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The largest flying reptile from Gondwana: A new specimen of Tropeognathus cf. T. mesembrinus Wellnhofer, 1987 (Pterodactyloidea, Anhangueridae) and other large pterosaurs from the Romualdo Formation, Lower Cretaceous, Brazil
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A very large pterosaur (MN 6594-V) from the Romualdo Formation (Aptian/Albian), Santana Group, Araripe Basin, is described. The specimen is referred to Tropeognathus cf. T. mesembrinus mainly due to the presence of a low and blunt frontoparietal crest, the comparatively low number of teeth and the inclined dorsal part of the occipital region. Two distinct wingspan measurements for pterosaurs are introduced: the maximized wingspan (maxws), which essentially consists of doubling the addition of all wing elements and the length of the scapula or the coracoid (the smaller of the two), and the normal wingspan (nws), which applies a reducing factor (rfc) to the maximized wingspan to account for the natural flexures of the wing. The rfc suggested for pteranodontoids is 5%. In the case of MN 6594-V, the maxws and nws are 8.70 m and 8.26 m, respectively, making it the largest pterosaur recovered from Gondwana so far. The distal end of a larger humerus (MCT 1838-R) and a partial wing (MPSC R 1395) are also described showing that large to giant flying reptiles formed a significant part of the pterosaur fauna from the Romualdo Formation. Lastly, some comments on the nomenclatural stability of the Santana deposits are presented.
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... This indicates that all the expected fusions occurred before the cessation of bone growth in this individual, which is contrary to the sequence in Tropeognathus cf. mesembrinus [48]. On the basis of the existing data, inconsistencies in ontogenetic stages based on morphological and histological criteria are present among pterosaurs. ...
... On the basis of the existing data, inconsistencies in ontogenetic stages based on morphological and histological criteria are present among pterosaurs. The limited discoveries of EFS and limited knowledge about the termination of bone growth [44,[47][48][49][50] confuse the inconsistency. Another possible interpretation is that Kellner's fusion sequence is not valid for all pterosaurs because of different tempos of skeleton development [51]. ...
The Huajiying Formation (135.4–128.7 Ma) of the northern Hebei represents the early stage of the Early Cretaceous Jehol Biota in China, yielding many kinds of vertebrates. The only known pterosaur specimen was incomplete and assigned to the Ornithocheiroidea. Here we report a more complete pterosaur specimen, assigned to the Ctenochasmatidae. A new taxon is established on two autapomorphies: a large pneumatic foramen present on the ventral surface of the proximal end of the first wing phalanx; and coracoid lacking an expansion at its contact with the scapula, as well as the following combination of characteristics: subsquare sternal plate; coracoid having an extremely concave articulation with a posterior expansion; humerus without a tubercle on the proximal margin between the deltopectoral crest and the head; humerus slightly longer than the wing metacarpal; and the first and third wing phalanges equal in length. The relative thicknesses of bone walls are investigated among pterosaurs in three ways. The overall distribution of R/t ratios shows that most non-pterodactyloids, archaeopterodactyloids, and dsungaripterids have smaller R/t ratios than other groups. Relatively thick bone walls are not unique for the Dsungaripteridae as previously thought, and the humerus and radius of dsungaripterids have thinner walls than other bones. The feature of small R/t ratios is plesiomorphic and the thin-walled humerus and radius of dsungaripterids were evolved to meet the need of the flight, not for frequent take-off and landing as previously thought.
... Among them, the Ornithocheiridae (sensu Unwin, 2003) were a successful clade of piscivorous pterosaurs with long, slender, conical teeth in the anterior parts of the jaws, and shorter, laterally compressed triangular teeth in the posterior regions of the jaws. Some may have achieved a wingspan of up to 8 m (Martill and Unwin, 2012;Kellner et al., 2013). The clade ranged from the Valanginian to the end Cenomanian, and the cause of their extinction remains poorly understood (Martill and Smith, 2024). ...
A new ornithocheirid pterosaur, Akharhynchus martilli gen. et. sp. nov. from the Ifezouane Formation, Kem Kem Group, of Morocco is herein described, based on a well-preserved anterior rostrum fragment. It is assigned to a new genus based on one autapomorphy and a unique combination of synapomorphies, including the following characters: the medial rims of the first alveoli pair contact each other, the first alveoli pair are 50% smaller than the second alveoli pair. Comparative anatomy and a phylogenetic analysis demonstrate that Akharhynchus has affinities with Tropeognathus within the Tropeognathinae.
