191 research outputs found

    First record of non-mammalian cynodonts (Therapsida) in the Sanga do Cabral Formation (Early Triassic) of southern Brazil

    Get PDF
    New material from the Sanga do Cabral Formation in southern Brazil is described, including one distal and three proximal portions of femora, and a distal portion of a humerus. Comparative studies indicate affinities of the proximal femora and the distal humerus with non-mammalian cynodonts, whereas the distal femur cannot be attributed with certainty to this group. These postcranial elements are the first record of non-mammalian cynodonts for the Sang a do Cabral Formation and demonstrate the presence of small- to medium-sized representatives of this group in the Early Triassic fauna of Brazil.Palaeo-Anthropology Scientific Trust; French Embassy in South Africa; Co-operation and Cultural Service

    Novo registro de floresta petrificada em Altos, Piauí: relevância e estratégias para geoconservação

    Get PDF
    Here were present a new record of fossil plants from the early Permian Pedra de Fogo Formation of the Parnaíba Basin, northeastern Brazil. This fossiliferous area, here named São Benedito Paleobotanical Site in municipality of Altos, Piauí state, and it is characterized by a great number of large gymnosperm trunks, measuring up to 1,80 m in diameter, some of them being possibly preserved in life position. More than 70 fossil tree logs were cataloged, probably constituting the largest concentration of permineralized trunks recorded in the state, surpassing the well-known Poti River Fossil Forest, in Teresina. Also, some proposals for its preservation are presented, taking into consideration that the site currently has no legal bases for its protection. This new record of fossil plants evidences the great potential for palaeobotanical studies existing in the basin.Apresenta-se aqui uma nova ocorrência de plantas fósseis na Formação Pedra de Fogo, Permiano inicial da Bacia Sedimentar do Parnaíba, NE do Brasil. A ocorrência, aqui denominada Sítio Paleobotânico São Benedito, situa-se no Município de Altos, Estado do Piauí, e caracteriza-se por apresentar uma significativa quantidade de troncos gimnospérmicos de grande porte, medindo até 1,80 m de diâmetro, sendo que alguns se encontram possivelmente em posição de vida. Foram catalogados mais de 70 troncos fósseis, configurando-se, provavelmente, na maior concentração de troncos permineralizados registrada para o estado, superando a “Floresta Fóssil do Rio Poti”, em Teresina. Por último, são apresentadas propostas de geoconservação para o sítio, tendo em vista que tal ocorrência se encontra atualmente sem bases legais para sua proteção. Este novo registro demonstra o grande potencial que existe para o desenvolvimento de estudos paleobotânicos nessa bacia

    Deep-scaled fish (Osteichthyes: Actinopterygii) from the lower Permian (Cisuralian) lacustrine deposits of the Parnaíba Basin, NE Brazil

    Get PDF
    The richly fossiliferous deposits of the Brazilian Pedra de Fogo Formation originated in an extensive aquatic system in tropical Pangaea, and grade from marginal lacustrine into marine deposits at the depocenter in the western part of the Parnaíba Basin. In addition to the well-known tetrapod and macrofloral records from these deposits, the Pedra de Fogo Formation yields extensive fish fossils indicating a diverse and abundant ichthyofauna. Among the actinopterygians, deep-bodied morphotypes are represented by whole fish as well as disarticulated dermal scales found at various localities in the states of Maranhão and Piauí. The gross morphology, ornamentation, and histology of some of these scales is highly distinctive, indicating the presence of a novel taxon (Piratata rogersmithii gen. et sp. nov.). The external surface of a Piratata scale is covered in multiple round-to-slightly elongated tubercles. The scale lacks a ganoin cover and is made up of cellular bone and odontocomplexes of orthodentine composing the tuberculated scale surface. The scale morphology and ornamentation most closely resemble that of Cleithrolepis granulatus from the Triassic of Australia and Cleithrolepis extoni from the Triassic Stormberg Beds of South Africa, but the new taxon differs from previously described species in several diagnostic morphological features. The use of scale characters in the taxonomy of ray-finned fishes and the palaeogeographic, palaeoenvironmental, and geochronological implications of the new taxon are discussed.Fil: Richter, Martha. British Museum (Natural History); Reino UnidoFil: Cisneros, Juan C.. Universidade Federal do Piaui; BrasilFil: Kammerer, Christian. North Carolina Museum Of Natural Sciences; Estados UnidosFil: Pardo, Jason. Field Museum of National History; Estados UnidosFil: Marsicano, Claudia Alicia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; ArgentinaFil: Frobisch, Jorg. Staatliches Museum fur Naturkunde Stuttgart; AlemaniaFil: Angielczyk, Ken. Field Museum of National History; Estados Unido

