The Anhangueridae are a clade of toothed pterodactyloid pterosaurs, known from their characteristic anteriorly expanded premaxillae and conspicuous rostral sagittal premaxillary and dentary crests. ...Most known anhanguerids come from the Lower Cretaceous Romualdo Formation within the Araripe Basin of northeast Brazil. With four currently valid genera and several specimens referred to the clade, anhanguerids are the most abundant and diverse tetrapod group in the Romualdo Formation. However, some studies suggest this diversity may be overestimated, as many taxa have been diagnosed based on subtle differences in their premaxillary crests, a structure argued to be either ontogenetically variable or sexually dimorphic. Here we describe an anterior fragment of a gracile pterosaur rostrum that possesses the single diagnostic feature of Anhanguera (fifth and sixth pairs of dental alveoli smaller than the fourth and seventh), but lacks a sagittal crest. The affinities of the new fossil among other toothed pterosaurs were tested through both cladistic and geometric morphometric approaches, which allow referral of the new specimen to Anhanguera. The absence of a crest in the new specimen of Anhanguera suggests that this structure varies in terms of ontogeny and/or sex, and that perhaps it was influenced by sexual selection.
Os peixes fósseis da Bacia do Araripe são estudados desde o século XVII, possuindo um grande número de publicações, porém, poucos trabalhos abordam a porção oeste-sudoeste da bacia, nos estados de ...Pernambuco e Piauí. O objetivo deste trabalho é apresentar a diversidade da paleoictiofauna da Formação Romualdo no estado de Pernambuco (porção sudoeste da bacia) e comparar com a diversidade conhecida no estado do Ceará (porção leste da bacia). O material de estudo compreende 564 fósseis provenientes de 40 sítios fossilíferos dos municípios de Araripina, Exu, Trindade, Ipubi e Ouricuri, depositados no acervo da Coleção Científica Paleontológica do Departamento de Geologia da Universidade Federal de Pernambuco (DGEO-CTG-UFPE), tendo sido identificados 13 táxons: Vinctifer comptoni, Rhacolepis buccalis, Tharrhias araripis, Notelops brama, Cladocyclus gardneri, Calamopleurus cylindricus, Brannerion sp., Santanichthys diasii, Neoproscinetes penalvai, Axelrodichthys araripensis, Araripelepidotes temnurus, Paraeolops cearensis, Iansan beurleni. Foi aplicado o Índice de Shannon-Wiener visando conhecer a diversidade, o percentual das espécies e abundância no estado de Pernambuco. A espécie mais abundante foi V. comptoni (34,5%). R. buccalis (12,9%), C. gardneri (10,4%), Brannerion sp. (9%), N. brama (8,8%), T. araripis (7,9), C. cylindricus (6%) e S. diasii (4,7%), foram espécies de abundancia moderada. As espécies mais raras são N. penalvai (1,7%), A. araripensis (1,6%), A. temnurus (0,7%), P. cearensis (0,7%) e I. beurleni (0,7%). A associação fossilífera estudada apresenta maior semelhança com o município de Jardim, Ceará, devido à grande abundância de V.comptoni e a presença de R. buccalis, Brannerion sp., C. gardneri, C. cylindricus como espécies de ocorrência moderada
This work presents the osteological description and taxonomic position of new mawsoniid fossils from the Early Cretaceous Romualdo Formation (Aptian-Albian) of the Araripe Basin, in Pernmabuco, ...Brazil. The fossils were collected in the municipalities of Araripina, Exu, Ipubi and a new occurrence is registered in the municipality of Ouricuri. In total, nine specimens were identified, eight of which were assigned to the species Axelrodichthys araripensis and one to the genus Mawsonia, (Mawsonia sp.). Although the accurate analysis of these fossils determines the presence of Axelrodichthys araripensis and Mawsonia sp., the first is more abundant in the region. The fossils studied include skull, postcranial, elements dissociated from the skull, an entire specimen, some being three-dimensionally articulated as well as meristical information on the number of fin rays. Remains of the ossified lung are preserved, showing morphological similarities to the Axelrodichthys araripensis. The morphological analysis of the lung covered by bony plaques, as well as the greater predominance of A. araripensis and an associated fauna composed of vertebrates, invertebrates and typically marine microfossils, is interpreted here as a eurialine character for this species. These new records help to understand the Mawsoniid Family during the Lower Cretaceous, in the Sedimentary Basin of Araripe.
