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New observations on the osteology and taxonomic status of Preondactylus buffarinii WILD, 1984 (Reptilia, Pterosauria).
Abstract
New observations about the osteology and the systematic position of Preondactylus buffarinii Wild 1984b, are based on a reexamination of the holotype (1770MFSN). The carpus and metacarpus of this specimen are described in detail after further preparation. New measurements for the wing metacarpal, first wing phalanx and tibia are presented, allowing new postcranial bone length ratios to be calculated. Similarities of P. buffarinii to Peteinosaurus zambellii are emphasized; its condition of most primitive pterosaur is open to discussion and its diagnosis is emended.
... The Endenna site yielded three articulated wing phalanges (MCSNB 4562) and an isolated sternum (MPUM 7039). MCSNB 4562 represents a very large individual for the standards of the non-pterodactyloid pterosaurs, which was referred to Preondactylus buffarinii by Wild (1984) because of the length ratio between wing phalanges 3 and 2. Dalla Vecchia (1998) argued that the ratio (0.96, estimated; but it is 1.03 -0.89 in Padian 1980) is not reliable for taxonomic purposes because it is as close to that of the holotype of Preondactylus buffarinii (1.00) as well as those of Austriadactylus cristatus Dalla Vecchia et al. 2002 (1.02) and Dorygnathus banthensis (Theodori 1830) (1.01). Dalla Vecchia (1998) considered the specimen an indeterminate basal pterosaur. ...
... MCSNB 4562 represents a very large individual for the standards of the non-pterodactyloid pterosaurs, which was referred to Preondactylus buffarinii by Wild (1984) because of the length ratio between wing phalanges 3 and 2. Dalla Vecchia (1998) argued that the ratio (0.96, estimated; but it is 1.03 -0.89 in Padian 1980) is not reliable for taxonomic purposes because it is as close to that of the holotype of Preondactylus buffarinii (1.00) as well as those of Austriadactylus cristatus Dalla Vecchia et al. 2002 (1.02) and Dorygnathus banthensis (Theodori 1830) (1.01). Dalla Vecchia (1998) considered the specimen an indeterminate basal pterosaur. Surprisingly, Barrett et al. (2008, p. 62) referred this specimen to 'Peteinosaurus sp. ...
... Preondactylus buffarinii is diagnosed by the short and dorsally convex premaxilla body that comprises the tip of the snout and the relative length of the dentary, which is less than half the length of the complete lower jaw (Dalla Vecchia 2003). Another possible apomorphy is that metacarpal I is markedly shorter than metacarpals II and III, which are of similar length (Dalla Vecchia 1998). Preondactylus buffarinii shares with Austriadactylus cristatus one to possibly three very enlarged, triangular and serrated maxillary teeth below the ascending process of the maxilla, followed posteriorly by triangular, serrated teeth decreasing regularly in size; unlike Austriadactylus cristatus, it has premaxillary and anterior mandibular teeth that are not significantly enlarged and are recurved backwards. ...
Pterosaurs are a clade of highly specialized, volant archosauromorphs recorded from
the Upper Triassic to the uppermost Cretaceous. Problematic remains referred to the Pterosauria
are reported from the Triassic of Europe and both North and South America, but unequivocal
pterosaur specimens are only known from the Alps (Italy, Austria and Switzerland: Preondactylus
buffarinii, Austriadactylus cristatus, Peteinosaurus zambellii, Eudimorphodon ranzii, Carniadactylus
rosenfeldi, Caviramus schesaplanensis and Raeticodactylus filisurensis) and Greenland
(‘Eudimorphodon’ cromptonellus). Pterosaurs are diagnosed mostly by features associated with
the advent of powered flight. They are generally considered to be archosaurians more closely
related to dinosaurs than to crocodilians, but non-archosaurian positions have also been proposed.
There is a lack of general agreement about ingroup relationships, particularly among the basal
pterosaurs. Triassic pterosaurs differ from other non-pterodactyloid pterosaurs in features of the
dentition and caudal vertebral column. A ‘Big Bang’ model for their early history fits better
with the fossil record: the earliest unequivocal pterosaurs show a sudden and geographically
limited appearance in the fossil record, as well as a relatively high burst of diversity and considerable
morphologic disparity. Absence of pterosaur remains from deposits where they are expected to
be found suggests that they had not yet evolved in pre-Norian times.
... The primary candidates were long thought to be Preondactylus (Unwin, 2003a(Unwin, , 2003b and Austriadactylus, which together form Preondactylia (see, Andres et al., 2014), and the Anurognathidae (Kellner, 2003). The former is known from several specimens, two of which contain very little information, with the best preserved of these being of poor preservation, with bones largely left as impressions in the matrix (Dalla Vecchia, 1998). Based on the disarticulation of the skull, the holotype is also likely to be a juvenile, adding issues of ontogeny. ...
