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New specimens of Pterosauria (Reptilia) with soft parts with implication for pterosaurian anatomy and locomotion
Abstract
New specimens of pterosaurs with soft-part preservation from the Solnhofen Lithographic Limestone (S Germany) and the Crato Formation (northeastern Brazil) yield hitherto unknown and unexpected details of pterosaur anatomy: the presence and internal anatomy of soft-tissue crests, the internal anatomy of the brachiopatagium, including a blood vessel system and structural details of foot and hand. Some consequences for pterosaurian flight, thermoregulation and aspects of evolution are discussed.
... Notably, the Neoazhdarchia (sensu Unwin 2003) are remarkable for hyper-elongation of their cervical vertebrae, such that some forms likely had a neck of ∼3 m long (Nesov 1984(Nesov , 1991Frey and Martill 1996;Andres and Langston 2021). Also in the postcranial skeleton, there are important differences to be seen in the scapulocoracoid and humerus that likely reflect significant differences in their mode of flight (Frey et al. 2003a). Similarly, there are differences seen in the relative lengths of elements of the wing skeleton, especially in the proportions of metacarpal IV that also likely reflect differences in their mode of flight (Kellner and Tomida 2000;Martill et al. 2013;Smith et al. 2023a). ...
... Although crests on the skull (cranium, upper jaws, lower jaws) are a feature of some pterosaurs from the Triassic (see Dalla Vecchia 2014) and Jurassic (e.g. Frey et al. 2003a), head crest diversity is most notable in Cretaceous forms (Fig. 6). The first crested pterosaur to become well known in popular media is the iconic Pteranodon of the Kansas chalk formations (Marsh 1871(Marsh , 1872(Marsh , 1876(Marsh , 1884 of the USA. ...
... Today, head crests have been reported for almost all clades of Cretaceous pterosaurs. In a few cases, where bony crests have not been detected, soft tissue crests have been found in some exceptionally preserved examples, notably Tapejaridae from the Aptian Crato Formation of Brazil (Frey et al. 2003a, b;Kellner and Campos 2007), or when specimens have been examined using UV radiation (Frey et al. 2003a). Crests have been reported located on the premaxillae, maxillae, dentaries and parietals (Wellnhofer 1987;Campos and Kellner 1997;Martill and Naish 2006;Vullo et al. 2012), almost always medially in position. ...
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 anterior most point of the crest has a noticeable depression where the grain of the bone tracks this ( Figure 6C) and so it appears to be a quite natural furrow where the crest joins to the rostrum. This might represent some kind anchor for the soft tissue expansion which was surely present here as seen on many other pterosaurs with similar cranial crests (e.g., see Frey and Martill, 1998;Frey et al., 2003) ...
... These include crests composed solely of soft tis-sues, combinations of soft tissues and bone, and potentially those made only of bone (Witton, 2013). The striated sagittal crest on the rostrum of Petrodactyle is similar to that borne by a number of other ctenochasmatoid taxa (e.g., see Buffetaut et al., 1998;Frey et al., 2003;Bennett, 2013b, Figure 13), and others including non-pterodactyloid monofenestratans (Lü et al., 2011), Germanodactylus (Bennett, 2006) and Hamipterus (Wang et al., 2014). In at least some cases, these striated crests support preserved soft tissues crests that can be considerably larger than the supporting bony structure (e.g., Frey and Martill, 1998;Bennett, 2013a). ...
... A number of ctenochasmatids also bear a soft tissue crest at the back of the skull, often termed the occipital cone or lappet (Frey et al., 2003, Bennett, 2013a, which in some may have integrated with the soft tissue crest attached to the top of the rostrum (Frey et al., 2003, though see Bennett, 2013b. However, this seems unlikely in Petrodactyle as there is no simple rounded posterior face to the skull as seen in e.g., Pterodactylus. ...
... They first appeared in the Late Triassic and were highly diverse, with substantial morphological disparity and taxonomic richness until the end of the Late Cretaceous (Benton and Pfretzschner, 2007;Longrich et al., 2018). Since their first scientific description in the late eighteenth century (Collini, 1784), pterosaur fossils have been known preserving not only hard parts (e.g., skeletal remains), but in extraordinary cases also soft parts that provide insights into their palaeobiology (e.g., Goldfuß, 1831;Zittel, 1882;Bennett, 2000, Tischlinger andFrey, 2002;Frey et al., 2003;Wellnhofer, 2008;Kellner et al., 2010;Witton, 2013). Although a variety of soft tissues are preserved in the pterosaur fossil record (including skin and internal organs), two types of soft parts appear to be unique to the group, warranting background discussion. ...
