Wing Phalanx Research Articles

A new pterosaur from the early stage of the Jehol biota in China, with a study on the relative thickness of bone walls

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.

Wing phalanges of a ?thalassodromine pterosaur from the Aptian–Albian Antlers Formation of Texas, USA

Fragmentary pterosaurian wing phalanges from the Aptian-Albian Antlers Formation of north-central Texas, USA are described. Wing phalanges 1 and 2 have suboval shafts with thickened bone at the leading and trailing edges, whereas the third wing phalanx has a flattened airfoil-like cross-section with greatly thickened bone at the leading and trailing edges and a small subrectangular medullary cavity. The cortical bone exhibits an unusual coarse surface texture, and bone thin sections reveal extensive Haversian remodeling and endosteal lamellar bone. The morphology of the wing phalanges differs from that of dsungaripterids, pteranodontoids, and azhdarchids, so the specimen is not a North American record of the Dsungaripteridae as some have stated; whereas based on comparisons to a roughly contemporaneous indeterminate thalassodromine pterosaur specimen from the Romualdo Formation of Brazil, the specimen is tentatively interpreted as an indeterminate thalassodromine with an estimated wingspan of ∼3.5 m.

A new species of Eopteranodon (Pterodactyloidea, Tapejaridae) from the Lower Cretaceous Yixian Formation of China

The Tapejaridae is an exquisite toothless pterodactyloid clade of pterosaurs that flourished in the Jehol Biota with well-developed premaxillary and dentary crests, large nasoantorbital fenestra and downward rostrum. Since Sinopterus dongi has been reported from the Jiufotang Formation, most of the Chinese tapejarids were discovered from this geological unity. Eopteranodon lii, the first tapejarid from the Yixian Formation, was formerly referred to the Pteranodontidae and is now assigned to the Tapejaridae. Here, Eopteranodon yixianensis sp. nov. is reported from this latter formation as differing from all other known tapejarids by largest rostral value (10.88); the nasoantorbital fenestra is not as long as that of other tapejarids (accounting for 35% of the skull length). Furthermore, the skull's length/height ratio is ∼5.67; the lower bony crest occupies ∼42% of the total mandibular length; the humerus and the fourth wing phalanx length ratio is ∼2.17 and the downturn rostral angle is ∼17°. New data on the evolution (morphology and geographical origin) of the group is also provided.

New information on Lonchognathosaurus (Pterosauria: Dsungaripteridae) from the Lower Cretaceous of the southern Junggar Basin (NW China)

Lonchognathosaurus is a poorly known dsungaripterid pterosaur based on a partial skull from the Lower Cretaceous Lianmuxin Formation of the southern Junggar Basin. In 2001, several postcranial elements were recovered close to the holotype skull of Lonchognathosaurus that are referable to the same individual as the holotype material. They comprise a distal carpal, a fourth metacarpal, a partial first phalanx of the wing finger and the complete second phalanx of the wing finger. The postcranial material resembles that of other dsungaripterids but also exhibits numerous differences, mostly concerning the morphology of the distal carpal, the proximal articular surface of the fourth metacarpal and the proximal articular surface of the first wing phalanx. Moreover, Lonchognathosaurus differs from all other dsungaripterids in its wing proportions, being the only dsungaripterid known so far with a shorter metacarpal IV than second wing phalanx. This last character represents an additional autapomorphy of Lonchognathosaurus and confirms the validity of the genus.

An articulated pterosaur wing from the Upper Cretaceous (Maastrichtian) phosphates of Morocco

A new and articulated specimen of a pterosaur wing including the humerus, radius/ulna, parts of the carpus and metacarpus and a first wing phalanx from Maastrichtian phosphatic deposits of Morocco is assigned to Tethydraco regalis Longrich et al., 2018. Aspect of the humerus morphology, shape of the deltopectoral crest and ratios of the wing elements suggest that T. regalis is an azhdarchid rather than pteranodontian pterosaur, as originally proposed. A high abundance of azhdarchid remains in the open marine setting of the Moroccan phosphates casts doubt on suggestions that Azhdarchidae are largely terrestrial pterosaurs.

A new wing skeleton of <i>Forfexopterus</i> (Pterosauria: Ctenochasmatidae) from the Early Cretaceous Jehol Biota reveals a developmental variation

Abstract. In the Jehol Biota, the filter-feeding ctenochasmatid pterosaurs flourished with a high biodiversity. Here, we report a new wing skeleton of the ctenochasmatid Forfexopterus from the Early Cretaceous Jiufotang Formation in Jianchang, western Liaoning, China. The specimen exhibits the sole autapomorphy, the first wing phalanx shorter than the second and longer than the third. Interestingly, it exhibits a skeletal maturity with co-ossified elements, but it is only about 75 % the size of the immature holotype. This discrepancy reveals developmental variation of Forfexopterus, but its relationship with sexual dimorphism needs to be certain by more available material.