... In the analyses of Britt et al. (2018), Austriadraco dallavecchiai and Arcticodactylus cromptonellus formed a small clade -Austriadraconidae -which formed the sister-taxon to all other pterosaurs; in the analysis of Dalla Vecchia (2019) the earliest diverging clade was found to be the clade containing Preondactylus bufarinii and Austriadactylus cristatus, with the 'austriadraconids' placed in more derived positions (Fig. 3). Dalla Vecchia (2019) also found a clade within the more 'derived' members of Pterosauria comprising several taxa, including Caviramus schesaplanensis, Carniadactylus rosenfeldi and Seazzadactylus venieri,termed Caviramidae by Baron (2020) (perhaps synonymous with the 'Caviraminae' of Dalla Vecchia, 1998), and which forms the sister-taxon to Zambellisauria (Fig. 3). For a full discussion of the ingroup topology within each hypothesis, see Baron (2020). ...
Our understanding of the pterosaurs' place within the reptilian lineage has had a long and complex history. The unusual morphology of pterosaurs, which is inextricably linked to their habit of powered flight, has generated numerous proposals over the years regarding their exact origin and systematic position. Though it was concluded early on in pterosaur research history that these animals represented a group of derived flying reptiles, their exact origination remained mysterious for a long time and is still somewhat controversial. A rough consensus has now been reached that pterosaurs are derived archosaurs and are likely close relatives of the dinosaurs, united with them in the clade Ornithodira, though some still challenge this view. The anatomical evidence in support of this position close to Dinosauria is also admittedly fairly limited at present, largely owing to a lack of any clear-cut transitional ‘proto-pterosaur’ taxa (albeit that some fragmentary specimens have been suggested to represent exactly this). Differing hypotheses have also recently been put forward as to the exact interrelationships between the pterosaurs and other non-dinosaurian and dinosaurian ornithodirans. Here the previous hypotheses of where pterosaurs fit into the reptilian lineage and the anatomical evidence in support of the current hypotheses are reviewed. Results of new analyses are included that looked to test the origin and systematic position of the Pterosauria using an expanded version of a large anatomical dataset of archosaurs, within which several previously unconsidered early pterosaur taxa and a suit of new anatomical characters were considered. The analyses in this study support the close affinities between pterosaurs and dinosauriforms within Ornithodira; Pterosauria is recovered as the sister-taxon to Lagerpetidae. Such a result suggests that the clade Pterosauria belongs with Lagerpetidae as part of a broader Pterosauromorpha that then, with Dinosauriformes, falls within Ornithodira. The anatomical evidence in support of this position within Ornithodira is also discussed in detail.
... The pterosaur Preondactylus bufarinii is within the area of dinosauromorphs. This is interesting, because this taxon lacks the edentulous and tapering anterior end of the dentary (Dalla Vecchia, 1997), which is present in some early pterosaurs (Ezcurra et al., 2020). The PCo 1 segregates lagerpetids and dinosauromorphs. ...
Exquisite discoveries and new interpretations regarding an enigmatic group of cursorial avemetatarsalians led to a new phylogenetic hypothesis regarding pterosaur affinities. Previously thought to be dinosaur precursors, lagerpetids are now considered to be the closest relatives to pterosaurs. This new hypothesis sheds light on a new explorable field, especially regarding the character acquisition and evolution within the pterosaur lineage. In the present study, the morphospace occupation of distinct skeletal regions of lagerpetids within the morphological spectrum of avemetatarsalians is investigated. This approach indicates which portions of the skeleton are more similar to the anatomy of pterosaurs and which portions present different homoplastic signals. The analyses demonstrate that the craniomandibular traits of lagerpetids are pterosaur‐like, the pectoral girdle and forelimb are dinosauromorph‐like and the axial skeleton and the pelvic girdle and hindlimb are unique and highly specialized among the analyzed sample. So, despite the close phylogenetic relationships, the postcranial skeleton of lagerpetids and pterosaurs are very different. The occurrence of two distinct and highly specialized groups of pterosauromorphs coexisting with a wide ecological range of dinosauromorphs during the Triassic suggests pressure for new niches occupation.
A new and articulated specimen of a pterosaur wing including upper arm, forearm, parts of the carpus and metacarpus, and a wing phalanx from Maastrichtian phosphatic deposits of Morocco are assigned to Tethydraco cf. regalis Longrich et al., 2018.
The specimen comes from the village of Ouled Abdoun, close to the Oued Zem basin and its phosphatic mines (Morocco). The fossil is part of the collection of the Université Hassan II of Casablanca (ID Number FSAC CP 251).
In the first part, the thesis presents a synthetic introduction about the morphology, anatomy, physiology and evolution of pterosaurs in order to offer a comprehensive framework on this fascinating group of extinct flying tetrapods.
The main goal of this work is the taxonomic identification of the specimen, principally by morphological and morphometric/statistic analysis, based on the comparison with the most similar pterosaurs of the same epoch.
Aspect of the humerus morphology and dimensional ratios of the wing elements suggest that T. cf. regalis is an azhdarchid rather than pteranodontid, as originally proposed. A high abundance of azhdarchid remains in the open marine setting of the Moroccan phosphates casts doubt on suggestions that Azhdarchidae were largely terrestrial pterosaurs.