... The presence or absence of aktinofibrils distinguish two areas of the pterosaur wing (Kellner et al., 2010), with the proximal portion lacking them, but with the distal portion (aktinopatagium) showing a striking radiating pattern in a posterodistal direction (Schaller, 1985;Wellnhofer, 1987;Bennett, 2000;Tischlinger and Frey, 2002;Frey et al., 2003;Chatterjee and Templin, 2004;Kellner et al., 2010;Witton, 2013;Bennett, 2015;Hone et al., 2015). Aktinofibrils were densely packed in the wing (Kellner et al., 2010) and are hypothesised to have increased the stability of the distal wing region despite their exceedingly small diameter (only 0.05-0.2 ...
... Individual aktinofibrils ran parallel to each other with a distance of ~0.2 mm to each other (Wellnhofer, 1975c(Wellnhofer, , 1987Tischlinger and Frey, 2002;Chatterjee and Templin, 2004). Their diameter and length do not seem to have remained constant within the wing membrane, as they decreased in the medial direction (Frey et al., 2003;Bennett, 2015). Aktinofibrils were probably rather rigid structures that maintained their length even when the wing was folded or stretched (Bennett, 2000;Witton, 2013). ...
... The South America pterosaur record is undoubtedly the most diverse and well-researched Gondwanan pterosaur assemblage, with members of the Raeticodactylidae, Ctenochasmatidae, Gnathosaurinae, Nyctosauridae, Ornithocheiridae, Tapejaridae, Thalassodromidae, Dsungaripteridae and Azhdarchidae represented Martínez et al., 2022;Perea et al., 2018;Soto et al., 2021). The majority of specimens are derived from Cretaceous sedimentary rocks deposited in the Araripe Basin of Brazil, which has yielded numerous partial skeletons (Elgin and Frey, 2012) and specimens preserving softtissues (Campos et al., 1984;Campos and Kellner, 1997;Campos et al., 2017;Frey and Martill, 1994;Frey et al., 2003b;Frey et al., 2003c;Kellner, 2004;Martill and Unwin, 1989). The South American pterosaur assemblage has also been fundamental to augmenting our understanding of pterodactyloid head crest morphology (Campos and Kellner, 1997;Wellnhofer and Kellner, 1991) and wing membrane extent (Campos et al., 1984;Frey and Martill, 1994;Frey et al., 2003c). ...
... The majority of specimens are derived from Cretaceous sedimentary rocks deposited in the Araripe Basin of Brazil, which has yielded numerous partial skeletons (Elgin and Frey, 2012) and specimens preserving softtissues (Campos et al., 1984;Campos and Kellner, 1997;Campos et al., 2017;Frey and Martill, 1994;Frey et al., 2003b;Frey et al., 2003c;Kellner, 2004;Martill and Unwin, 1989). The South American pterosaur assemblage has also been fundamental to augmenting our understanding of pterodactyloid head crest morphology (Campos and Kellner, 1997;Wellnhofer and Kellner, 1991) and wing membrane extent (Campos et al., 1984;Frey and Martill, 1994;Frey et al., 2003c). ...
... The most significant South American pterosaur localities are the Lower Cretaceous Santana and Crato lagerstätten of Brazil, which have yielded diverse and abundant pterosaur remains. Exceptional preservation of soft tissues provides rare insights into particular aspects of pterosaur anatomy, as exemplified by the cranial crests of tapejarids (Campos and Kellner, 1997;Campos et al., 2017;Frey et al., 2003b), the wing membrane (Campos et al., 1984;Frey and Martill, 1994;Frey et al., 2003c), and brachiopatagium (Frey et al., 2003c;Kellner, 2004;Martill and Unwin, 1989). The former sheds light on the extremes of pterosaur cranial anatomy and evokes discussions regarding pterosaurian display, whereas the latter more accurately constrains the aerodynamics of flight. ...
