayor valor de importancia en los ambientes urbanos corresponde a Stuckenia pectinata, mientras que en los rurales a Nasturtium officinale y Azolla filiculoides. Esta investigación presenta información de base para estudios posteriores sobre el potencial bioindicador y fitorremediador de las macrófitas acuáticas vasculares del sistema de drenaje.

A new teiid lizard of the genus Callopistes Gravenhorst, 1838 (Squamata, Teiidae), from the Lower Miocene of Argentina

Although squamates are commonly found in Cenozoic South American deposits, most findings correspond to fragmentary cranial materials or isolated vertebrae. Among the known South American vertebrate fossil localities, the lower section of the Chichinales Formation (Early Miocene, Colhuehuapian South American Land Mammal Age [SALMA]), in Paso Córdoba Protected Natural Area, Río Negro Province, Argentina, recently yielded an almost complete skull of a previously unknown teiid lizard. Here, we provide a detailed description of this new fossil, based on stereoscopic and high-resolution X-ray computed tomography (CT scan) analyses. Our phylogenetic analysis recovered the new fossil within the monophyletic genus Callopistes, as the sister group of the fossil C. bicuspidatus from upper Miocene–lower Pliocene sediments (Montehermosan SALMA) of the Monte Hermoso Formation. The new species antedates the oldest previously known fossil record of the genus by at least 14 Ma, providing a minimum age of origin for the genus of approximately 20.1 Ma (based on recent revisions of the Cenozoic fossil record of SALMA). The current distribution of the two known extant species of Callopistes and the locality from which the new taxon was recovered indicate that this genus had a much broader distribution in the past that included cis-Andean areas of Patagonia during the Miocene. Our phylogenetic results further suggest that Tupinambis uruguaianensis should be allocated to the genus Dracaena.http://zoobank.org/urn:lsid:zoobank.org:pub:452C7D2A-6819-4488-9C28-1020EBD71F91SUPPLEMENTAL DATA—Supplemental materials are available for this article for free at www.tandfonline.com/UJVPCitation for this article: Quadros, A. B., P. Chafrat, and H. Zaher. 2018. A new teiid lizard of the genus Callopistes Gravenhorst, 1838 (Squamata, Teiidae), from the Lower Miocene of Argentina. Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2018.1484754.

Historical record of Holochilus vulpinus (Rodentia, Sigmodontinae) from northern Patagonia, Argentina

Abstract Marsh rats of the species Holochilus vulpinus inhabit mesic and humid environments. For this reason, it is frequently used in paleoenviromental studies to infer past humid conditions. Holocene archeological record indicates that H. vulpinus had a wider geographical distribution than today. Its regional extinction in north Patagonia at the XIX century was attributed to the dry and cold Little Ice Age (LIA). Here we present the finding of a specimen of H. vulpinus from northeastern Patagonia (Valcheta stream, Río Negro province, Argentina), just at the end of LIA. Implications of this novel historical record are discussed.

Zr-Ti-Fe placers along the coast of NE Argentina: Provenance analysis and ore guide for the metallogenesis in the South Atlantic Ocean

