30 research outputs found
Ossos de pterosauro da Formação Portezuelo (Cretáceo), Grupo Neuquén, Patagônia, Argentina
The Futalognko quarry, located 90km northwest of Neuquén city, Argentina, has yielded several fossil vertebrates. All come from the upper part of the Portezuelo Formation (Turonian-Early Coniacian) and include some pterosaur remains, the first ones from the Cretaceous strata of the Neuquén Group. The material consists of a proximal end of a large ulna (MUCPv-358), the proximal part of a wing-phalanx (MUCPv-359), and another ulna associated with a radius (MUCPv-600). All specimens are referred to the Pterodactyloidea, and possibly represent members of the Azhdarchoidea. Histological sections of the large ulna (MUCPv-358) indicate that it belonged to an animal that was still growing at time of death. Comparisons with more complete specimens indicate that MUCPv-358 represents an animal with a wingspan of six meters, making it the largest pterosaur known from Argentina.O jazigo Futalognko está situado 90km a noroeste da cidade de Neuquén, Argentina, e forneceu uma grande quantidade de vertebrados fósseis, todos da parte superior da Formação Portezuelo (Turoniano- Eoconiaciano). Dentre os exemplares recuperados encontram-se alguns exemplares de pterossauros indicando a primeira ocorrência deste grupo para as rochas cretácicas do Grupo Neuquén. O material está representado pela parte proximal de uma ulna de grandes proporções (MUCPv-358), a parte proximal de uma primeira falange alar (MUCPv-359), e uma segunda ulna associada com o rádio (MUCPv-600). Todos estes exemplares são referidos a Pterodactyloidea e possivelmente representam formas de Azhdarchoidea. Seções histológicas da ulna maior (MUCPv-358) indicam que ela representa um animal jovem que estava em fase de crescimento quando morreu. Comparações com outros exemplares mais completos sugerem que MUCPv-358 tenha pertencido a um pterossauro com uma abertura alar em torno de seis metros, fazendo dele o maior réptil voador coletado até o presente momento na Argentina
First complete pterosaur from the Afro-Arabian continent : insight into pterodactyloid diversity
Despite being known from every continent, the geological record of pterosaurs, the first group of vertebrates to develop powered flight, is very uneven, with only a few deposits accounting for the vast majority of specimens and almost half of the taxonomic diversity. Among the regions that stand out for the greatest gaps of knowledge regarding these flying reptiles, is the Afro-Arabian continent, which has yielded only a small number of very fragmentary and incomplete materials. Here we fill part of that gap and report on the most complete pterosaur recovered from this continent, more specifically from the Late Cretaceous (~95 mya) Hjoûla Lagerstätte of Lebanon. This deposit is known since the Middle Ages for the exquisitely preserved fishes and invertebrates, but not for tetrapods, which are exceedingly rare. Mimodactylus libanensis gen. et sp. nov. differs from the other Afro-Arabian pterosaur species named to date and is closely related to the Chinese species Haopterus gracilis, forming a new clade of derived toothed pterosaurs. Mimodactylidae clade nov. groups species that are related to Istiodactylidae, jointly designated as Istiodactyliformes (clade nov.). Istiodactyliforms were previously documented only in Early Cretaceous sites from Europe and Asia, with Mimodactylus libanensis the first record in Gondwana
A new toothless pterosaur (Pterodactyloidea) from Southern Brazil with insights into the paleoecology of a Cretaceous desert
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 largest flying reptile from Gondwana: a new specimen of Tropeognathus cf. T. mesembrinusWellnhofer, 1987 (Pterodactyloidea, Anhangueridae) and other large pterosaurs from the Romualdo Formation, Lower Cretaceous, Brazil
New evidence of feathers in the Crato Formation supporting a reappraisal on the presence of Aves
New evidence of feathers in the Crato Formation supporting a reappraisal on the presence of Aves
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. Other occurrences are preserved in the Crato Formation, where several symmetrical and one single asymmetrical feather was found. Based on three new specimens and reassessing further feather occurrences we cannot confirm the presence of volant Aves in this deposit. The presence of an asymmetrical feather without barbules and hooks hints at the previous existence of a flightless animal within this deposit, possibly a flightlessness bird or a non-avian theropod. Conversely, the presence of a feather from morphotype II present in Tyrannosauroidea, Compsognathidae, Therizinosauroidea and Dromeosauridae, points to a non-theropod origin. Since there are no confirmed records of birds and other feathered archosaurs in the region to date, more evidence is required to identify the animal from which these structures originated
Maaradactylus kellneri Bantim & Saraiva & Oliveira & Sayão 2014, gen. et sp. nov.