The Gondwanan pterosaur record is scarce when compared with that of Laurasia and is reviewed here. The majority of Gondwanan pterosaur remains are derived from South America; however, the relative richness of the South American record compared with other Gondwanan continents is largely a result of the ‘Lagerstätten’ effect. Nevertheless, the South American pterosaur assemblage represents the most speciose and diverse known from Gondwana, with several lineages represented, including the Raeticodactylidae, Rhamphorhynchoidea, Darwinoptera, Ctenochasmatidae, Gnathosaurinae, Nyctosauridae, Ornithocheiridae, Tapejaridae, Thalassodromidae, Dsungaripteridae, Chaoyangopteridae and Azhdarchidae. Gondwanan pterosauromorphs are known only from South America. From Africa rhamphorhynchids, archaeopterodactyloids, pteranodontians, nyctosaurids, ornithocheirids, tapejarids, dsungaripteroids, chaoyangopterids, and azhdarchids have been reported. The Arabian Peninsula has produced nyctosaurids, an istiodactyliform, ornithocheirids and azhdarchids. Non-pterodactyloid pterosaurs have been reported from India. A possible azhdarchid has been reported from Madagascar and rhamphorhynchids are known from isolated teeth. The Antarctic pterosaur assemblage also comprises isolated remains of indeterminate pterodactyloids, and a possible indeterminate rhamphorhynchoid. The pterosaur record from East Gondwana comprises ornithocheirids, azhdarchids and a possible ctenochasmatoid from Australia, as well as azhdarchids from New Zealand. Although our understanding of Gondwanan pterosaurs has greatly improved within the last three decades, the discovery and description of more specimens, particularly from Antarctica and East Gondwana, will enhance our understanding of pterosaurian biodiversity and palaeobiogeography.
... A manus-dominated trackway at Glendo occurs at the top of the Windy Hill Sandstone and is capped by weathered claystone and siltstone, indicating accumulation in a lagoon or pond. Manus prints are 5.5-10 cm long and exhibit three laterally to caudally splayed fingers with no claw impressions, suggesting the unguals were held in a retracted position (see Frey et al., 2003) possibly as the pterosaurs punted along the bottom while buoying up their bodies. Pes tracks are typically 8-11 cm long with an average of 9 cm, these correspond to a wingspan of approximately 1.5-1.8 ...
... They exhibit four toes with digital pads, claws and possible webbing. A circular heel pad is the deepest part of some prints as reported in other such examples from the Upper Jurassic of Crayssac, France and Asturia, Spain (Frey et al., 2003;Mazin et al., 1995). The medial and lateral metatarsal form deeper impressions than the central two metatarsals, which indicates a slight longitudinal arch similar to the specimens from France and Spain, but different from the type specimens from Arizona, USA described by Stokes (1957). ...
An enigmatic transition from the storm‐dominated, offshore to lower shoreface deposits of the Redwater Shale Member (Sundance Formation) to the overlying mixed tidal and aeolian Windy Hill Sandstone (Morrison Formation) in the Oxfordian of the North American Western Interior has long been a source of intrigue. Previously proposed drivers include the progradation of a large, tide‐dominated delta onto a storm‐dominated shelf, a complete reorganisation of the basin's hydrodynamics and climate, or the development of a regional unconformity (termed the J‐5). In south‐eastern Wyoming, the Redwater Shale is characterised as an offshore to distal shoreface deposit with glauconitic siltstones and sandstones punctuated by coquinoid and sandy tempestites and hosting a Cruziana Ichnofacies. The Windy Hill Sandstone, a time‐transgressive, sand‐rich, intertidal succession with classic Pteraichnus and stressed Skolithos Ichnofacies, sharply overlies the Redwater Shale and records an abrupt basinward shift in facies that accompanied at least tens of metres of sea‐level fall. New, detailed sedimentological, ichnological and architectural data collected across this transition in the study area provide fresh insights into the depositional history of these units and demonstrates the existence locally of a composite J‐5 unconformity. The unconformity developed as tectonically driven, prograding shoreline trajectories of the Redwater Shale gave way to degrading trajectories of the Windy Hill Sandstone, leading to a forced regression and formation of a regressive surface of marine erosion. The sharp juxtaposition of intertidal flat facies (Pteraichnus Ichnofacies) directly upon offshore to lower shoreface deposits (Cruziana Ichnofacies) is the key to recognising the unconformity and proves the value of the previously underutilised ichnological data.