An early Oligocene stem Galbulae (jacamars and puffbirds) from southern France, and the position of the Paleogene family Sylphornithidae

AbstractTogether, puffbirds (Bucconidae) and jacamars (Galbulidae) form the suborder Galbulae, sister group of all other Piciformes. Hitherto, the Galbulae had no ascertained pre-Pleistocene fossil record, and all previous alleged candidates have been refuted, except possibly the Sylphornithidae. Here we describe a wing of a tiny fossil bird from the early Oligocene of the Luberon region (southern France), which we assign to the Galbulae, as a new genus and species. Several characters, especially of the ulna and wing phalanx 1 of digit II, exclude the Passeriformes and Zygodactylidae, and indicate a representative of the Piciformes. Among Piciformes, absence of papillae remigales caudales and several characters of the wing phalanx 1 of digit II make it possible to assign the fossil to the Galbulae, and exclude all other clades. The fossil Sylphornithidae, with the carpometacarpus of Sylphornis being available, show some similarity with the Luberon fossil. The combination of features of the wing elements leads to the placement of the new fossil as stem Galbulae, and tentatively within the family Sylphornithidae. As such, it fills a gap and permits to better assign the whole enigmatic tiny sylphornithids, otherwise essentially known from leg bones. This yields the first firm pre-Pleistocene fossil record for the Galbulae. Today, both the Bucconidae and Galbulidae live exclusively in tropical America. The presence of stem Galbulae in the Oligocene of Europe, and probably the late Eocene, is a new example of a present-day Neotropical clade that had stem representatives in the Paleogene of Europe.

경상남도 하동군 하부 백악기 하산동층에서 산출된 익룡 지골 화석

경상남도 하동군 금남면 대도의 해안선에 노출된 중부 하산동층(Aptian)에서 익룡의 네 번째 앞발가락 뼈 일부가 발견됐다. 전기 백악기에 생존했던 아시아 익룡들과의 크기 및 형태 비교를 통해 이 화석을 cf. Boreopteridae로 분류했다. 추정된 발 크기는 같은 층에서 보고된 생흔종 Pteraichnus koreanensis의 것보다 훨씬 크며, 앞뒤 발자국 크기가 서로 비슷한 P. koreanensis와 달리 Boreopteridae의 앞뒤 발자국 크기는 서로 다르기 때문에 하산동층 시기에 최소한 두 종류의 익룡이 공존했음을 보여준다. 이전에 보고된 Boreopteridae는 모두 중국의 하부 백악기 이시안층(Aptian)에서 산출되었기 때문에 이 화석은 중국 밖에서 처음 보고되는 Boreopteridae에 대한 기록임과 동시에 이들의 분포가 남동쪽으로 크게 연장돼있었음을 보여준다. 또한 이 화석은 하성 퇴적층에서 발견됐기 때문에 Boreopteridae가 강 주변에서도 생활했음을 보여준다.

The largest flying reptile from the Crato Formation, Lower Cretaceous, Brazil

ABSTRACTThe Early Cretaceous deposits of the Araripe Basin in northeast Brazil has yielded numerous vertebrate fossils, in which pterosaurs are the predominant tetrapods. Almost all specimens of this extinct group of flying reptiles recovered from this basin come from two stratigraphic units, the Crato and Romualdo Formations, with the pterosaurs from the former being usually small to middle-sized and large individuals (with a maximized wingspan over 5 m) being only found in the latter. Here we report on a new specimen (MPSC R 1221) composed of a partial right wing, which is the largest pterosaur discovered from the Crato Formation so far, having an estimated maximized wingspan of 5.5 m. Despite the incompleteness of this material, MPSC R 1221 can be referred to the Anhangueridae based on the length ratio between the metacarpal IV and the first wing phalanx. According to the osteohistological study and the degree of fusion, MPSC R 1221 represents a sub-adult individual, showing that the animal had not reached the maximum size before its death. The present study shows that large-sized pterosaurs were also present in the Crato Formation and that their rarity might be an artefact of preservation.