Maaradactylus kellneri gen. et sp. nov. Holotype. Holotype deposited in the Museu de Paleontologia da Universidade Regional do Cariri (MPSC R 2357), Santana do Cariri-Ceará. A nearly complete skull of toothed pterosaur (Fig. 3). A complete cast of the holotype is deposited in the Laboratório de Biodiversidade do Nordeste (CAV 0014), Centro Acadêmico de Vitória / Universidade Federal de Pernambuco, Vitória de Santo Antão-Pernambuco. Type locality and horizon: São Gonçalo site, Santana do Cariri city, Ceará state, Brazil (07 º 10 '54 "S 39 ° 43' 06" W and UTM 926,286, with 596 m of altitude). Stratigraphic unit: Romualdo Formation, Santana Group, Araripe Basin. Age: Early Cretaceous-Aptian /Albian. Etymology. The genus Maaradactylus comes from a mythical legend of the Cariri Indian tribe who lived in lakes which now correspond to the Araripe Basin (Araripe plateau). Maara was a princess who was ordered to live forever in the form of a monster attacking fishermen at night; dactylus, finger, traditionally used to denote pterosaur taxa. The specific epithet “ kellneri ”, is in honor of Dr. Alexander Wilhelm Armin Kellner, due to his efforts driving the growth of Brazilian paleontology and studies involving the systematics of pterosaurs. Diagnosis. Presence of at least 35 pairs of alveoli in the skull. Premaxillary sagittal crest beginning at the anterior part of the skull (rostrum) and extending to the 22 nd pair of alveoli, not covering the nasoantorbital fenestra nor the choanae. Moderate palatal ridge, starting on the 5 th pair of alveoli and ending on the 13 th pair, which is less developed than in Tropeognathus but more so than in Anhanguera. Palate with convex shape in the anterior portion. Choanae not extending laterally. Small and convex palatal elevation in anterior portion of the skull. The 5 th, 6 th and 7 th alveoli smaller than the 4 th and 8 th. The alveoli decreasing in size from the 9 th to the 12 th and increasing from the 13 th to 18 th, and from the 18 th to the 35 th they are arranged in triplets. Description and Comparisons. The holotype of Maaradactylus kellneri gen. et sp. nov. is preserved threedimensionally in a calcareous concretion, fragmented in five parts. Some bones are partially eroded, especially on the right side of the skull and the dorsal edge of the premaxillary crest, indicating that these portions in MPSC R 2357 were exposed for a long time before collection. The skull is elongated, having a high and long sagittal premaxillary crest ending before the anterior portion of the nasoantorbital fenestra. The anterior part of the skull expands laterally in a spoon shape, typical of anhanguerids. The rostrum is rounded and contains two alveoli, which are situated in a higher position than the subsequent alveoli. The dentition is constituted by at least 35 pairs of alveoli, which increase their spacing towards the posterior direction. The maxilla is incomplete and displaced, which may mean that this specimen could have had more teeth. The frontals in Maaradactylus kellneri are unfused. The contact between the premaxilla and maxilla in M. kellneri extends from 6 th pair of alveoli to the most anterior portion of the nasoantorbital fenestra. This suture is also present in other anhanguerid pterosaurs, such as Anhanguera santanae Wellnhofer, 1985 (AMNH 22555, BSP 1 982 190) and Anhanguera piscator Kellner and Tomida 2000 (NSM-PV 19892) (Wellnhofer 1991b; Kellner and Tomida, 2000). The anterior margin of the premaxilla is rounded, different from Coloborhyncus clavirostris Owen, 1874 and Uktenadactylus wadleighi Lee, 1994, which have an anterior margin that is flattened, forming almost a right angle with the ventral margin (Rodrigues and Kellner 2008, 2013). The sagittal premaxillary crest has a maximum height of 92 mm, and in dorsal view, the anterior border of the premaxilla extend laterally forming a triangular shape. This crest begins at the first pair of alveoli (most anterior end of the rostrum) as in Tropeognathus, another genus that has a premaxillary sagittal crest located at the anterior portion of the skull. However, in Maaradactylus kellneri it extends at least until the 22 nd pair of