... In our dataset, the R/t ratios of dsungaripterids and non-pterodactyloids do not reach the threshold; and six archaeopterodactyloids specimens, including Pterodactylus, Germanodactylus, and three ctenochasmatids, have R/t-ratios around this threshold (Table S1). An aquatic or semi-aquatic lifestyle is rather possible than a fossorial lifestyle for archaeopterodactyloids, because of their food (such as fish, hard-shelled invertebrates, and small aquatic creatures [76]) and the interdigital webbing in some taxa [77][78][79]. The thick bone walls of creatures in this lifestyle are generally interpreted to pertain to decreased buoyancy in water [73,75]. ...
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.
... In addition, wing planform and flight performance could be highly dynamic, as modern birds use in-flight wing morphing for transition between stable and unstable states and thereby dynamically trade between flight efficiency and manoeuvrability [54]. This would certainly have been possible in pterosaurs given the muscle fascia layer in the wing membranes and the ability to move both the fore-and hindlimbs at various joints [1,55]. ...
Pterosaurs evolved a broad range of body sizes, from small-bodied early forms with wingspans of mostly 1–2 m to the last-surviving giants with sizes of small airplanes. Since all pterosaurs began life as small hatchlings, giant forms must have attained large adult sizes through new growth strategies, which remain largely unknown. Here we assess wing ontogeny and performance in the giant Pteranodon and the smaller-bodied anurognathids Rhamphorhynchus, Pterodactylus and Sinopterus. We show that most smaller-bodied pterosaurs shared negative allometry or isometry in the proximal elements of the fore- and hindlimbs, which were critical elements for powering both flight and terrestrial locomotion, whereas these show positive allometry in Pteranodon. Such divergent growth allometry typically signals different strategies in the precocial–altricial spectrum, suggesting more altricial development in Pteranodon. Using a biophysical model of powered and gliding flight, we test and reject the hypothesis that an aerodynamically superior wing planform could have enabled Pteranodon to attain its larger body size. We therefore propose that a shift from a plesiomorphic precocial state towards a derived state of enhanced parental care may have relaxed the constraints of small body sizes and allowed the evolution of derived flight anatomies critical for the flying giants.
... UV imaging methods have been used successfully in the study of fossils from the Franconian Jura including pterosaurs, clarifying as well as revealing for the first time a wide and hitherto unknown range of osteological and soft tissue information (Frey et al. 2003a;Tischlinger 2002;Tischlinger and Frey 2013). Notably, soft tissue head crest structures have been discovered in Pterodactylus sp. as has webbing between the toes (Frey et al. 2003b). ...
A new long-legged, spatula-beaked, filter-feeding pterodactyloid pterosaur from Upper Jurassic plattenkalk limestones at Wattendorf, Bavaria, Southern Germany, is remarkable for its completeness, unusual dentition and hints of the preservation of soft tissues, including wing membranes. The fully articulated specimen displays both jaws each side with over one hundred sub-parallel-sided teeth with a small, slightly hooked expansion at the crown tip. There are at least 480 teeth in total. The tip of the rostrum widens to a spatula-like, laterally concave structure with teeth only along its lateral margins. The straight anterior margin is devoid of teeth allowing plankton-rich water to stream in, while the teeth interdigitate forming a fine mesh trap. A slightly up swept rostrum assisted filtering by probable pulsating movements of the long neck, while wading or swimming through shallow water.
... Among these are the world famous Konservat-Lagerstätten (sense Seilacher, 1970;Seilacher et al., 1985;Itano, 2019) recorded in the Aptian Crato and Romualdo formations of the Santana Group, Araripe Basin (Maisey, 1991;Martill et al., 2007;Varejão et al., 2019a;Ribeiro et al., 2021) and the Upper Jurassic-Lower Cretaceous Muzinho Shale, Patos Bons Formation, Parnaíba Basin (Cardoso et al., 2020). Thanks to their exceptional preservation, many of the fossils have significantly contributed to our understanding of the paleobiology of various groups, including pterosaurs (Kellner, 1984;Frey and Martill, 1994;Campos and Kellner, 1997;Frey et al., 2003aFrey et al., , 2003bWitton, Freitas et al. (2017). C. Detail of the sedimentary succession of the Amargosa Bed in the Tucano Basin, according to Freitas et al. (2017) and Varejão et al. (2019b). ...