The Zr-Ti-Fe placers along the coast of Rio Negro and Buenos Aires Provinces, Argentina, evolved within the reaches of the Malvinas Current (1st order hydrodynamic regime). Together with some regional 2nd order local currents it is of major influence on the mineral assemblage of these terrigenous linear shoreline deposits. The nearshore-marine placers came into being in a macro- to mesotidal (San Matias Gulf) and meso- to microtidal regime (Bahia Blanca Estuary).The modern-day placers under study result from a transgressive regime with only moderate detrital input by the contemporaneous river drainage systems. The proto-placers are hallmarked among the heavy minerals (HM) by changes in the redox system which affected predominantly the Fe-Ti oxides and lead to pseudobrookites and kleberite. Light minerals (LM) in the present-day placers played a different role which is mirrored by changes in the alkalinity of the intragranular fluid system. As far as the environment of deposition is concerned in these shoreline deposits, the dune belt and backshore are most prospective as to the concentration of magnetic and non-magnetic HM. The HM assemblage of the coastal placers is a mirror image of the Afro-American part of Gondwana and its break-up history during the Mesozoic and Cenozoic. The HM reflect the alternating orogenic and anorogenic geodynamic processes operative along the passive margin of both continents. While the orogenic regimes contributed to the accumulation of metallogenetically irrelevant HM (e.g. alumosilicates, spinel, garnet, amphibole) of the placers, the anorogenic geodynamic regime may be held accountable for the target elements in the placer deposits Zr, Ti and Fe. Fe-Ti oxides (rutile, ilmenite-titanohematites, titanomagnetites) and zircon form placer deposits in their own rights with zircon playing an additional minor role also as ore guide to rift-related deposits. Titanium dioxides (Nb-Ta rutile s.s.s., struverite) and Nb titanite take the most prominent role as ore guides to rare element-bearing pegmatites, alkali magmatic rocks and carbonatites. In conclusion, the HM suite encountered in the placer deposits denotes a hot-spot mineralization at a triple junction of the South Atlantic, the Antarctic and the Proto-Iapetus Oceans. The Zr-Ti-Fe placer deposits are part of the clastic halo or expressed metaphorical as remnants of this hot-spot metallogenesis encompassing anorogenic Nb-Ta deposits related to alkaline-magmatic rocks, Skaergaard-type Fe-concentration and anorthosite-hosted Fe-Ti deposits.

Características y propiedades físicas de la madera de álamos cultivados en Río Negro, Patagonia Argentina

La populicultura en Norpatagonia, principalmente en la provincia de Río Negro, comenzó con el objetivo de establecer cortinas rompevientos para proteger cultivos frutihortícolas en sus valles irrigados. En la actualidad existen 6000 km de longitud lineal de cortinas y unas 900 ha de plantaciones en macizo de álamo en dicha provincia. El destino de la madera de estos álamos es principalmente la fabricación de embalajes, pero se utiliza también en la construcción, industria del mueble, debobinado y pasta celulósica. No existe información de características y propiedades de esta valiosa materia prima, que es necesaria para optimizar su aprovechamiento y maximizar su valor en diferentes usos. En este trabajo se describen características estéticas, algunas características microscópicas y propiedades físicas de la madera de Populus nigra cv thaisiana, P. alba var bolleana y P. x canadensis ‘conti 12’, a partir de cinco ejemplares adultos de cada especie, provenientes de cortinas rompevientos de la localidad de Allen, provincia de Rio Negro, Patagonia Argentina. La baja densidad (&lt; 0.40) y las características estéticas de la madera de las tres especies determinan su calidad para debobinado, pasta celulósica y fabricación de envases y embalajes. Los valores de contracción volumétrica (11.82%, 10.32% y 12.15%, respectivamente) y del coeficiente de contracción (V: 0.36 - 0.37) indican su ubicación entre las maderas medianamente nerviosas (medianamente estables). Los índices de anisotropía altos (A &gt; 2.3) revelan su baja estabilidad dimensional, indicando la necesidad de realizar correctos secados de la misma para su uso en aberturas y revestimientos.

Marcas y atractivos en una provincia imaginada. Río Negro, Argentina, 1958-1976

This manuscript crosses political history with cultural history. It searches the political and territorial order in Rio Negro Province since its definition about touristic attractive, because that cultural marks become in political ones. This jurisdiction contains one of the most emblematic tourist center: the town of San Carlos de Bariloche and a portion of the Nahuel Huapi National Park. But this area was not taken into account as a scenic reference of the touristic attraction of the Province. The regions presented as the image of Rio Negro emerge from politics interest established by the provincial government. The article shows that the political order, and even the citizen construction that was sought to promote in the constitutive period of the province, dialogued and was in based on the specific form of recognition of attractions established since provincial planning, which didn’t take into consideration the Andean space. The internal political construction was focused on other regions. Thus, the attractions were constituted from the political interests established by the provincial government, rather than by the materiality that was promoted.