premaxillary alveoli, with a total length of 285mm; in Tropeognathus it is shorter, extending only to the 9 th alveoli. In other anhanguerids such as Siroccopteryx moroccensis Mader and Kellner, 2003, Uktenadactylus wadleighi and all species of the genus Anhanguera, the premaxillary crest begins more posteriorly than in Maaradactylus kellneri and Tropeognathus. Furthermore the lateral surface of the premaxillary crest possesses grooves and tridimensional structures which may have housed blood vessels. The maxilla is elongate, approximately 405mm in length, and comprises a significant portion of the ventral part of the skull. It is fully preserved though slightly compressed laterally, probably during fossilization. This has displaced and obscured some elements, causing a slight shortening whose exact proportions cannot be defined. In the ventral view, the maxilla is slightly curved upward, starting approximately at the 5 th alveoli, as is observed in Anhanguera spielbergi Veldmeijer, 2003, Anhanguera santanae and Anhanguera piscator. In ventral view the opening of the nasoantorbital fenestra and an elevation of the palate can be seen, which become more evident in the anterior portion of the premaxilla, between the 5 th and 8 th alveoli. As common for pterodactyloids, the nasoantorbital fenestra occupies a considerable part of the skull, reaching about 40% of the preserved portion. Its total length is approximately 100 mm and maximum height 109 mm. In ventral view, the fenestra is partially preserved, with its limits distorted due to the dislocation of the maxilla, jugal and quadrate. The jugal forms the lower basis of nasoantorbital fenestra, orbit and temporal opening. The contact among the jugal and quadratojugal cannot be observed. The jugal forms a straight angle at the base of the nasoantorbital fenestra, narrowing toward the maxilla, ending in a thin bone. Its overall shape is similar to that of other anhanguerids. The maxillary process of M. kellneri is long and thin as in Anhanguera piscator (Kellner and Tomida 2000). In M. kellneri only the left quadrate is preserved, but it has been displaced. The quadrate is a robust bone as in other anhanguerids. It is fused with the jugal, forming a cohesive structure with no visible suture. No articulation can be identified with the squamosal, because this bone is not preserved, as well as other bones of the posterior region of the skull, such as the basisphenoid, laterosphenoid and postorbital. The supraorbital is a thin bone blade flattened dorsoventrally, which is the smallest bone in the dorsal portion of the skull. This bone has a similar morphology among all anhanguerids, as it is triangular and overlaps the posterior part of the prefrontal. The contact between this bone and the premaxilla is not preserved in M. kellneri. Along the midline, the frontals are unfused. The medial suture between the left and right sides is well developed, forming a shallow groove that runs towards the parietal. The contact surface of the frontal with the postorbital is not preserved. There is a small crest in the posterior region of the skull, formed by the contact of the frontal with the parietal. The exact length of this crest cannot be determined in MPSC R 2357, but this structure is similar to that in the Anhanguera species, in contrast to the quite robust crest in Tropeognathus. The crest in the holotype of Anhanguera santanae is longer, whereas in Anhanguera blittersdorffi Campos and Kellner, 1985, Anhanguera araripensis Wellnhofer, 1985, Anhanguera piscator and Anhanguera spielbergi is short. Maaradactylus kellneri has at least 35 pairs of alveoli, but only five alveoli preserve teeth. In the anterior portion, the alveoli are well preserved, but towards the posterior region they are weathered, especially on the left side. Except for the first pair, which is at a higher level than the second, all the alveoli are oriented ventrally (Fig. 4a,c). This characteristic is shared by most toothed pterosaurs from the Santana Group, including all species of Anhanguera, Tropeognathus mesembrinus Wellnhofer, 1987 and Ludodactylus sibbicki Frey, Martill and Buchy, 2003 (Rodrigues and Kellner 