Short note on a new anurognathid pterosaur with evidence of perching behaviour from Jianchang of Liaoning Province, China

Abstract A new anurognathid pterosaur, Vesperopterylus lamadongensis gen. et sp. nov., is erected based on a complete skeleton with a skull preserved. It is characterized by two short distinct ridges present on the ventral surface of the cervical vertebrae; coracoids slightly longer than scapula; humerus, wing phalanx 3 and tibia nearly the same in length; grooves clearly present on the posterior surface of the wing phalanges 1–3; and the first toe reversed. It is the first anurognathid pterosaur from China with a definitively short tail, and the first pterosaur with a reversed first toe. The reversed first toe of Vesperopterylus indicates that it had arboreal habitats. The discovery of Vesperopterylus lamadongensis from the Jiufotang Formation strongly expands the geological age range for anurognathid pterosaurs.

A new archaeopterodactyloid pterosaur from the Jiufotang Formation of western Liaoning, China, with a comparison of sterna in Pterodactylomorpha

ABSTRACTEleven species of archaeopterodactyloid pterosaurs have been reported in China, mostly from the Yixian Formation of western Liaoning. The first uncontroversial archaeopterodactyloid from the Jiufotang Formation is described here. A new genus and species, Forfexopterus jeholensis, is erected on the basis of a unique combination of characters and one autapomorphy: the first wing phalanx is shorter than the second, but longer than the third. The sternum of Forfexopterus is nearly complete and provides the first incontrovertible evidence about the position of sternocoracoid articulations in the Archaeopterodactyloidea. A preliminary geometric morphometric analysis of sterna was carried out with data from 17 species of Pterodactylomorpha. The results document the variation in the shape of the sternum, including the length of the cristospine, the shapes of the lateral, posterior, and anterior margins, and the constriction and expansion of the cristospine. These characters can be used to compare sterna in different pterosaur taxa.Citation for this article: Jiang, S., X. Cheng, Y. Ma, and X. Wang. 2016. A new archaeopterodactyloid pterosaur from the Jiufotang Formation of western Liaoning, China, with a comparison of sterna in Pterodactylomorpha. Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2016.1212058.http://zoobank.org/urn:lsid:zoobank.org:pub:41B25239-6220-4006-82CD-1624B36A38EB

New information on the Wukongopteridae (Pterosauria) revealed by a new specimen from the Jurassic of China.

The Wukongopteridae is an important pterosaur group discovered from Yanliao Biota, because it combines character states seen in non-pterodactyloid and pterodactyloid pterosaurs. So far, the Wukongopteridae contains three genera: Wukongopterus, Darwinopterus and Kunpengopterus; representing five species. Here we report on a new specimen, IVPP V 17959, that can be undoubtedly referred to the Wukongopteridae based on the presence of a confluent nasoantorbital fenestra, elongated cervical vertebrae (convergent with Pterodactyloidea) and a long tail enclosed by rod-like bony extensions of the zygapophyses. Traits distinguishing this new specimen from other wukongopterid pterosaurs include a premaxilla with a low ossified anterodorsal crest, a nasal bearing the most elongated process known in the Wukongopteridae, and a lacrimal that has a foramen in its middle portion. The new kind of premaxillary crest preserved in IVPP V 17959 suggests that the presence or absence of a premaxillary crest might be an interspecific feature within the Wukongopteridae. A phylogenetic analysis including all wukongopterid pterosaurs recovers IVPP V 17959 in a polytomy with Wukongopterus and the species of Darwinopterus, having Kunpengopterus in a more basal position. The postcranial skeleton of IVPP V 17959 has ontogenetically mature characteristics including a completely fused scapula and coracoid, fused proximal and distal carpal series, and an ossified extensor tendon process of the first wing phalanx, allowing its classification as ontogenetic stage five. Furthermore, the atlas and axis are separated in IVPP V 17959, which indicates that these two bones probably are not fused in skeletally mature wukongopterid individuals.

Biomechanical and physiological influences on the osteohistological deposition of Anhangueria (Pterosauria, Pterodactyloidea)

The study of bone microstructure preserved in fossils provides substantial information about physiology, growth gradients and strategies, and some ecological considerations. Paleohistology is a useful tool for understanding the biological mechanisms of extinct animals. Presented here is the microstructure characterization of two Anhangueria pterosaurs. Thin sections of the fi rst wing phalanx and metacarpal IV of MN 7060-V have been confectioned, as have sections of the radius, ulna and fi rst wing phalanx of MPSC R2090. The histological analysis of bones of MN 7060-V revealed fi brolamellar tissue, few osteocytes and vascular canals. Bones of MPSC R2090 showed a mixed plexiform-fi brolamellar tissue and histovariability, showing that bones from the same individual grew in different patterns. The vascularization was high in the phalanx, intermediate in the ulna and absent in the radius. The absence of canals in the radius may be related to biomechanical issues, due to torsion resistance during fl ight. The histology and the absence of fused bones suggests that the specimens are not adults. Two distinct moments of growth were established. MN 7060-V is a subadult, with presence of bone porosity and MPSC R2090 is a young animal as determined by the high number of canals and plexiform-fi brolamellar tissues, which indicates fast growth. In this work, we concluded that in the Anhangueria clade, the growth of bones is not compatible with the ontogenetic stage. Young animals may present large proportions, whereas there were older individuals of smaller sizes in the same clade.