Dinámica de la regeneración de Austrocedrus chilensis y Nothofagus dombeyi en bosques en decaimiento

The Austrocedrus chilensis forests in Argentina experience a process of decline and mortality with important impacts on the structure and population dynamics. Although its study has received significant attention over time, knowledge related to the growth of the regeneration and its response to the gradual changes in the canopy over time driven by mortality is incipient. The objective of this study was to investigate, through dendrochronological methods, the population dynamics and the radial growth of the regeneration of individuals of Nothofagus dombeyi and A. chilensis in declining forests in the northwest of Rio Negro Province, Argentina. Overstory mortality and canopy changes significantly impacted the understory structure through the establishment and growth patterns of regeneration. The average radial growth, the average age and the average diameter of the individuals of A. chilensis and N. dombeyi differed significantly. There is a positive response in the average growth of both species when the basal area loss by mortality exceeds 20 %, probably due to the higher number of changes in the instantaneous rates of growth of individuals. Based on our results, we can predict a transition from the current pure and single-cohort forests of A. chilensis towards irregular forests of mixed composition.

Tail anatomy of Buitreraptor gonzalezorum (Theropoda, Unenlagiidae) and comparisons with other basal paravians

Tail anatomy of unenlagiid theropods remains poorly known. The most complete and informative taxon of this family is Buitreraptor gonzalezorum from the Upper Cretaceous of Rio Negro province, Argentina. The aim of the present contribution is to carry out an analysis of the tail anatomy of Buitreraptor based on its holotype and a newly collected specimen as well. Similarities shared by Buitreraptor, Rahonavis, Anchiornis and Archaeopteryx include: mid-caudal vertebrae with postzygapophyses longer than prezygapophyses, and mid-caudal centra with a system of lateral laminae and concavities. Preservation of paravian skeletons, as well as muscular reconstruction, indicate the presence of two different functional sections of the tail. This contribution sheds light on paravian tail evolution and provides new data on tail changes that occurred along the theropod line towards modern birds.

The family Carditidae (Bivalvia) in the early Danian of Patagonia (Argentina)

AbstractThe first systematic analysis of the Danian carditids of Patagonia is presented, which includes four genera—one new genus and the first records of three other genera in South America. They consist ofClaibornicardia paleopatagonica(Ihering, 1903), a widely distributed species occuring in the Jagüel, Roca and Salamanca formations (Neuquén, Río Negro and Chubut Provinces);RotundicardiaHeaslip, 1968, represented by the new speciesR.mariobrosorumn. sp., which is restricted to the Roca Formation (Río Negro Province);Cardites feruglioi(Petersen, 1846) (Roca and Lefipán formations, Río Negro and Chubut Provinces); and byKalelianew genus, which includesK.burmeisteri(Böhm, 1903) from the Salamanca and Roca formations (Río Negro and Chubut Provinces), which is related to the Paris Basin speciesK.multicostata(Lamarck, 1806) n. comb. andK.pectuncularis(Lamarck, 1806) n. comb. ‘Venericardia’ iheringi(Böhm, 1903), a species known only from internal molds, is described and regarded as a carditid with uncertain affinities. The presence ofClaibornicardia,Rotundicardia, andCarditesin Patagonia constitutes the most ancient record of these genera and confirms biogeographical connections previously established between the Danian Argentinian and North American/European fossil faunas.