2008). Other anhanguerids also share this condition (Campos and Kellner 1985; Kellner 2003; Rodrigues and Kellner 2008; Martill and Unwin 2012), as does " Ornithocheirus " sedgwickii (Owen, 1859) and " Ornithocheirus " cuvieri (Bowerbank, 1851), Caulkicephalus trimicrodon Steel, Martill, Unwin and Winch, 2005, Siroccopteryx moroccensis and Uktenadactylus wadleighi. The first alveolus has a reduced size (5mm), similar to the condition present in other anhanguerids. The second alveolus is larger than the first, but smaller than the third and fourth. The third and fourth alveoli are larger (12mm and 13mm, respectively). Three smaller alveoli of similar size are present after the 4 th alveoli: the 5 th, 6 th and 7 th alveoli are smaller than the 4 th and 8 th (Fig. 4b,d). From the 9 th to the 12 th positions, the alveoli decrease in size, and from the 13 th to the 18 th they increase in size again. The alveoli are arranged in triplets from the 18 th to the 35 th. These are arranged linearly and each triplet is separated by about 3 to 4 cm (an exclusive characteristic of M. kellneri). The dentition of Pterodactyloidea shows some specializations, with teeth varying in shape, number and disposition within the jaws. This variation includes taxa with hundreds of tiny elongated teeth, such as Ctenochasma (Bennett 2007) and Pterodaustro (Chiappe and Chinsamy 1996), and taxa with a reduced number of teeth, as seen in Tropeognathus (Kellner et al. 2013). Other lineages possess a very specialized and unique dentition, like Dsungaripteridae, where the anterior parts of the upper jaws are toothless (Lü et al. 2009). In this group the distance between teeth is greater in the middle portion of the dentition than in the anterior and posterior portions of the upper and lower jaws, where the space between teeth is shorter (Lü et al. 2009). Maaradactylus kellneri has the highest number of alveoli of all anhanguerids and related taxa. Regarding the genus Anhanguera, the species with the closest alveoli count to Maaradactylus kellneri is Anhanguera blittersdorffi, which has 26 pairs in the holotype (MN 4805-V) and 22 in a referred specimen (n. 40 Pz-DBAV-UERJ). Anhanguera santanae and Anhanguera piscator both have 20 pairs. Anhanguera spielbergi and Anhanguera araripensis (specimen MN 4735-V) show even fewer alveoli, with 18 pairs each. In Cearadactylus? ligabuei Dalla Vecchia, 1993 there are 22 pairs, while Cearadactylus atrox Leonardi and Borgomanero, 1985 has 16 pairs. The most limited dentition is in Tropeognathus mesembrinus Wellnhofer, 1987, which has only 14 pairs of alveoli. The palatine contacts the maxilla laterally, and subsequently limits the opening of the choanae. Posterior to this is a relatively low sagittal ridge, beginning at the 5 th alveoli and ending at the 12 th. Other anhanguerids also have this structure, such as Anhanguera blittersdorffi, whose palatal ridge extends posteriorly until the anterior border of the choanae and anteriorly to the expansion of the premaxilla, disappearing between the 4 th and 5 th alveoli. Anhanguera araripensis also has a small ridge on the palate, which starts at the 9 th alveoli and ends at the 12 th alveoli. In Anhanguera santanae the palatal ridge is most evident at the 6 th alveoli, and in Anhanguera spielbergi it is more tenuous, positioning itself between the 5 th and 10 th alveoli. In Tropeognathus mesembrinus the palatal ridge is extremely high and robust, the largest among anhanguerids.Published as part of Bantim, Renan A. M., Saraiva, Antônio A. F., Oliveira, Gustavo R. & Sayão, Juliana M., 2014, A new toothed pterosaur (Pterodactyloidea: Anhangueridae) from the Early Cretaceous Romualdo Formation, NE Brazil, pp. 201-223 in Zootaxa 3869 (3) on pages 204-207, DOI: 10.11646/zootaxa.3869.3.1, http://zenodo.org/record/494724
A new angiosperm from the Crato Formation (Araripe Basin, Brazil) and comments on the Early Cretaceous Monocotyledons