The Romualdo Formation, Aptian-Albian of the Araripe Basin, is known for the extraordinary preservation of its paleoichthyofauna. The majority of the studies performed on the basin are descriptive, ...so this study aims to analyze morphological adaptations in the paleoichthyofauna of the Romualdo Formation, seeking to understand how they influenced the life habits of fishes. To conduct the paleoecological study, 117 specimens were selected among 13 different taxa and used for the investigation of types of dentition, mouth orientation, and body morphology. A cluster analysis was carried out using morphometric data of body morphology, resulting in three groups based on the similarity index among the species. The morphology of most of the paleoichthyofauna, like Rhacolepis buccalis and Vinctifer comptoni, was adapted to swimming in high-energy environments and continuous swimming. Others, such as Araripelepidotes temnurus, presented a morphology adapted to surviving in low-energy environments, and few, like Brannerion sp. and Neoproscinetes penalvai, could perform maneuverability moves due to a deep, laterally flattened body and well-developed fins. The mouth orientation, as well as the body morphology, was of great importance to the inferences about the living zone and feeding habits of the fishes, suggesting that most inhabited the middle of the water column and were generalists regarding their feeding zone. Moreover, the types of dentition or lack thereof helped to infer food diversity and a possible food web. Therefore, the ecomorphological attributes showed some degree of morphological variations in the paleoichthyofauna, reflecting different swimming habits in environments of varied energy. The study also revealed a range of explored food resources, and the association among the fishes allowed the proposition of a rather complex food web.
•New analysis of morphological characteristics of the paleoichthyofauna of the Romualdo formation, state of Pernambuco.•Cluster analysis applied in paleoecological studies.•New interpretations about the position of the fish in the water column.•New contributions about the ecological interactions in the paleoichthyofauna of the Romualdo Formation, state of Pernambuco.
Abstract The objectives of this study were the biostratigraphic and paleobiogeographic interpretations of the calcareous nannofossil records of the Romualdo Formation (Aptian-Albian) in the ...south-central portion of the Araripe Basin. The methods used to process the samples were decanting, smear slide, centrifugation, and ultra-thin section confection. The taxonomic and biostratigraphic interpretations were carried out through qualitative and quantitative investigations. A total of 11 genera and 17 species of calcareous nannofossils, namely, Biscutum constans, Biscutum sp., Braarudosphaera africana, Braarudosphaera sp., Calculites sp., Discorhabdus ignotus, Hayesites albiensis, Hayesites sp., Nannoconus bucheri, Nannoconus sp., Retecapsa surirella, Rhagodiscus sp., Thoracosphaera sp., Watznaueria barnesiae, Watznaueria sp., Zeughrabdotus erectus, and Zeughrabdotus noeliae were identified. The integrated analysis of three outcrops suggests two distinct marine phases: the first in the Aptian, recognized in two outcrops, and during the Albian age. The genera Hayesites and Nannoconus suggest a strong Tethyan affinity. Differently, other calcareous nannofossils such as Watznaueria, Thoracosphaera, and Braarudosphaera recorded here are considered more resistant, cosmopolitan, and/or opportunistic species. Biscutum and Zeughrabdotus are sensitive calcareous nannofossils because they are more susceptible to dissolution and cannot be surely used to define this paleobiogeography and biostratigraphic range.