Escuela y alumnado: (Des)encuentros en la relación con el saber

The following article presents some preliminary results of a study conducted under the research project “The constitution of the relation with knowledge in students of the last cycle of primary education and the first one of secondary level” (National University of Comahue, Department of Psychopedagogy, 2015), implemented by the Department of Psychopedagogy at the Regional Center Atlantic Area, National University of Comahue, Argentina. In continuity with studies of human sciences that address the relation with knowledge of the subjects, and following Charlot’s (2008) theoretical contributions, this study aimed to analyze the secondary processes of establishing the relation of students with knowledge, focusing on students who culminate the primary education and start secondary level in public schools in Rio Negro Province. Identifying and problematizing specifically the meanings these students give to school knowledge, and more generally, to school and their past and future trajectories in it. The research methodology was qualitative, hermeneutical and interpretative. We implemented a psycho-pedagogical accompanying workshop; it consisted in various meetings carried out during school hours, each one organized around a particular problem and linked to a production activity- sought, to recover the students’ discourse. On the basis of written, oral, graphic and dramatic productions, we researched the objects of knowledge, the activities the students mastered, and the relational forms acquired. As a result, we found that students reported different figures of learning (Charlot, 2008),giving special relevance to the ways of relating. In turn, from school, the apprehension of knowledge is emphasized but as knowledge-relational object. Regarding the know-writing, writing follows different rules to those proposed at school that we might call standard. Finally, when you refer to the places where they learn, even though they mention different spaces to school and family, these two spaces continue to be privileged sites and institutions for learning.

Pozzolanic activity of calcined halloysite-rich kaolinitic clays

The aim of this study is to determine the pozzolanic activity of clays with high content of halloysite/kaolinite, and to evaluate the influence of halloysite/kaolinite ratio and halloysite morphology in the development of pozzolanic activity of the calcined clays. For this purpose, three different natural clays from Río Negro Province, Argentine, were selected and completely characterized. After calcined at 700°C and ground to 80% of particle size <45μm, pozzolanic activity was determined using the electrical conductivity test, the Frattini test and the compressive strength index. Results show that all calcined clays are classified as high reactive pozzolana. The presence of kaolinite and spheroidal halloysite exerts great influence at early ages; while tubular halloysite has greater influence in the pozzolanic activity and the compressive strength of mortars at later ages.

The Cauaburi magmatic arc: Litho-stratigraphic review and evolution of the Imeri Domain, Rio Negro Province, Amazonian Craton

A lithostratigraphic review of the Cauaburi Complex was carried out by means of field, tectono-metamorphic and geochemical data, which were the basis for the sub-division of the Cauaburi Complex orthogneisses into the Santa Izabel do Rio Negro, Cumati and São Jorge facies. These rocks crop out between São Gabriel da Cachoeira and Santa Izabel do Rio Negro, Amazonas, Brazil. The gneisses of the Santa Izabel do Rio Negro and Cumati facies are metaluminous and of calc-alkaline affinity; in turn, the rocks of the São Jorge facies are peraluminous and of alkaline affinity. They vary from (amphibole)-biotite granodiorites/monzogranites (Cumati and Santa Izabel do Rio Negro facies) to spessartite-bearing biotite monzogranites (São Jorge facies). The Cauaburi Complex geochemical signature is compatible with that of granites generated in collisional settings (magmatic arc?) and its evolution is related to three distinct tectono-metamorphic events: D1, causing foliation S1, which developed during the Cauaburi Complex syn-tectonic emplacement in the Cauaburi Orogeny; D2/M2, causing foliation S2, which was generated under amphibolite facies conditions (717.9 °C and 5.84 kbars), and the emplacement of I- and S-type granite during the Içana Orogen, and low-temperature D3, associated with the K'Mudku Event, which caused foliation S3 and reworking via transcurrent shear zones under greenschist facies conditions.

New hadrosaurid remains from the Late Cretaceous of Río Negro Province (Argentina, Late Cretaceous)

Fil: Cruzado Caballero, Penelope. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Patagonia Norte. Instituto de Investigacion en Paleobiologia y Geologia; Argentina

The shrinkage cracks and the diameter of the log: a experimental approach toward fuel management by Patagonian hunter-gatherer (Paredón Lanfré site. Río Negro Province, Argentin)

The anthracological study of Paredon Lanfre (Patagonia, Argentina) highlights the presence of radial cracks with a marked difference between the percentage of affected coniferous charcoal (Fitzroya cupressoides and Austrocedrus chilensis) compared to the angiosperms (e.g., Nothofagus antarctica and Nothofagus dombeyi). The aim of this work was to obtain experimental comparison data from two Patagonian conifers to understand the prehistoric combustion behavior of the region. These results showed a discrepancy between the average of shrinkage cracks made with green wood fires and those with dry wood fires. The study of the caliber of charcoal recovered from Paredon Lanfre showed significant differences between the samples of F. cupressoides and A. chilensis. The calculation of correlation between size and shrinkage cracks suggests for both species that the size is not related to the number of registered shrinkage cracks in charcoal studied. Therefore, the gauge would not be a variable which could influence the presence of shrinkage cracks in the charcoal. Consequently, the difference of average shrinkage cracks between the two specimens may result from another variable that remains to be identified.