    Paleozoic Crown Lungfishes from Gondwana foreshadow the Early Triassic Recovery Fauna

    Get PDF
    Modern lungfishes are renowned for tolerance of extreme environmental variation, which is thought to contribute to their abundance during the recovery from the Permo-Triassic Mass Extinction (PTME). However, the Paleozoic origins of this clade and its biogeographic context remains unclear, with a 60 Ma ghost lineage at the base of the crown lungfish diversification spanning much of the Upper Carboniferous and the entirety of the Permian. This gap is particularly perplexing given the exceptional record of archaic lungfishes within this interval, particularly within paleoequatorial Euramerica, but also within eastern Europe. One possibility is that the assembly of the crown lungfish bauplan from known Carboniferous and Permian archaic lungfish groups occurred rapidly in the recovery from the PTME. However, an alternative explanation is that the crown lungfish bauplan evolved earlier in geographic regions outside the well-sampled Carboniferous and Permian basins of Euramerica, Russia, and South Africa. The sudden appearance of a diverse crown lungfish fauna in the earliest Triassic would then represent a biogeographic release in response to climate or diversity trends associated with the PTME. New lungfish faunas from outside these basins provide an opportunity to test these hypotheses. Here we report a diverse lungfish fauna from the Early Permian Pedra de Fogo Formation (Parnaíba Basin, northeastern Brazil) comprised of abundant lungfish toothplates and rarer associated or articulated skeletal remains. This fauna lacks archaic lungfish taxa (e.g. sagenodontids, ctenodontids, and conchopomatids) characteristic of contemporary localities in equatorial Euramerica. Instead, the Parnaíba fauna preserves a diverse assemblage of derived lungfishes, including a gnathorhizid and several crown lungfishes (ceratodontiforms). The gnathorhizid is represented by abundant toothplates and several partial skulls, and shows similarities to the North American gnathorhizid genera Persephonichthys and Gnathorhiza. The ceratodontiform, which is represented by toothplates as well as several partial skulls and skeletons, shows affinities with Triassic ptychoceratodontids and arganodontids, currently considered early members of the lepidosireniform stem group. Comparison with lungfish toothplate assemblages from the Paraná Basin of southern Brazil shows that the lungfish assemblage from the Parnaíba basin is also present in the Middle Permian of Brazil, likely representing a persistent biogeographic province in western Gondwana. We hypothesize that the lungfish crown group originated early in western Gondwana, but remained biogeographically restricted until the PTME eliminated incumbent competition in better-known biogeographical provinces.Fil: Pardo, Jason. University of Calgary; CanadáFil: Kammerer, Christian. Museum Fur Naturkunde; AlemaniaFil: Marsicano, Claudia Alicia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; ArgentinaFil: Angielczyk, Kenneth D.. Field Museum of National History; Estados UnidosFil: Fröbisch, Jörg. No especifíca;Fil: Smith, Roger M. H.. University of Cape Town; SudáfricaFil: Cisneros, Juan C.. Universidade Federal do Piaui; BrasilAnnual Meeting Society Vertebrate PaleontologyEstados UnidosSociety of Vertebrate Paleontolog

    A new stream treefrog of the genus Hyloscirtus (Amphibia, Hylidae) from the Río Negro-Sopladora National Park, Ecuador

