A pterosaur bone bed with at least 47 individuals (wing spans: 0.65–2.35 m) of a new species is reported from southern Brazil from an interdunal lake deposit of a Cretaceous desert, shedding new light on several biological aspects of those flying reptiles. The material represents a new pterosaur, Caiuajara dobruskii gen. et sp. nov., that is the southermost occurrence of the edentulous clade Tapejaridae (Tapejarinae, Pterodactyloidea) recovered so far. Caiuajara dobruskii differs from all other members of this clade in several cranial features, including the presence of a ventral sagittal bony expansion projected inside the nasoantorbital fenestra, which is formed by the premaxillae; and features of the lower jaw, like a marked rounded depression in the occlusal concavity of the dentary. Ontogenetic variation of Caiuajara dobruskii is mainly reflected in the size and inclination of the premaxillary crest, changing from small and inclined (∼115°) in juveniles to large and steep (∼90°) in adults. No particular ontogenetic features are observed in postcranial elements. The available information suggests that this species was gregarious, living in colonies, and most likely precocial, being able to fly at a very young age, which might have been a general trend for at least derived pterosaurs.
Iguanians are one of the most diverse groups of extant lizards (>1,700 species) with acrodontan iguanians dominating in the Old World, and non-acrodontans in the New World. A new lizard species presented herein is the first acrodontan from South America, indicating acrodontans radiated throughout Gondwana much earlier than previously thought, and that some of the first South American lizards were more closely related to their counterparts in Africa and Asia than to the modern fauna of South America. This suggests both groups of iguanians achieved a worldwide distribution before the final breakup of Pangaea. At some point, non-acrodontans replaced acrodontans and became the only iguanians in the Americas, contrary to what happened on most of the Old World. This discovery also expands the diversity of Cretaceous lizards in South America, which with recent findings, suggests sphenodontians were not the dominant lepidosaurs in that continent as previously hypothesized.
The first pterosaur bone bed from Brazil was reported in 2014 at the outskirts of the town Cruzeiro do Oeste, Paraná State, in the Southern region of the country. here named `cemitério dos pterossauros´ site, these outcrops were referred to the Goio-Erê Formation (turonian-Campanian) of the Caiuá Group (Bauru Basin) and revealed the presence of hundreds of isolated or partially articulated elements of the tapejarine pterosaur Caiuajara and fewer amounts of a theropod dinosaur. here we present a new tapejaromorph flying reptile from this site, Keresdrakon vilsoni gen. et sp. nov., which shows a unique blunt ridge on the dorsal surface of the posterior end of the dentary. Morphological and osteohistological features indicate that all recovered individuals represent late juveniles or sub-adults. This site shows the first direct evidence of sympatry in Pterosauria. The two distinct flying reptiles coexisted with a theropod dinosaur, providing a rare glimpse of a paleobiological community from a Cretaceous desert.
The most recent Giant Gaussian Process (GGP) model, based on the last 5 Ma, has been used as a reference for directional distribution of paleomagnetic record of older rocks as Cenozoic and Proterozoic. However, for Paleozoic times, its validity has not yet been tested. Here we evaluate the validity of this recent GGP model for the Kiaman superchron. We present new paleomagnetic results from a late Pennsylvanian section of glacial rhythmites (Mafra Formation) from southern Brazil. The 5-m section sampled spans more than 800 kyr, as evaluated by cyclostratigraphic analysis. Thermal demagnetization revealed a reversed characteristic component carried by single domain magnetite. Anisotropy of anhysteretic remanent magnetization indicated a small shallowing correction of f = 0.97. The final paleomagnetic pole position is located at 51.9°S, 344.3°E (N = 111, R = 109.0, K = 55.9, A 95 = 1.8°), with a mean direction of Dec = 144.2°, Inc = 69.5°(N = 111, R = 110.2, k = 134.4, α 95 = 1.2°, Paleolat = 53.2°S). The shape of the distribution of magnetization directions (elongation E = 2:08 3:13 1:44 Þ and the dispersion of virtual geomagnetic poles (S V ¼ 10:9 11:8 9:8 Þ are incompatible with the recent model. The reduced dispersion, also found in other studies, implies a different shape in directional distributions for any GGP model describing the Kiaman interval. This result alerts us that we should abandon the use of the recent GGP model as a reference for inclination shallowing correction of Carboniferous sedimentary data.