A saltasaurine titanosaur (Sauropoda: Titanosauriformes) from the Angostura Colorada Formation (upper Campanian, Cretaceous) of northwestern Patagonia, Argentina

Saltasaurine titanosaurs are characterized by their relatively small size compared to other sauropods, extreme postcranial pneumaticity, and dermal armour covering the body. This group has been reported in the Upper Cretaceous of the Lecho, Allen, and Anacleto formations of Argentina. We describe here a new saltasaurine specimen (MACN-Pv RN 233) from the Campanian of the Angostura Colorada Formation (Río Negro Province) that is represented by eight caudal vertebrae and six osteoderms. This specimen is described in detail and its phylogenetic relationships with the other three known saltasaurines, as well as its implications to the knowledge of caudal vertebra and osteoderm anatomy, are discussed. Our results place MACN-Pv RN 233 more closely related to Saltasaurus loricatus and Rocasaurus muniozi than to Neuquensaurus australis. MACN-Pv RN 233 possesses a combination of features that differ from other saltasaurines, but because of the fragmentary nature of the specimen we decided for the sake of taxonomic stability to not erect a new taxon. This specimen shows the first unambiguous evidence of chevron pneumatisation for a sauropodomorph, implying a broader osteological invasion of the diverticula from the abdominal air sac than previously thought for this group of dinosaurs. MACN-Pv RN 233 preserves two osteoderm morphotypes, one similar to those reported for Neuquensaurus australis and Saltasaurus loricatus. This new specimen expands the distribution of the group to a new geological unit and increases the dinosaur diversity known for the Angostura Colorada Formation.

New record of titanosaurian (Dinosauria: Sauropodomorpha) osteoderms from the Upper Cretaceous of North Patagonia

The idea that titanosaurs had osteoderms was proposed in the late nineteenth century by Depéret. However, this idea was given little credence by other researchers until 1980 when unequivocal evidence of armoured titanosaurs was reported. Since then, many discoveries of titanosaurian osteoderms have been made worldwide. In this work, seven osteoderms are described from the Allen Formation (upper Campanian–lower Maastrichtian), Salitral Moreno locality, Río Negro Province, Argentina. Among the described osteoderms it was possible to recognize three morphologies (keeled, ellipsoidal and cylindrical), with the first of these being most prevalent. Although the osteoderms from Salitral Moreno resemble osteoderms found in other parts of the world, no osteoderms of a similar morphotype are known from this locality, or from Lago Pellegrini or Cinco Saltos.

New anhingid (Aves, Suliformes) from the middle Miocene of Río Negro province, Patagonia, Argentina

During the Miocene in South America, the family Anhingidae constitutes one of the most conspicuous faunal elements. However, the anhingid record from Patagonia is still sparse. The aim of the present contribution is to describe a new species of Macranhinga coming from Colloncuran levels (early middle Miocene) in Río Negro province, north-central Patagonia (Argentina). The new species is represented by an incomplete proximal end of a tarsometatarsus, distal end of a tibiotarsus, and distal end of a humerus. The phylogenetic relationships of the new species within Macranhinga remains unresolved. South American Neogene anhingids share a number of features that suggest they may belong to a monophyletic clade within this family. Anhingid records from the Miocene of Patagonia indicate that the diversity of this family was far more diverse (at least 4 different species) than currently understood, and was possible comparable to that shown by Miocene beds of Mesopotamian in Argentina and Acre in Brazil.http://www.zoobang.org/urn:lsid:zoobank.org:pub:3FC228E8-4E2C-4DFD-AB91-79F32269CA98