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New remains of the pterosaur Dimorphodon (Pterosauria: Rhamphorhynchoidea) and the terrestrial ability of early pterosaurs
... The most common and consensual current conclusion suggests that non-pterodactyloid pterosaurs were bad (or no) walkers, but probably good climbers. Anatomical arguments coupled with the lack of non-pterodactyloid tracks reinforce this interpretation (Unwin, 1987(Unwin, , 1988(Unwin, , 1989(Unwin, , 1999(Unwin, , 2006Unwin and Bakhurina, 1994;Bennett, 1997a). Thus, pterodactyloids and non-pterodactyloid pterosaurs could have occupied different environments, with different behaviours, non-pterodactyloids never (or rarely) landing on the ground. ...
... During the debate of the years 1970-90 about the stance and gait of grounded pterosaurs, palaeontologists were divided about the bipedal and quadrupedal hypotheses (Logue, 1977(Logue, , 1994Padian, 1983aPadian, , 1983bPadian and Olsen, 1984;Wellnhofer, 1988;Unwin, 1988Unwin, , 1989. Then, new ichnological evidence was reported, which definitely demonstrated the quadrupedal stance and gait of walking pterodactyloid pterosaurs, that led to the current consensus of semi erect quadrupedal pterodactyloids (Logue, 1977(Logue, , 1994Mazin et al., 1995Mazin et al., , 1997Lockley et al., 1995;Unwin, 1996aUnwin, , 1996bUnwin, , 1999Bennett, 1997bBennett, , 1997aClark et al., 1998). ...
... Two arguments were used to discuss these capabilities. First, several features seem to make the ''rhamphorhynchoids'' best climbers than walkers, with more arboreal than terrestrial behaviours, which should explain the lack of trackways (Unwin, 1987(Unwin, , 1988(Unwin, , 1989(Unwin, , 1996b(Unwin, , 1999(Unwin, , 2006Unwin and Bakhurina, 1994;Bennett, 1997a). A second group of arguments considers the non-pterodactyloids as digitigrade bird-like bipeds, even good runners, with limited motion of the forelimbs which cannot reach the substrate (Padian, 1983a(Padian, , 1983b(Padian, , 1985(Padian, , 2003(Padian, , 2008a(Padian, , 2008b. ...
New discoveries on the ichnological site known as “the Pterosaur Beach of Crayssac” (lower Tithonian, Upper Jurassic; south-western France) answer the question of terrestrial capabilities of non-pterodactyloid pterosaurs. If the terrestrial type of locomotion of pterodactyloid pterosaurs has been solved from ichnological evidence for more than twenty years, no tracks and trackways referable to non-pterodactyloid pterosaurs have ever been described. Thus, the debate on terrestrial capabilities of these non-pterodactyloids was based on morpho-functional studies, with the main conclusion that those pterosaurs were arboreal dwellers and bad walkers. Six trackways referable to three non-pterodactyloid new ichnotaxa, maybe closely related to Rhamphorhynchidae, are described in this work. Their study leads to the conclusion that grounded non-pterodatyloids, at least during the Late Jurassic, were quadrupedal with digitigrade manus and plantigrade to digitigrade pes. They were clearly good walkers, even if hindlimbs are supposed to be hampered by the uropatagium, what could have constrained the terrestrial agility of these animals. Thus, from ichnological evidence and contrary to the current hypotheses, non-pterodactyloid pterosaurs seem to have been good walkers even though their trackways are very rare or unidentified to date. This rarity could be due to behaviour rather than to functional capacities, many non-pterodactyloids being considered both littoral fishers and arboreal or cliff dwellers. However, the concept of non-pterodactyloid “good climbers and bad walkers” has to be modified to “good climbers and rare walkers”, unless many non-pterodactyloid ichnites have yet to be discovered.