We report the Amargosa Biota from the middle part of the Lower Cretaceous Marizal Formation (Central Tucano Sub-Basin, NE Brazil), as a new Konservat-Lagerstätte. Exceptionally preserved fossils are confined to the lower part of an up to 15-m-thick, mud-dominated succession, named Amargosa Bed. Seven bedding planes (L0-L6) with distinct sedimentological and taphonomic attributes were identified in the type section (Amargosa Village, Euclides da Cunha County, Bahia State), distributed in an ~1-m-thick succession of well-laminated claystone, mudstone, siltstone, and very fine-grained sandstone. These contain ostracods, spinicaudatan carapaces, palaemonid shrimps, fish, and comminuted plant remains. Fossils occur in high concentration on at least four bedding planes (i.e., L2, L3, L5, and L6), forming polytypical assemblages that are dominated by one of the fossil groups. Assemblages are formed mainly by autochthonous to parautochthonous elements, representing variable, but limited, temporal mixing. A key attribute of some fossil-rich strata (L3, L5, and L6) is the preservation of poorly biomineralized organisms and/or of complete soft-bodied parts, which are typically prone to destruction due to rapid decay or bioturbation. The polytypical nature of these fossil assemblages, interbedded with non-fossiliferous intervals, suggests mass mortality events, probably caused by abrupt changes in water parameters (anoxia, salinity, pH, among others). The dark greenish gray color (yellowish when weathered), and the finely laminated nature of the claystone, siltstone, and mudstone containing members of the Amargosa Biota indicates that the benthic infaunal life was absent or, at least, very scarce in a locally, relatively deep, oxygen-poor lake bottom. Anoxia and high salinity, linked with local semi-arid conditions during the Lower Cretaceous may have played key roles in the exceptional preservation of some fossils (shrimps, fish). Finally, our data provide a more comprehensive understanding of the temporal distribution of taxa and taphonomic processes associated with the complex genesis of the fossil-bearing interval of the Amargosa Bed in its type locality.
Pterosaurs thrived in and around water for 160 + million years but their take-off from water is poorly understood. A purportedly low floating position and forward centre of gravity barred pterosaurs from a bird-like bipedal running launch. Quadrupedal water launch similar to extant water-feeding birds and bats has been proposed for the largest pterosaurs, such as Anhanguera and Quetzalcoatlus. However, quadrupedal water launch has never been demonstrated in smaller pterosaurs, including those living around the Tethys Sea in the Late Jurassic Solnhofen Lagoon. Using Laser-Stimulated Fluorescence, we singled out aurorazhdarchid specimen MB.R.3531 that alone preserved specific soft tissues among more than a dozen well-preserved Solnhofen pterosaur specimens. These soft tissues pertain to primary propulsive contact surfaces needed for quadrupedal water launch (pedal webbing and soft tissues from an articulated forelimb) that permit robust calculations of its dynamic feasibility without the need to make assumptions about contact areas. A first-principles-based dynamics model of MB.R.3531 reveals that quadrupedal water launch was theoretically feasible and that webbed feet significantly impacted launch performance. Three key factors limiting water launch performance in all pterosaurs are identified, providing a foundation for understanding water launch evolution: available propulsive contact area, forelimb extension range and forelimb extension power about the shoulder.
New specimens of pterosaurs from the Solnhofen Lithographic Limestone (Upper Jurassic, Bavaria, Germany) and the Crato-Formation (Lower Cretaceous, Ceará, north east Brazil) with spectacular soft-part preservation are described. The feet of a Pterodactylus preserve scaly heel pads, webbing between the toes and extremely long claw sheaths. An azhdarchid from the Lower Cretaceous from Brazil shows identical structures. For the first time the detailed structure of the webbing in a Pterodactylus is reported. Fibres in the dorsal skull area of the Pterodactylus and an undescribed tapejarid from Brasil hint on the presence of cranial crests which consist completely (Pterodactylus) or mainly (Tapejaridae indet.) of soft tissue.