    Get PDF
    Recent surveys in the Río Negro-Sopladora National Park revealed a striking new species of Hyloscirtus. The new species is easily diagnosed from all other congeners by its large body size (64.9 mm SVL in adult female); broad dermal fringes in fingers and toes; prepollex not projected into a prepollical spine and hidden under thenar tubercle; dorsum greyish-green, with paler-hued reticulum, yellow spots and black speckles; throat, venter, flanks and hidden surfaces of limbs golden-yellow with large black blotches and spots; fingers, toes and webbing yellow with black bars and spots; iris pale pink with black periphery. It is currently known only from its type locality, in the high montane forest on the southern slopes of the Cordillera Oriental of the Andes, southeastern Ecuador. The new species might be related to the H. larinopygion species group based on its morphology

    Implementación y optimización del uso de DPS en FPGA en diseño de circuitos a medida para calcular determinantes de orden 4

    Get PDF
    En este artículo se presenta el diseño e implementación de dos circuitos digitales a medida para el cálculo de determinantes de matrices de orden 4, mediante el algoritmo del Teorema de Laplace, utilizando números enteros de 8 bits. Se analizan los resultados de la implementación de los circuitos enfocados desde dos perspectivas, la primera instanciando un módulo que calcula determinantes de orden 3, mientras que enla segunda, las multiplicaciones se realizan de manera directa en el mismo bloque, reduciendo así la cantidad de unidades DSP necesarios para obtener el resultado final.En ambos casos se comparan tanto la ocupación y los tiempos de respuesta. Por otro lado, la descripción del circuito se realizó en Lenguaje de Descripción de Hardware (HDL) en el software ISE de Xilinx.Palabra(s) Clave(s): determinante, DSP, FPGA, teorema de Laplace

    Captorhinid reptiles from the lower Permian Pedra de Fogo Formation, Piauí, Brazil: the earliest herbivorous tetrapods in Gondwana

    Get PDF
    The Pedra de Fogo Formation in the Parnaíba Basin of northeastern Brazil hosts a recently discovered lacustrine fauna and provides the only known record of the Captorhinidae in South America. Here, new captorhinid remains from this unit are described. Two partial mandibles, including one formerly ascribed to the genus Captorhinus, are here referred to Captorhinikos sp. a genus previously described from North America. The natural mould of a large mandible probably represents a new taxon within the captorhinid subclade Moradisaurinae, and a small skull roof is regarded as Captorhinidae indet. Captorhinids are generally considered to have been herbivores or omnivores. The Pedra de Fogo captorhinids likely played an important ecological role as primary consumers in the palaeoenvironment of this geological unit, which is also known for its extensive record of petrified forests. The new finds reinforce the close relationships between the continental faunas of palaeotropical western Gondwana and palaeoequatorial North America during the Cisuralian

    Project: Center for Diabetes and Metabolism [Centro de Diabetes y Metabolismo: CeDiMet], a collaborative dream comes true

    Get PDF
    Reynosa urban area has 690,000 inhabitants (384,000 adults \u3e20 years old), 35% moved from other states. The use of cell phones is in 81%, personal computer or laptop with 29%. The prevalence of overweight is 39%, obesity 36%, and T2D 13%. The expected adult population with T2D is 49,900 individuals. The are 5 clinics prepared to attend T2D, and few with specialized personnel. The CeDiMet is a collaborative clinic involving health personnel and researchers from the Universidad Mexico Americana del Norte, Universidad Autonoma de Tamaulipas, Hospital General de Mexico “Dr. Eduardo Liceaga”, University of Texas Rio Grande Valley, and the Texas Diabetes Institute in San Antonio. The funding source comes from private companies in Reynosa. The clinical structure includes physicians, nurses, nutritionists, psychologists, and a section for telemedicine for consulting specialists from USA and Mexico City. Besides clinical attendance, the CeDiMet will conduct educational activities in offices, factories, churches, and schools for prevention of obesity complications (T2D and hypertension), early detection of diabetic foot, fatty liver, and endothelial damage. “Tree of Health in the Family” is a program to encourage youth to know and understand the metabolic problems in their families to focus on prevention. Recently, we obtained a grant from COTACyT to explore the effect of COVID-19 in a cohort of 200 students and their families. The analysis of post-traumatic stress due to confinement and antibodies concentration to detect contacts and its association with metabolic problems is an example of the research we can perform
    corecore