... Much ink has been used in the discussion of the orientation of the pterosaur acetabulum with hypotheses ranging from lateral (Wellnhofer, 1975a(Wellnhofer, , 1978Bennett, 2001a:100), lateroventral (Padian, 1983b), laterodorsal (Wellnhofer and Vahldiek, 1986;Unwin, 1987;Wellnhofer, 1988:4), anterodorsal (Unwin, 1988), posterolateral (Bennett, 1990:80;Kellner and Tomida, 2000;Bennett, 2001a:97,99-100), to laterodorsoposterior (Molnar, 1987;Wellnhofer, 1988:3,9;Bennett, 1990;2001a:99). Considering that the point of greatest depth is positioned dorsoanteriorly within the acetabulum of TMM 41954-57, it would be most defensible that the acetabulum of Q. lawsoni is oriented ventroposteriorly. ...
... The pterosaur tarsus consists of four or (more rarely) five elements: two proximal series tarsals and two to three distal series tarsals (Wellnhofer, 1970(Wellnhofer, , 1975b(Wellnhofer, , 1978(Wellnhofer, , 1991bPadian, 2017). The proximal tarsals (astragalus and calcaneum) fuse to the distal end of the tibia early in ontogeny to form the distal condyles of the tibiotarsus (Seeley, 1901;Wellnhofer, 1978;Padian, 1983a;Unwin, 1988;Bennett, 1993;Dalla Vecchia, 2003b). When they are unfused, they are usually a pair of indistinct disk-or lozenge-shaped elements found in juvenile pterosaurs preserved in laminated deposits (e.g., Solnhofen Limestone). ...
Quetzalcoatlus is the largest flying organism ever known and one of the most familiar pterosaurs to the public. Despite a half century of interest, it remains very incompletely described. This shortfall is addressed here through a full morphological description of Quetzalcoatlus and the other pterosaur material of Big Bend National Park, Texas. The first reported material was described and named Quetzalcoatlus northropi by Douglas Lawson in 1975, but in two separate publications. A ruling by the International Commission of Zoological Nomenclature was required for the name to be made available. Review of the pterosaur fauna of the Park recovers three valid species of azhdarchid pterosaurs in the latest Cretaceous Period Javelina and Black Peaks formations. The size and occurrence of these species are correlated with depositional environment. The holotype of the giant Quetzalcoatlus northropi and six other giant specimens referred to it occur in stream-channel deposits, including the youngest reported pterosaur. The vast majority of specimens (200+) are from large pterosaurs found in the abandoned channel-lake deposits at Pterodactyl Ridge; they form a diagnosable natural group erected as the new species Quetzalcoatlus lawsoni. A moderate-sized partial skull and cervical series also found in the abandoned channel-lake deposits at Pterodactyl Ridge, but lower in the section, is distinct from both species and is erected as Wellnhopterus brevirostris, gen. et sp. nov. Overbank flood-plain facies preserve another eleven specimens of extreme size variation, including small azhdarchids. The Big Bend pterosaur fauna provides the greatest known sample of azhdarchid pterosaurs and three-dimensional pterosaur morphology.
... Even though almost the entire specimen is disarticulated, even elements that do not normally come apart like the radius and ulna, metacarpals 1-3, and the pelvic plate have separated, and some of the manual and pedal unguals are still in articulation with the long penultimate phalanges of the digits, suggesting they have incredibly strong ligaments and held these elements in articulation. Strongly curved claws and long penultimate phalanges have been shown to be indicative of a strong grip 28 and suggest that Skiphosoura might have been a good climber, though with no evidence of any antungual sesamoids. Collectively though, this suggests that Skiphosoura might not have favored coastal areas normally and that they typically lived inland, and this matches the interpretation of this fauna from other sources. ...
... Quest'ultimo continua ad essere una creatura fondamentale nella ricerca sugli pterosauri, per esempio per studi sulla postura (Padian, 1983b;Unwin, 1988a;Bennett, 1997;Clark, et al. 1998) e sulle relazioni tra pterosauri e altri rettili (Nesbitt and Hone, 2010). I Dimorphodontidae possono essere descritti come frutto di una radiazione evolutiva iniziale di pterosauri con grandi teste, probabilmente ben adattati per scalare gli alberi. ...
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.