... With ever-increasing wingspan estimates, pterosaurs with a wingspan of 4 m, i.e. larger than any extant bird (Andean condor, 3.35 m; wandering albatross, 3.65 m; Dalmatian pelican and great white pelican, 3.66; Marabou stork, 3.9 m) became small fry. Today, a pterosaur is widely regarded as gigantic only if its wingspan is over 7 m (Witton and Habib 2010, but see discussion by Kellner et al. 2013), while Smith et al. (2022) suggest 6 m. Such a wingspan (.6 or 7 m) is claimed for Arambourgiania, Coloborhynchus, Hatzegopteryx, Pteranodon, Quetzalcoatlus and Tropeognathus, as well as several unnamed specimens based on taxonomically inadequate, but nonetheless huge material (e.g. ...
Pterosaurs, the first vertebrates to evolve powered flight, dominated Mesozoic skies from the Late Triassic to the end Cretaceous, a span of around 154 million years (∼220 mya to 66 mya). They achieved their greatest diversity in the mid-Cretaceous and had become globally distributed, even occurring at high latitudes and in a wide range of habitats. The pterosaur record is dominated by occurrences in conservation Lagerstätten in just a handful of countries and a narrow range of temporal windows, most notably China, Germany and Brazil and the Middle-Upper Jurassic and mid-Cretaceous respectively.
During the Cretaceous two major pterosaur clades evolved edentulism, such that by the end of the Cretaceous, no toothed pterosaurs survived, having become extinct by the mid-Cenomanian.
A distinctive aspect of pterosaur evolution during the mid-Cretaceous was the achievement of gigantic wingspans, perhaps in excess of 10 metres, hyper-elongation of the neck vertebrae in Azhdarchidae, and the evolution of highly elaborate cranial crests. For many years, pterosaur diversity in the terminal stage of the Late Cretaceous was regarded as low, but discoveries in the last few decades have indicated pterosaur taxic diversity remained high until the end Maastrichtian, although morphological diversity may have been low. The demise of the Pterosauria at the K/Pg boundary was most likely due to the same causes as the coeval dinosaur extinction associated with the Chicxulub bolide impact and its environmental repercussions. Faunal replacement by avians is no longer considered a significant factor in pterosaur extinction.
... The external surface of this crest is rugose in some areas, particularly at the posterior region, which could suggest this structure being roofed by a horny covering or soft tissue. No branching structures as reported in some other pterosaurs 15,18 were observed. ...
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. nov., based on two specimens, one tentatively referred to this taxon. This new species represents the most complete and well-preserved chaoyangopterid recorded to date. Along with a set of characters (low premaxillary crest above the nasoantorbital fenestra extending posteriorly, posterior premaxillary process arched and curving posteriorly, a slightly convex sternal articulation surface of coracoid, and a fibular shaft close to proximal articulation strongly arched posteriorly), this species also provides new information both on the unknown palatal region of this clade, and on the rarely preserved (in place) ear portion with stapes. Moreover, M. youhao sheds light on paleoecological aspects, while also giving new information about the taxonomic diversity of this peculiar group of Jiufotang pterosaurs.
Ornithocheiroidea was a globally diverse group of pterosaurs during the Cretaceous. However, well-documented ornithocheiroids are highly derived, hampering our understanding on the morphological evolution of this
clade. Dsungaripterus weii Young, 1964 from the Lower Cretaceous Tugulu Group (Valanginian) of the Junggar Basin is
an iconic early member of Ornithocheiroidea. Dsungaripterus is known from numerous three-dimensionally preserved
specimens, ranging from isolated bones to partially articulated individuals. Here we provide a comprehensive description
of the postcranium of Dsungaripterus. We find that Dsungaripterus has many autapomorphies in the postcranial skeleton
parallelling its unique skull, including the asynchronous fusion between the sacrum and pelvis and a posterodorsal fossa of
the humerus with a paper-thin bone wall. Dsungaripterus also displays some plesiomorphic features of
Ornithoecheiroidea, for example, limb bones with relatively thick bone walls, variably reduced pneumatic features in
cervical vertebrae and appendicular skeletons, absence of spinoprezygapophyseal and spinopostzygapophyseal ridges in
middle-series cervical vertebrae, at least one metacarpal articulating with the distal syncarpal, and a distally displaced
adductor ridge on the femur. Additionally, Dsungaripterus possesses some unexpected features possibly convergent with
other members of Ornithocheiroidea. Although the postcranial skeletons of Dsungaripterus are represented by
osteologically mature specimens, notable morphological variation is present. Functional reconstructions of several aspects
of the postcranial skeleton of Dsungaripterus are elucidated, including the arrangement of the metacarpophalangeal
region during terrestrial locomotion. Niche partitioning between the two dsungaripterids from the Tugulu Group of
Wuerho, Dsungaripterus and Noripterus, is supported by their distinct dentitions, neck morphology, and limb proportions.