The Cambridge Greensand, a remanié deposit that crops out in Cambridgeshire, eastern England, has yielded numerous, though fragmentary, late Early Cretaceous (Albian) vertebrate fossils including more than 2000 isolated pterosaur bones. So far, 32 species of pterosaur have been proposed in connection with the Cambridge Greensand material, but there has been and continues to be considerable confusion concerning the validity of these taxa, their relationships to each other and to other pterosaurs, and the material upon which they were established. A comprehensive systematic revision identified eleven valid species distributed among three families: the Ornithocheiridae (Ornithocheirus simus and possibly a second, as yet unnamed species of Ornithocheirus, Coloborhynchus capito, Coloborhynchus sedgwickii, Anhanguera cuvieri, and Anhanguera fittoni); the Lonchodectidae (Lonchodectes compressirostris, Lonchodectes machaerorhynchus, Lonchodectes microdon and Lonchodectes platystomus); and a species of edentulous pterosaur (Ornithostoma sedgwicki) that may represent the earliest record for the Pteranodontidae. It is possible that some of the taxa currently recognised represent sexual dimorphs (Coloborhynchus capito and Coloborhynchus sedgwickii, Lonchodectes compressirostris and Lonchodectes machaerorhynchus), or disjunct populations of a single species (Ornithocheirus simus and Ornithocheirus sp., Lonchodectes compressirostris and Lonchodectes microdon) and that there may be as few as seven valid species, but the Cambridge Greensand pterosaurs are too poorly known to demonstrate this at present. The Cambridge Greensand pterosaur assemblage is similar to a slightly younger, but much smaller assemblage from the Lower Chalk of England and shares some elements, such as ornithocheirids, in common with many other late Early and early Late Cretaceous assemblages. It is distinguished by the absence of tapejarids and the presence of Lonchodectes which, so far, is only known from the Cretaceous of England. The disparity in taxonomic composition is possibly related to ecological differentiation, and might also reflect some provincialism in late Early and early Late Cretaceous pterosaur faunas.
Der Cambridge Greensand, eine in Ostengland aufgeschlossene Remanié-Ablagerung, hat zahlreiche Wirbeltiere aus der oberen Unterkreide (Alb) geliefert. Darunter fanden sich mehr als 2000 isolierte Pterosaurierknochen. Insgesamt wurden aus dem Greensand bis zu 32 Flugsauriertaxa beschrieben, was zu einer beträchtlichen taxonomischen und nomenklatorischen Verwirrung geführt hat, die bis heute andauert. Eine vollständige Revision erkennt 11 Arten aus drei Familien an: (1) die Ornithocheiridae (Ornithocheirus simus und vielleicht eine zweite, bislang unbenannte Art von Ornithocheirus, sowie Coloborhynchus capito, Coloborhynchus sedgwickii, Anhanguera cuvieri und Anhanguera fittoni); (2) die Lonchodectidae (Lonchodectes compressirostris, Lonchodectes machaerorhynchus, Lonchodectes microdon und Lonchodectes platystomus); und schließlich einen zahnlosen Flugsaurier (Ornithostoma sedgwicki). der zu keiner der vorgenannten Familien gehört und sich als stratigraphisch ältester Nachweis der Pteranodontidae erweisen könnte. Es ist nicht auszuschließen, dass einige der gegenwärtig erkannten Taxa eher einen ausgeprägten Sexualdimorphismus illustrieren denn taxonomisch distinkte Arten darstellen (Coloborhynchus capito und Coloborhynchus sedgwickii, Lonchodectes compressirostris und Lonchodectes machaerorhynchus) oder sogar lediglich Endpunkte einer intraspezifisch variablen Population (Ornithocheirus simus und Ornithocheirus sp., Lonchodectes compressirostris und Lonchodectes microdon). In dieser strengeren Fassung bestünden nur sieben gültige Arten, doch leider sind die Flugsaurier des Cambridge Greensand zu schlecht bekannt, um diese Fragen zu beantworten. Die Flugsaurierfauna des Cambridge Greensand ähnelt jüngeren kreidezeitlichen Faunen aus dem Lower Chalk von England. Weiter-hin enthält sie Faunenelemente, wie etwa Ornithocheiriden. die auch für zahlreiche andere Faunen der hohen Unterkreide und tiefen Oberkreide charakteristisch sind. Das Fehlen von Tapejariden und das Auftreten des anscheinend endemischen Lonchodectes sind weitere Kennzeichen des Cambridge Greensand. Die Zusammensetzung der Pterosaurierfaunen folgte offenbar ökologischen Differenzierungen und illustriert einen gewissen Provinzialismus an der Grenze Unter-Oberkreide.
doi:10.1002/mmng.20010040112
The specimen consists of a complete skull, the first one reported from the Crato Member, of a new species, Tapejara imperator n.sp. It displays a remarkable sagittal crest that doubles the length and increases in about six times the height of the skull. The upper and main portion of the crest is formed by soft tissue that is supported anteriorly and posteriorly by long strips of bone. This crest, never before reported in any vertebrate, most likely was a display structure, but due to its size it must also had some aerodynamic effect during flight.