Publications by authors named "Antonio A F Saraiva"

Ephedroid macrofossils have been widely documented in Cretaceous deposits, including numerous from the Lower Cretaceous Yixian Formation of NE China. However, few ephedroid macrofossils have been reported from South America. Herein, we describe a new plant of the family Ephedraceae, gen.

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The Chaoyangopteridae is a clade of azhdarchoid pterosaurs that stands out in China, particularly in the Jehol Biota, as a Cretaceous group of medium-sized and high-crested pterosaurs. Herein, we describe a new species, Meilifeilong youhao gen. et sp.

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Direct evidence of paleo-parasitism in crustaceans is very scarce. Epicaridean isopods are obligatory parasites of crustaceans, including decapods such as crabs, shrimps, and lobsters. Their interaction with hosts is known from fossils as far back as the Jurassic through deformations of the branchial cuticle on the hosts.

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In this study we provide a comprehensive investigation of the microanatomical and microstructural aspects of the carapace and limb bones of the Early Cretaceous side-necked turtle, Araripemys barretoi, from the Araripe Basin, Brazil. Inter-elemental histovariability reveals different secondary remodelling of the skeletal elements within the same individual. The vascularisation is scarce and mainly longitudinal, also it ceases towards the bone surface, forming an avascular parallel-fibred bone with closely spaced LAGs.

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Mass mortality events are unusual in the Crato Formation. Although mayflies' accumulations have been previously reported from that unit, they lacked crucial stratigraphic data. Here we provide the first taphonomic analysis of a mayfly mass mortality event, from a layer 285 cm from the top of the Formation, with 40 larvae, and an overview of the general biological community structure of a three meters deep excavated profile.

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The Crato Formation (Araripe Basin) preserves one of the most diverse entomofaunas of the Cretaceous. Among the groups of insects, mayflies stand out in abundance, but among them oligoneuriids are especially rare. A newly discovered adult oligoneuriid from this unit is here described as Incogemina nubila gen.

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Pelomedusoides had a recognised diverse Early Cretaceous fauna of turtles in Northeast Brazil. Within them, the bothremydid Cearachelys placidoi has a relatively abundant record. This diversity contrasts with the scarcity of osteohistological studies in this group.

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The Romualdo Formation (Araripe Basin) is worldwide known for the large number of well-preserved fossils but the dinosaur record is rather scarce. Here we describe a new coelurosaur, which is the first tetrapod recovered from the basal layers of this stratigraphic unit that consist of dark shales. Aratasaurus museunacionali gen.

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The Araripe Basin is the largest inland basin in northeastern Brazil is known for its preservation excellent, number of specimens and variety of fossil species. The Araripe Basin stands out for its fossiliferous content of well known fossil groups, from vertebrates to invertebrates, especially decapod crustaceans. Thus, a morphological re-description of two shrimp species, Paleomattea deliciosa and Araripenaeus timidus, was carried out through taxonomic and morphoanatomical analysis.

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Oxygen isotope compositions of bone phosphate (δO) were measured in broiler chickens reared in 21 farms worldwide characterized by contrasted latitudes and local climates. These sedentary birds were raised during an approximately 3 to 4-month period, and local precipitation was the ultimate source of their drinking water. This sampling strategy allowed the relationship to be determined between the bone phosphate δO values (from 9.

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Pseudofrenelopsis and Brachyphyllum are two conifers that were part of the Lower Cretaceous (Aptian) taphoflora of the Crato Formation, Araripe Basin, northeastern Brazil. The former genus includes, so far, P. capillata and indeterminate species, whilst the latter is mainly represented by B.

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The Romualdo Member of the Santana Formation, a lithostatigraphic unit attributed to a marine intrusion, is famous for its preserved fossils in calcareous concretions, which stand out for their diversity and excellent preservation levels. This paper aims to record the first occurrence of the Class Insecta in the Romualdo Member of the Santana Formation of the Araripe Basin, as well as to describe and discuss the paleo-ecological implications of such finding. The first occurrence of the order Orthoptera (family Gryllidae) is presented for this unit.

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Susisuchus anatoceps is a neosuchian crocodylomorph lying outside the clade Eusuchia, and associated with the transition between basal and advanced neosuchians and the rise of early eusuchians. The specimen MPSC R1136 comprises a partially articulated postcranial skeleton and is only the third fossil assigned to this relevant taxon. Thin sections of a right rib and right ulna of this specimen have been cut for histological studies and provide the first paleohistological information of an advanced non-eusuchian neosuchian from South America.

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We used here a scanning electron microscopy approach that detected backscattered electrons (BSEs) and X-rays (from ionization processes) along a large-field (LF) scan, applied on a Cretaceous fossil of a shrimp (area ∼280 mm(2)) from the Araripe Sedimentary Basin. High-definition LF images from BSEs and X-rays were essentially generated by assembling thousands of magnified images that covered the whole area of the fossil, thus unveiling morphological and compositional aspects at length scales from micrometers to centimeters. Morphological features of the shrimp such as pleopods, pereopods, and antennae located at near-surface layers (undetected by photography techniques) were unveiled in detail by LF BSE images and in calcium and phosphorus elemental maps (mineralized as hydroxyapatite).

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The aim of this work was to evaluate the interactions between gentamicin and the ethanol extract of the fern Lygodium venustum SW (EELV). The ethanol extract of L. venustum was obtained, the phytocompounds were identified and the EELV was assayed by the checkerboard method with gentamicin against two bacterial strains multiresistant to antibiotics.

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The Crato Formation paleoflora is one of the few equatorial floras of the Early Cretaceous. It is diverse, with many angiosperms, especially representatives of the clades magnoliids, monocotyledons and eudicots, which confirms the assumption that angiosperm diversity during the last part of the Early Cretaceous was reasonably high. The morphology of a new fossil monocot is studied and compared to all other Smilacaceae genus, especially in the venation.

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Aims: In this work, the ethyl acetate and hexane fractions of Pityrogramma calomelanos (L.) were evaluated to antibacterial and antifungal activity against strains of Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Candida albicans, Candida krusei and Candida tropicalis.

Methods: The study was performed aiming to assess the antimicrobial effect with the method of dilution in HIA.

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The search for new therapeutic agents has been a constant for the treatment of diseases such as leishmaniasis and Chagas disease. Most drugs used have side effects, justifying the need to evaluate the cytotoxicity of the tested products for candidates to new drugs. In this study, the bioactivity of Lygodium venustum, a cosmopolitan fern of Lygodiaceae, was assessed about their leishmanicidal and trypanocidal potential.

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Leishmaniasis is caused by parasites of the genus Leishmania. Recent reports about leishmaniasis show a few number of drugs available, indicating the necessity of new drugs. In this study, the ethanol extract and fractions of Pityrogramma calomelanos (L.

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The preservation of delicate structures such as feathers is very rare in the paleontological record, due to the fragility of their components. Fossil feathers have been reported from approximately 50 deposits around the world, from the Late Jurassic to the Pleistocene. In Brazil initial findings consisted of a primary feather of a large bird found in the Tremembé Formation.

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