Pterosaurs, flying reptiles that lived during the Mesozoic era, were the first vertebrates to develop powered flight. Despite being patchy, the pterosaur fossil record extends worldwide, being quite diverse at the Araripe Basin, Brazil. The Romualdo Formation (Aptian-Albian), a Konservat Lagerstätten rich in calcareous concretions, has yielded several of these exceptionally well-preserved, three-dimensional fossils. MN 4727-V, the focus of the present study, consists exclusively of three-dimensionally preserved post-cranial axial and appendicular elements. The anatomy suggests that MN 4727-V is a pteranodontoid since it exhibits an enlarged, warped deltopectoral crest and a subtriangular distal articulation of the humerus. The phyloge-netic analysis recovered MN 4727-V as an anhanguerid by the combination of the following characters: scapula substantially shorter than the coracoid (sca/co < 0.80), and posterior expansion of the sternal articulation of the coracoid. The presence of elliptical-shaped, dorsomedially inclined depressions on the dorsal surface of the prezygapophyses of the preserved cervicals has never been reported for any other anhanguerid, although they might not be diagnostic to MN 4727-V. The tail bears unique middle caudals that exhibit ventral projections, a character previously reported only for Anhanguera piscator. The wingspan of MN 4727-V, a juvenile individual, was estimated to be about 3.9 metres.
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. Their small size and low fossilization potential, outside of those larvae that have been found in amber, makes understanding the group’s evolution challenging. Here, we report the oldest evidence of paleo-parasitism in marine shrimps and an imprint of a putative adult parasite that appears to be an epicaridean isopod. Our results suggest that the parasite–host interaction between epicaridean isopods and marine shrimps started at least 110 million years ago, and the Tethys Sea was a possible dispersal pathway for this lineage of parasites during the Jurassic and Cretaceous, as known for other marine organisms through most of the Mesozoic and Cenozoic. The oldest fossil records of bopyrid swellings associated with a large number of decapods from the Jurassic in Europe suggest that the Tethys region was a center of epicaridean distribution as a whole. Recent parasitic isopods found on dendrobranchiate shrimps are restricted to the Indo-Pacific and may represent a relict group of a lineage of parasites more widely distributed in the Mesozoic.
Caiuajara dobruskii is a tapejarine pterosaur from a unique pterosaur bonebed in southern Brazil, where
hundreds of bones referred to this species have been described. Despite its abundance, specimens were
found disarticulated and/or disassociated, hindering ontogenetic interpretations from anatomy.
Osteohistology is a proper approach to obtain information on ontogeny as well as other palaeobiological
information. Here, we analyse 28 thin sections of distinct appendicular bones, from 18 different specimens
belonging to Caiuajara dobruskii. All samples display a fibrolamellar microstructure, which suggests that
Caiuajara dobruskii had high metabolic rates throughout its life history. We propose five different histology based ontogenetic stages: Early juvenile; Late juvenile; Juvenile-to-subadult transition; Subadult; and Adult.
When compared with other pterosaur ontogenetic series, Caiuajara had a higher bone deposition ratio than
other pterosaurs such as Pterodaustro and Rhamphorhynchus, even when compared with the youngest
individuals of those taxa. The fact that this bonebed shows a large accumulation of juvenile specimens in this
bonebed, whereby adults are rare and senile are absent, suggest that C. dobruskii might have developed
similar to some behaviours present in extant birds, as a breeding point and/or creching.
The skeletal proportions and size distribution of the Late Cretaceous pterosaur Pteranodon are described. The functional morphology of flight is discussed and it is argued that the patagium attached to the femora which enabled the hindlimb to assist in flapping and control of the patagium. Movements of the wing provided yaw control so that the skull and cranial crest need not be interpreted as a forward rudder. Terrestrial locomotion is discussed, and it is argued that Pteranodon and other large pterodactyloids must have been bipedal. The functional morphology of the jaws and feeding are discussed, and it is argued that Pteranodon could swim and fed while swimming on the water rather than dipping food while in flight. The function of postcranial pneumaticity is also discussed.