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. Cratosmilax jacksoni gen. et sp. nov. can be related to the Smilacaceae family, becoming the oldest record of the family so far. Cratosmilax jacksoni is a single mesophilic leaf with entire margins, ovate shape, with acute apex and base, four venation orders and main acrodromous veins. It is the first terrestrial monocot described for the Crato Formation, monocots were previously described for the same formation, and are considered aquatics. Cratosmilax jacksoni is the first fossil record of Smilacaceae in Brazil, and the oldest record of this family
Redescription of <i>Cearadactylus atrox</i> (Pterosauria, Pterodactyloidea) from the Early Cretaceous Romualdo Formation (Santana Group) of the Araripe Basin, Brazil
<div><p>ABSTRACT</p><p>Based on one of the first cranial pterosaur specimens unearthed from the Romualdo Formation (Araripe Basin), <i>Cearadactylus atrox</i> has caused disagreement among paleontologists regarding its relationships. Ranging from an ornithocheirid, an indeterminated pterodactyloid, to a ctenochasmatid, some authors even regarded this species as representing a distinct suprageneric clade. Further preparation of the holotype that was transferred to the collections of the Museu Nacional/UFRJ (MN 7019-V) revealed several new features allowing a redescription and reevaluation of the phylogenetic position of this species. Among the new observations, it is clear that the rostral end of this specimen had been glued to the skull, rendering previous anatomical interpretations incorrect. There is no rostral gap, and the expanded rostral end of the premaxillae is larger than the dentary, rather than smaller. <i>Cearadactylus atrox</i> is here considered a valid taxon that can be diagnosed by a dentary groove that bifurcates at the rostral end, orbit and naris in a high position relative to the nasoantorbital fenestra, and a comparatively small number of teeth (32–36 maxillary, 22–26 mandibular), decreasing in size towards the posterior end. Phylogeneticaly, it is placed as the sister group of the Anhangueridae, forming a large clade of Brazilian forms (<i>Tropeognathus</i> and <i>Anhanguera</i>), which has a European taxon (‘<i>Ornithocheirus</i>’ <i>compressirostris</i>) as its sister group.</p>
<p>SUPPLEMENTAL DATA—Supplemental materials are available for this article for free at <a href="http://www.tandfonline.com/UJVP" target="_blank">www.tandfonline.com/UJVP</a></p>
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Osteohistology and growth dynamics of the Brazilian noasaurid Vespersaurus paranaensis Langer et al., 2019 (Theropoda: Abelisauroidea)
Although the knowledge of bone histology of non-avian theropods has advanced considerably in recent decades, data about the bone tissue patterns, growth dynamics and ontogeny of some taxa such as abelisauroids are still limited. Here we describe the bone microstructure and growth dynamics of the Brazilian noasaurine Vespersaurus paranaensis using five femora and six tibiae and quantify the annual growth marks through retrocalculation of missing ones to estimate ontogenetic ages. The femoral series comprises four femoral histological classes (FHC I-IV), varying from two annuli or LAGs to seven LAGs. Femora show that sexual maturity was achieved around the seventh to tenth year of life, whereas the tibiae suggest it was earlier (around three to five years old). Tibiae represent three histological classes (THC I-III) displaying from three to nine LAGs. Two tibiae (THC III) exhibit an external fundamental system indicating that these specimens reached full skeletal size. The heterogeneous maturity observed in Vespersaurus hind limb bones could result from differential allometry scaling between femora and tibiae length with the body length. The predominant parallel-fibered bone matrix suggests that Vespersaurus grew more slowly than most theropods, including other abelisauroids, in a pattern shared with the noasaurines Masiakasaurus knopfleri from Madagascar and CPPLIP 1490 from Brazil. This deviation from the typical theropod growth pattern may be mainly correlated with small body size, but also may related to resource limitation imposed by the arid climate prevailing in southwestern Gondwana during Cretaceous. Moreover, given the ecological and phylogenetic similarities among these taxa, such features would probably be apomorphic within Noasauridae