New interpretation of the wings of the pterosaurRhamphorhynchus muensteribased on the Zittel and Marsh specimens

AbstractThe Zittel wing ofRhamphorhynchus muensteriis reinterpreted as preserving negative impressions of closely spaced broad flat actinofibrils that were replaced by calcite but were prepared away by the specimen’s finder. The Marsh specimen preserves positive impressions of the dorsal and ventral surfaces of the wing, which show that the skin was smooth with fine wrinkles and that actinofibrils were not on the wing surface. Based on comparisons of those specimens, the dactylopatagium consisted of dorsal and ventral skins of epidermis and dermis surrounding a common hypodermis core, and keratinous actinofibrils developed in place within the dorsal epidermis adjacent to a layer of linear collagen fibers in the dorsal dermis. The actinofibrils and linear collagen fibers together formed the main functional structure of the dactylopatagium. That structure made the dactylopatagium somewhat stiff and essentially inextensible so that it folded up along discrete fold lines that probably were genetically determined. A pneumatic retrophalangeal wedge behind the antebrachium through at least wing phalanx 3 streamlined the transition between the thick wing spar and thin patagium.

Evidence for the presence of Rhamphorhynchus (Pterosauria: Rhamphorhynchinae) in the Kimmeridge Clay of the UK

The second pterosaur genus to be established, Rhamphorhynchusvon Meyer, 1847, has historically been used as a wastebasket material. Several species have been erected for fossils found in Europe and Africa, the majority of which are based on non-diagnostic material. Following Bennett's (1996) review of its taxonomy, Rhamphorhynchus is generally regarded as a monospecific taxon restricted to the Late Kimmeridgian and Tithonian of Southern Germany. Here we describe a disarticulated but complete right pterosaur wing, MJML K-1597 from the Kimmeridge Clay Formation of England. Based on a combination of morphology and statistical analysis, MJML K-1597 can safely be referred to Rhamphorhynchus, making it the first diagnostic Rhamphorhynchus specimen from outside of Germany. Furthermore, based on the unique length ratio between wing phalanx 1 and wing phalanx 2, MJML K-1597 can be referred to a new species of Rhamphorhynchus.

Cretornis hlavaci Frič, 1881 from the Upper Cretaceous of Czech Republic (Pterosauria, Azhdarchoidea)

Cretornis hlavaci Frič, 1881 from the Upper Cretaceous (Turonian) of Czech Republic is a valid taxon referred to Azhdarchoidea based on having a saddle-shaped humeral head, pneumatic foramen on proximal humerus present on anterior side and absent on posterior side, elongate deltopectoral crest with subparallel proximal and distal margins, pneumatic foramen absent on distal side of humerus, metacarpals I–III not articulated with carpus and displaced on anterodorsal side of wing metacarpal, and wing metacarpal much longer than humerus. Absence of a pneumatic foramen on posterior side of proximal humerus suggests attribution of Cretornis hlavaci to Neoazhdarchia. It has a unique construction of the distal ulna with a dorsal articulation surface placed distinctly proximal to the tuberculum shared only with the non-azhdarchid azhdarchoid Montanazhdarcho minor from the Campanian of North America. Cretornis hlavaci differs from the latter taxon by the structure of its humerus and distinctly longer wing metacarpal. It is more derived than “Tapejaridae” but shares with Azhdarchidae the deltopectoral crest of the humerus displaced distally from humeral head. Cretornis cannot be assigned to Azhdarchidae because of the oval cross section of the second wing phalanx. A unique rhombic outline of the distal humerus of Cretornis hlavaci is a possible autapomorphy for this taxon. Its wing span estimated as 1.5–1.6 m. This is the first taxon of non-azhdarchid pterosaurs known from the Upper Cretaceous of the Eastern Hemisphere.

A new rhamphorhynchid pterosaur (Pterosauria) from Jurassic deposits of Liaoning Province, China.