... The terrestrial locomotion of the pterosaurs has been a controversial issue over two hundred years. Some researches stated the bipedal locomotion (Cuvier, 1801(Cuvier, , 1809Padian, 1983;Paul, 1987), other studies argued the quadrupedal locomotion (Soemmerring, 1812;Unwin, 1987Unwin, , 1988Wellnhofer, 1988Wellnhofer, , 1991Unwin, 1999, 2001;Chatterjee and Templin, 2004). However, the discovery of quadrupedal pteosaurian trackways in the Morrison Formation (Stokes, 1957) sheds light on the terrestrial locomotion of these reptiles. ...
Numerous pterosaur traces have been reported from the Jangdong Formation, Hwasun Seoyuri Dinosaur Tracksite, Jeollanam-do Province, Korea. The Jangdong Formation in the Neungju Basin is well-known for abundant dinosaur trackways and study on dinosaur acceleration phase using for the trackways. In this thesis, a detailed description of pterosaurian traces, their paleoecology, and the possible tracemaker of ichnites are conducted using four new pterosaur trace-bearing slabs and two previously reported slabs. The pterosaur tracks in the formation are classified as Pteraichnus isp. and one of the smallest ones in the Late Cretaceous. The pterosaur tracks in Seoyuri are yielding with manus-dominated and randomly oriented in high density. Some tracks are discovered in the states with claw marks. These characters indicate semi-floating behavior with feeding, possibly. The concentrated tracks and variation in size could be interpreted as gregarious behavior or multi-flock of pterosaurs. The considerable tracemaker of the Pteraichnus isp. in Hwasun is very rare in the Late Cretaceous. To date, previous reported small-sized pterosaurs in the Late Cretaceous are included in ornithocheiroidea and only discovered in North America (British Colombia, and Montana) and Arabia (Lebanon), but not in East Asia. Therefore, the tracemaker of the Pteraichnus isp. in Hwasun would be not reported ornithocheiroidea, inhabited in the Late Cretaceous Korean Peninsula. This global distribution of small-sized pterosaurs could interpret as their deficiency in the store of a lineage related to the lack of the contemporary Lagerstätten in the Late Cretaceous.
... the proximal articulation is expanded and the portion of the bone that might have been interpreted as the deltopectoral crest is triangular. Based on the anatomy of Dimorphodon humeri (e.g., Wellnhofer 1978, Padian 1983, Unwin 1988, the shaft is curved, differing from the straight bone reported from Antarctica. In Dimorphodon, the deltopectoral crest is longer, does not extend as deep on the shaft and is not triangular. ...
Fossil vertebrates from Antarctica are considerably rare, hampering our understanding of the evolutionary history of the biota from that continent. For several austral summers, the PALEOANTAR project has been carrying out fieldwork in the Antarctic Peninsula in search for fossils, particularly Cretaceous vertebrates. Among the specimens recovered so far are two bones referable to Pterosauria, more specifically to the Pterodacyloidea, the first volant reptiles from Antarctica to be fully described. MN 7800-V (part and counterpart) was recovered from a moraine at the Abernathy Flats (Santa Marta Formation, Lachman Crags Member, Santonian-Campanian) on James Ross Island. It is interpreted as the distal articulation of a first phalanx of the wing finger, representing an animal with an estimated wingspan between 3 and 4 m. The second specimen (MN 7801-V) comes from Vega Island (Snow Hill Island Formation, Maastrichtian) and is identified as a wing metacarpal IV of an animal with an estimated wingspan from 4 to 5 m. These occurrences show that pterodactyloids inhabited the Antarctic Peninsula at least during the Upper Cretaceous and demonstrate that large pterosaurs were widespread through all parts of the planet during that period.
... C. hanseni differs from D. macronyx in numerous ways (Fig. 4b,c). In D. macronyx: (1) the jugal process of the maxilla ends anterior to the posterior margin of the antorbital fenestra, and the suture between the maxilla and jugal is vertical and sigmoid 16 ; (2) the jugal does not contribute to the antorbital fossa 16,24,33 ; (3) the orbit faces laterally and deeply notches the jugal 16 ; (4) the orbit shape is an inverted tear drop 16 ; (5) the frontoparietal is more elongated than in C. hanseni 16 ; (6) the nasal is comparatively shorter and triangular, with an anteriorly directed premaxillary process 16 ; (7) the surangular dorsal process is a small, blunt point (BMNH 43486); and (8) there is no longitudinal furrow along the posterior margin of the wing phalanges 34 . ...