Aqui são apresentados antigos e novos sítios fossilíferos da Formação Romualdo, Albiano da Bacia do Araripe, no município de Exu, Pernambuco, Nordeste do Brasil, com o levantamento da sua diversidade ...fossilífera, com ênfase em paleovertebrados. Foram estudadas sete localidades da porção sudoeste da Bacia Sedimentar do Araripe, sendo identificados 16 táxons de paleovertebrados, incluindo peixes: Vinctifer comptoni, Rhacolepis buccalis, Calamopleurus cylindricus, Cladocyclus gardneri, Neoproscinetes penalvai, Paraelops cearenses, Tharrhias araripis, Notelops brama, Araripelepdotes temnurus, Brannerion sp. e Beurlenichthys ouricuriensis; pterossauros Anhangueridae e quelônios (Araripemys barretoi). A Paleofauna de vertebrados da Formação Romualdo vem sendo estudada desde 1800, é reconhecida internacionalmente como Fossillagerstätte. Porém, a região pernambucana da bacia carece de estudos sistemáticos, quando comparada com a região cearense, daí vem à necessidade de registrar as ocorrências de sítios e diversidade fossilífera, contribuindo com o conhecimento da paleontologia de vertebrados na porção sudoeste da Bacia do Araripe e ampliando os acervos paleontológicos do estado de Pernambuco.
Pterosaurs are the second most abundant fossil vertebrates in the Araripe Basin, Northeastern Brazil. As a matter of fact, this sedimentary unit has produced some of the best-preserved pterosaur ...fossils worldwide. In spite of that, most Araripe pterosaur fossils lack collection data, including precise geographic coordinates and fine-scale stratigraphic procedence. Here we describe the first pterosaur fossils from the Sobradinho site (Ceará state, Northeast Brazil). The new specimens have full collection data, being composed by exceptionally-preserved, uncompressed bones. Preserved materials include one humerus, two scapulae, two coracoids, one vertebra, one rib, and a fragment of the pelvic girdle with diagnostic features of the Pteranodontoidea. Aside from the morphological description of the new specimen, we also discuss its ontogeny, associated fauna, and the importance of geographic and stratigraphically controlled pterosaur collections, especially within the context of the Araripe Basin.
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•Morphological description of new pterosaurs from the Romualdo Formation.•Specimens with geographic and stratigraphic procedence.•First pterosaurs described for the Sobradinho site.
A influência marinha no Aptiano-Albiano da bacia sedimentar do Araripe, sempre foi sugerida a partir de fósseis de vários grupos taxonômicos como os equinoides e diversos moluscos gastrópodos e ...biválvios. Apesar da Formação Romualdo apresentar assembleias com fósseis desses invertebrados, relevantes para a indicação dessa influência marinha durante o Aptiano-Albiano, passaram muitos anos sem receber estudos apropriados. Somente após os recentes trabalhos feitos tanto com os equinoides como os moluscos ali representados possibilitou a análise paleoecológica dessas assembleias. Esses estudos possibilitarão configurar uma possível rota dessa incursão marinha ocorrida no início da formação do Oceano Atlântico. Nesse trabalho foram analisados fósseis de invertebrados de vinte sítios da Formação Romualdo, distribuídos ao longo da bacia do Araripe em Pernambuco, Ceará e no Piauí. A partir deste estudo foram feitas inferências paleoecológicas, bem como a distribuição paleogeográfica da fauna mostrando prováveis ambientes de sedimentação marinho, lagunar e estuarino, mostrando as possíveis entradas do mar na bacia. Foram constatadas espécies em comum com o Albiano da bacia de Sergipe e com a Formação Codó, no Maranhão. Essa associação de invertebrados marinhos é composta predominantemente pelos equinodermos: Pygurus (Echinopygus) tinocoi e Bothryopneustes araripensis, pelos gastrópodos: Tylostoma ranchariensis, Cerithium sergipensis, Paraglauconia (Diglauconia) araripensis e pelos biválvios: Aguileria dissita e Brachidontes araripensis. Já na associação lagunar predominam gastrópodos Paraglauconia (Diglauconia) araripensis, Gymnentome (Gymnentome) romualdoi, Gymnentome (Craginia) beurleni, "Pseudomesalia" ("Pseudomesalia") santanensis, "Pseudomesalia" ("Pseudomesalia") "mennessieri", Cerithium sergipensis e Tylostoma ranchariensis e ausência de equinoides. Na estuarina predominam os biválvios Brachidontes araripensis e Corbula sp.