Compared to pterosaurs from the Early Cretaceous from China, Late Jurassic pterosaurs are relatively rare. A new rhamphorhynchid pterosaur, Orientognathus chaoyngensis gen. et sp. nov., is erected based on an incomplete skeleton from the Upper Jurassic Tuchengzi Formation of Chaoyang, Liaoning Province, China. It is identified by the following characters: the toothless tip of the lower jaw is slightly pointed; the length ratio of wing metacarpal to humerus is 0.38, the ulna is shorter than each wing phalanx and the tibia is nearly equal to femur in length. A phylogenetic analysis recovers Orientognathus chaoyngensis as a rhamphorhynchid pterosaur. Orientognathus chaoyngensis is perhaps the youngest Jurassic pterosaur from western Liaoning Province of China.

A New Rhamphorhynchid Pterosaur (Pterosauria) from the Middle Jurassic Tiaojishan Formation of Western Liaoning, China

Abstract:A new Sordes‐like pterosaur Jianchangopterus zhaoianus gen. et sp. nov. is erected based on a almost complete skeleton with skull preserved. It is characterized by the following characters: seven and six pairs of upper jaw and lower jaw teeth respectively; the development of a recess on maxilla; the evenness of the dental margin in lateral view; a distinct central ridge along dorsal surface of the mandibular symphysis; wing phalanx 4 with strongly curved shaft approximately 96% the length of the wing phalanx 1. The discovery of a Sordes‐like pterosaur Jianchangopterus, and other taxa from the same formation indicates that pterosaurs reached great diversities during the Middle to Upper Jurassic period.

CONTROLLED EXCAVATIONS IN THE ROMUALDO FORMATION LAGERSTATTE (ARARIPE BASIN, BRAZIL) AND PTEROSAUR DIVERSITY: REMARKS BASED ON NEW FINDINGS

Because of its fossil abundance and exceptional preservation, the Romualdo Formation of the Santana Group has become a famous lithostratigraphic unit of the Araripe Basin. In the past decades, much research has been conducted on the vertebrates of this unit, especially fish and pterosaurs, based mainly on museum collections. Despite the importance of these fossil finds, no stratigraphic information is known about them, because until recently, locals have collected most of the fossils. Here we present the results of the third controlled excavation of these layers. The data from all fossils collected confirm a faunal succession of fish biota. In the upper and most fossiliferous layer, the faunal composition shows a pattern of fish distribution never observed before, indicating that previous categories (abundance versus diversity) do not include the total diversity of fish populations. Pterosaur remains were recorded for the first time in the field, contradicting the general idea that these volant reptiles are common in the Romualdo strata. The specimen was attributed to the clade Anhangueridae because the proportional length of the first wing phalanx is less than twice the length of the wing metacarpal. The controlled excavation showed that the pterosaur assemblages from this formation probably occur in clusters. The known abundance of pterosaurs in the Romualdo Formation has been biased by just a few sites of fossil extraction, and these reptiles do not appear to have been as widespread or abundant as previously thought.

New pterosaur fossils from the Early Cretaceous (Albian) of Queensland, Australia

ABSTRACT Pterosaur fossils from Australia are rare. All the specimens that have been described previously are Cretaceous in age, with the majority deriving from the Aptian–Albian shallow marine succession within the Eromanga Basin of western Queensland. The Queensland specimens have tentatively been referred to the pterodactyloid clades Pteranodontidae, Ornithocheiridae, and Archaeopterodactyloidea (cf. Ctenochasmatoidea), each in varying taxonomic guises. Due to their fragmentary nature, more specific referrals of these specimens have not been possible. As such, the overall composition and more precise relationships of Australia's Cretaceous pterosaur fauna have remained enigmatic. Since 1987, a number of new pterosaur specimens have been found in the shallow marine late Albian rocks of the Eromanga Basin of western Queensland. Four of these specimens are described herein: a partial mandible, a metacarpal IV, a wing phalanx, and a humerus. The mandible is assigned to Ornithocheiridae, gen. et sp. indet., whereas the metacarpal and wing phalanx are assigned Ornithocheiridae cf. Anhanguera. The morphology of the humerus suggests that it may belong to a ctenochasmatoid lophocratian. Based on these findings, we hypothesize that Australia's Early Cretaceous pterosaur fauna comprises a mix of taxa already known to occur in Europe and South America in addition to a slightly younger ctenochasmatoid. However, the older specimens may alternatively represent new taxa that combine cranial characteristics of an Ornithocheirus-like taxon or a closely related form, with an Anhanguera-like postcranium. A more precise characterization of Australia's Cretaceous pterosaur fauna cannot be resolved until more complete specimens are found.