Actinopterygians (ray-finned fishes) are the most diverse group of living fishes, but have a sparse Devonian fossil record restricted to low palaeolatitudes. Here we report a new actinopterygian from the Paraná Basin of Brazil, which occupied a circumpolar position in the Palaeozoic. Available geological evidence supports a Middle Devonian or older age for this taxon, which shares features of the mandibular symphysis with the latest Devonian
Tegeolepis
. A phylogenetic analysis resolves these two as sister taxa. This new record expands the palaeogeographic distribution of Devonian ray-fins and suggests that gaps in their fossil record might be filled by exploring poorly sampled high-latitude localities within the Malvinokaffric Realm.
An abundant and diverse fossil record, encompassing some specimens with exceptional preservation, identifies the Campáleo outcrop in the earliest Permian marine Lontras Shale of the Paraná Basin, in the northern uplands of State of Santa Catarina, Brazil as a Carboniferous-Permian fossillagerstätte. Among others, a relatively rich entomofauna was recently discovered in pyrite-rich black shales, yielding several exceptionally preserved, partly pyritized, body fossils of 'cockroachoid' (Blattodea) insects. Some of these were identified as Anthracoblattina mendesi Pinto & Sedor, which is revised here in a preliminary comparison with all Palaeozoic related species known thus far from South America. Based on these new finds, A. mendesi becomes the most complete Palaeozoic blattoid described so far from South America. Several sub-complete individuals provide additional information about the anatomy of Late Palaeozoic blattoids, in general. The new finds demonstrate that the genus Anthracoblattina is not only a common and typical component of the Euramerican Late Pennsylvanian/early Permian entomofauna, but was also present in the South American Gondwana entomofauna. It is hypothesized that Anthracoblattina immigrated from Euramerica into this part of Gondwana during a climate amelioration event during the course of the Late Paleozoic Ice Age (LPIA), as it is indicated by the transgressive marine Lontras Shale.
Esse trabalho investiga a porção média da Formação Mafra (Grupo Itararé) na região de Mafra(SC)-Rio Negro(PR). Uma sondagem com 40m testemunhados (PM-6), adjacente a uma grande pedreira com 70m de altura, fornece, em conjunto, quase 100m de seção, dominada por varvitos e diamictitos, representativa do Mafra-Médio. Recobrindo erosivamente esse intervalo, a mesma pedreira expõe 20m de arenitos sigmoidais, já caracterizando a unidade Mafra-Superior. A Formação Mafra-Médio consiste de ciclos de granocrescência ascendente (varvito a diamictito), recobertos por um complexo ciclo granodecrescente (arenito-diamictito-varvito), atribuído a eventos de deglaciação; esse evento culmina com a deposição de siltito fossilífero marinho, que, ao contrário das demais fácies, não tem clastos caídos (dropstones). As complexas relações laterais que marcam o ciclo/evento de deglaciação podem ser documentadas em uma seção estratigráfica com cinco afloramentos. A base do evento é erosiva, fornecendo calhas que acomodam localmente grandes espessuras; tal sucessão transgressiva, desenvolvida com a deglaciação, deve-se ao recuo progressivo das geleiras. O intervalo médio da Formação Mafra representa um trato de sistemas transgressivo/de nível de base alto de uma seqüência deposicional de 3ª ordem, junto com os arenitos e siltitos do Mafra-Inferior, estes constituindo o trato de sistemas de nível baixo.
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