The present study is based on a paleoecological and paleoclimatic analysis of the palynological associations found in the section of the Serrolândia Mine in Ouricuri, Pernambuco, which contributes to ...the reconstruction of the paleoenvironment of the Lower Cretaceous Romualdo Formation of the Araripe Basin, in northeastern Brazil. A total of 19 samples were collected from this section, which has a total height of 17 m. Only seven of these samples contained palynomorphs, which were analyzed by counting 200 palynomorphs per sample, permitting the identification of a total of 64 taxa, most of which were continental in origin. These continental palynomorph taxa included 34 pollen grains of gymnosperms and four of angiosperms, as well as the 14 spores of ferns and lycophytes, two freshwater microalgae, and fungal spores. The marine palynomorphs were represented by eight dinoflagellate cysts taxa and foraminiferal linings. The most abundant taxa overall were Classopollis spp., Afropollis jardinus, Cycadopites spp., and Gnetaceaepollenites jansonii, whose presence indicates a warm (semiarid to arid) paleoclimate. A distribution and cluster analysis identified two groups, G1, representing the lower layers (3.5–4.2 m), and G2, at a higher level (4.4–6.0 m). The palynomorphs of G1 were 92% continental and 8% marine, being represented by the dinocysts Batiacasphaera sp. A, Cometodinium ? sp., and Odontochitina ? sp. This group represents a proximal marine paleoenvironment with a strong terrestrial influence, whereas in G2, there is a decrease in the influence of continental palynomorphs (79%) and a significant increase in the contribution of marine palynomorphs (21%), including foraminiferal linings and the dinocysts of Subtilisphaera sp., Spiniferites sp., Odontochitina ? sp., and Atopodinium sp., etc. These characteristics are consistent with the conclusion that G2 represents a distal marine paleoenvironment. These findings provide important insights into the paleoenvironment of the Romualdo Formation in the Araripe Basin of northeastern Brazil during the Early Cretaceous.
•Based on the continental palynomorphs, the local environment was likely composed mainly of shrubby to arboreal xerophytic plants, typical of tropical lowland forests.•The constitution of the palynomorphs at the Serrolândia Mine implies the occurrence of progressive fluctuations in the distance from the shoreline and the depth of the water over the course of the deposition of the Romualdo Formation.•The sedimentary basins of the Aptian-Albian interval of northeastern Brazil present palynological associations, which reflect the presence of a warm (semi-arid to arid) paleoclimate.
The Cassiopidae family belongs to a group of gastropods of the Tethyan Realm, whose origin and dispersion are related a transgression of the Tethys Sea during the Early Cretaceous. The Romualdo ...Formation in the Araripe Basin, located in Northeast Brazil, presents fossil assemblages with echinoids, bivalves and cassiopid gastropods, indicating a marine sedimentation at the top of the formation. This research reveals three new species of this fauna: Gymnentome (Craginia) beurleni sp. nov., ‘Pseudomesalia’ (‘Pseudomesalia’) mennessieri sp. nov and ‘Pseudomesalia’ (‘Pseudomesalia’) santanensis sp. nov. We also review two other species: Craginia araripensisBeurlen, 1964 and Gymnentome romualdoiBeurlen, 1964, which we reclassify taxonomically as Paraglauconia (Diglauconia) araripensis and Gymnentome (Gymnentome) romualdoi, respectively; Paraglauconia (Diglauconia) lyrica Maury, 1936 and Gymnentome (Gymnentome) carregozica Maury, 1936 were the first recorded species in the Araripe Basin. The occurrence of these cassiopid gastropod fauna in other basins, such as Sergipe, Potiguar and Parnaíba, indicate the influence of waters coming from the north through the Tethys Sea in the Aptian–Albian and in the marginal continental basins of the Brazilian Northeast.
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•Cassiopidae Family gastropods are typical Tethyan Domain fauna.•Marine invertebrates at the top of the Santana Formation indicate a marine transgression.•Cassiopids in the Araripe Basin indicate the adaptive bioevent.
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