... C. hanseni differs from D. macronyx in numerous ways (Fig. 4b,c). In D. macronyx: (1) the jugal process of the maxilla ends anterior to the posterior margin of the antorbital fenestra, and the suture between the maxilla and jugal is vertical and sigmoid 16 ; (2) the jugal does not contribute to the antorbital fossa 16,24,33 ; (3) the orbit faces laterally and deeply notches the jugal 16 ; (4) the orbit shape is an inverted tear drop 16 ; (5) the frontoparietal is more elongated than in C. hanseni 16 ; (6) the nasal is comparatively shorter and triangular, with an anteriorly directed premaxillary process 16 ; (7) the surangular dorsal process is a small, blunt point (BMNH 43486); and (8) there is no longitudinal furrow along the posterior margin of the wing phalanges 34 . ...
Pterosaurs are the oldest known powered flying vertebrates. Originating in the Late Triassic, they thrived to the end of the Cretaceous. Triassic pterosaurs are extraordinarily rare and all but one specimen come from marine deposits in the Alps. A new comparatively large (wing span >150 cm) pterosaur, Caelestiventus hanseni gen. et sp. nov., from Upper Triassic desert deposits of western North America preserves delicate structural and pneumatic details not previously known in early pterosaurs, and allows a reinterpretation of crushed Triassic specimens. It shows that the earliest pterosaurs were geographically widely distributed and ecologically diverse, even living in harsh desert environments. It is the only record of desert-dwelling non-pterodactyloid pterosaurs and predates all known desert pterosaurs by more than 65 Myr. A phylogenetic analysis shows it is closely allied with Dimorphodon macronyx from the Early Jurassic of Britain.
Dimorphodon macronyx (Buckland, 1829) is one of the earliest known Jurassic pterosaurs and the first English pterosaur to have been formally described; the original specimens from the London Natural History Museum have not been fully reviewed since Richard Owen’s monograph of 1870. This monograph provides a detailed, comparative osteological description and emended diagnosis of D. macronyx, based primarily on the four key London and British Geological Survey specimens, and supplemented by the other known skeletal material. Previously undescribed palatal bones uncovered in one of the Natural History Museum specimens (NHMUK 41212) in 2002 are also described and a tentative reconstruction of the palate presented. A short review of previous phylogenetic studies on the taxonomic status of D. macronyx is provided.
We reconstruct the proportions and possible motions of the skeleton of the giant azhdarchid pterosaur Quetzalcoatlus. The neck had substantial dorsoventral mobility, and the head and the neck could swing left and right through an arc of ca. 180°. In flight, it is most plausible that the hind limbs were drawn up bird-like, with the knee anterior to the acetabulum. In this position, an attachment of the wing membrane to the hind limb would have been useless. A straight-legged posterior extension of the hind limb, such as rotation of the hind limb into a fully ‘bat-like’ pose, was likely prevented by soft tissues of the hip joint. Given these difficulties, the traditional ‘broad-winged’ bat-like restoration is unrealistic. On the ground, Quetzalcoatlus, like other ornithodirans, had an erect stance and a parasagittal gait. Terrestrial locomotion was powered almost entirely by the hind limbs. The pace length would have been limited to the length of the glenoacetabular distance, except that Quetzalcoatlus (like other pterodactyloids) had a unique gait in which the forelimb was elevated out of the way of the hind limb from step to step. If the humerus were retracted 80° and adducted nearly to the body wall, the elbow and wrist may have been able to extend to effect a quadrupedal launch with assistance from the hind limbs, assuming sufficient long bone strength and sufficient extensor musculature at these forelimb joints. A bipedal launch using the hind limbs alone also appears plausible: despite the animal’s great size, the hind limb to torso length ratio is the greatest for all known pterosaurs.
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