A nearly complete but poorly preserved amniote from the Middle-Upper Norian of Friuli (NE Italy), previously attributed to a new species of the protorosaur genus Langobardisaurus (L. rossii Bizzarini & Muscio, 1995), is re-described. Study reveals that the specimen does not exhibit any protorosaurian characters, instead all available evidence supports its attribution to the Lepiclosauromorpha. Some skull characters might support sphenoclontian affinities, but preservation is too poor to allow a firm assigment to this group.
The skull of the holotype of the Late Triassic diapsid reptile Megalancosaurus preonensis is described for the first time. Its study revealed affinities with archosauromorph reptiles along with striking similarities with basal pterosaurs, apart for the absence of an antorbital fenestra.
Traditionally, pterosaurs have been included within the Archosauriformes and many contemporary workers consider the Pterosauria the sister group to Lagosuchus, Scleromochlus and the Dinosauria. New analyses cast doubts on those relationships because nearly all presumed archosauriform or ornithodire "synapomorphies" are either not present within the Pterosauria or are also present within certain prolacertiform taxa. Recent examinations of the holotypes of Cosesaurus aviceps, Longisquama insignis and Sharovipteryx mirabilis suggest that many characters may be interpreted differently than previously reported. Results of several subsequent cladistic analyses suggest that these three "enigmatic" prolacertiforms, along with the newly described Langobardisaurus, are sister taxa to the Pterosauria based on a suite of newly identified synapomorphies.
A small accumulation of bones from the Norian (Upper Triassic) of the Seazza Brook Valley (Carnic Prealps, Northern Italy) was originally (1989) identified as a gastric pellet made of pterosaur skeletal elements. The specimen has been reported in literature as one of the very few cases of gastric ejecta containing pterosaur bones since then. However, the detailed analysis of the bones preserved in the pellet, their study by X-ray microCT, and the comparison with those of basal pterosaurs do not support a referral to the Pterosauria. Comparison with the osteology of a large sample of Middle-Late Triassic reptiles shows some affinity with the protorosaurians, mainly with Langobardisaurus pandolfii that was found in the same formation as the pellet. However, differences with this species suggest that the bones belong to a similar but distinct taxon. The interpretation as a gastric pellet is confirmed.
It was claimed that pterosaurs had external mandibular fenestrae, antorbital fossae and muscle scars homologous with the femoral fourth trochanter of archosauriforms, and that those characters suggested that the Pterosauria were within the clade Erythrosuchus + Archosauria. Pertinent parts of available specimens are described to confirm that one pterosaur had external mandibular fenestrae and one had antorbital fossae. However, arguments are presented that possession of external mandibular fenestrae does not support inclusion of the Pterosauria within the clade Erythrosuchus + Archosauria and that the antorbital fossae in the one pterosaur are not homologous with those of the clade Erythrosuchus + Archosauria. Arguments are also presented that the possession of a m. caudofemoralis scar by some pterosaurs does not support inclusion of the Pterosauria within the clade Erythrosuchus + Archosauria, whereas the lack of homologous antorbital fossae and a mound-like or aliform fourth trochanter supports exclusion of the Pterosauria from that clade.
Pterodactyloid pterosaurs are widely interpreted as terrestrially competent, erect-limbed quadrupeds, but the terrestrial capabilities of non-pterodactyloids are largely thought to have been poor. This is commonly justified by the absence of a non-pterodactyloid footprint record, suggestions that the expansive uropatagia common to early pterosaurs would restrict hindlimb motion in walking or running, and the presence of sprawling forelimbs in some species. Here, these arguments are re-visited and mostly found problematic. Restriction of limb mobility is not a problem faced by extant animals with extensive fight membranes, including species which routinely utilise terrestrial locomotion. The absence of non-pterodactyloid footprints is not necessarily tied to functional or biomechanical constraints. As with other fully terrestrial clades with poor ichnological records, biases in behaviour, preservation, sampling and interpretation likely contribute to the deficit of early pterosaur ichnites. Suggestions that non-pterodactyloids have slender, mechanically weak limbs are demonstrably countered by the proportionally long and robust limbs of many Triassic and Jurassic species. Novel assessments of pterosaur forelimb anatomies conflict with notions that all non-pterodactyloids were obligated to sprawling forelimb postures. Sprawling forelimbs seem appropriate for species with ventrally-restricted glenoid articulations (seemingly occurring in rhamphorhynchines and campylognathoidids). However, some early pterosaurs, such as Dimorphodon macronyx and wukongopterids, have glenoid arthrologies which are not ventrally restricted, and their distal humeri resemble those of pterodactyloids. It seems fully erect forelimb stances were possible in these pterosaurs, and may be probable given proposed correlation between pterodactyloid-like distal humeral morphology and forces incurred through erect forelimb postures. Further indications of terrestrial habits include antungual sesamoids, which occur in the manus and pes anatomy of many early pterosaur species, and only occur elsewhere in terrestrial reptiles, possibly developing through frequent interactions of large claws with firm substrates. It is argued that characteristics possibly associated with terrestriality are deeply nested within Pterosauria and not restricted to Pterodactyloidea as previously thought, and that pterodactyloid-like levels of terrestrial competency may have been possible in at least some early pterosaurs.