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A new pterosaur (Ctenochasmatidae, Archaeopterodactyloidea) from the Lower Cretaceous Yixian Formation of China
Abstract
A partial skeleton (including skull, mandible and soft tissue) of a new archaeopterodactyloid pterosaur, Gegepterus changi gen. et sp. nov. from the Lower Cretaceous of Liaoning, northeast China is described. The specimen, IVPP V 11981, was collected from grey shales of the lower Yixian Formation (125 Ma) at the Sihetun locality, near the city of Beipiao. Several elements (cranial bones, scapula-coracoid) are not fused, suggesting that it probably represents a sub-adult individual at the time of death. Soft tissue is found near the posterior region of the skull, inside the orbit and associated with the gastralia. It is formed of an amorphous dark mineralized substance and does not show any particular structure except in an area at the posterior part of the skull where small, dark, unbranched fibres are present. Gegepterus changi shows synapomorphies of the Archaeopterodactyloidea sensu Kellner, 2003 (elongated mid-cervical vertebrae with low, blade-like neural spine and strongly inclined quadrate) and shares with the Gallodactylidae and the Ctenochasmatidae a concave dorsal margin of the skull. It further has a large number of thin, needle-like teeth and a long rostrum (anterior to the nasoantorbital fenestra) allowing its allocation to the Ctenochasmatidae, thus making it the first uncontroversial member of this pterosaur clade in the Jehol Group. Gegepterus changi is diagnosed by several unique features (e.g., extensive sculpturing of frontals; anterior lacrimal process overlying the nasal; neural spine with knob-like dorsal expansion) and has cervical vertebrae that combine primitive and derived features (e.g., cervical ribs, postexapophyses, lateral pneumatic foramen) that have not been recorded in any member of Archaeopterodactyloidea so far.
... The proximal end of the coracoid has a strongly concave articulation with a posterior expansion ( Fig. 3D and E). The coracoid does not have an expansion at its contact with the scapula, distinguishing it from other archaeopterodactyloids, such as Pterodactylus, Gegepterus, Elanodactylus, and Forfexopterus [26,[28][29][30]. The coracoid process (or biceps tubercle) is less prominent than other pterosaurs, such as Kunpengopterus [31], Hamipterus [32], Anhanguera [33], and Dsungaripterus [34], but taphonomic crushing can result in the partial absence of this process. ...
... Hence, the presence of this large pneumatic foramen can be considered one of the autapomorphies of this new taxon. Additionally, the coracoid has an expansion at its contact with the scapula, as in Gegepterus, Elanodactylus, and Forfexopterus [26,29,30]. This expansion is absent in the new taxon (Fig. 1), which is another autapomorphy. ...
... Huanhepterus also had a short anterior margin, which was misinterpreted as the posterior margin previously [38]. The preserved part of the sternal plate of Gegepterus was quite similar to that of Cratonopterus [29], and the only difference was that the posterior margin of the former was straighter than that of the latter. The four main postcranial ratios of Cratonopterus can be used to distinguish it from most ctenochasmatids, except for E. prolatus (Table 1). ...
... Based on these new observations, we provide a detailed osteological description and modify the diagnosis of M. zhuiana Skull The skull is low and extremely elongated in lateral view (Fig. 1). The dorsal margin of the skull (excluding the premaxillary crest) is nearly straight, varying with some archaeopterodactyloids, such as Gegepterus (Wang et al., 2007), Ctenochasma (Fabre, 1976), and Pterodaustro (Chiappe et al., 2000). The orbit in this specimen is incomplete (Figs. 2, 3), and the opening identified as the orbit in the previous literature probably actually corresponds to the lacrimal fenestra (Lü et al., 2012). ...
... The rostral part of the skull is extremely elongated, occupying about two thirds of the skull length (Table 1). Its rostral index (sensu Martill and Naish, 2006) and rostral value (sensu Kellner, 2017) are 0.077 and 23.32, respectively, which is similar to some other ctenochasmatids, such as Gegepterus, Ctenochasma elegans SMNS 81803, and Ctenochasma taqueti MMSD 75-1671 (Wellnhofer, 1970;Wang et al., 2007;Bennett, 2021). ...
... Although the surface of the crest is unknown, its dorsal margin is straited, indicating that a soft extension could have been present when the pterosaur was alive. A similar crest was also reported in Feilongus, Gegepterus, and Huanhepterus, which also starts at the anterior region of the rostrum and ends anterior to the anterior margin of nasoantorbital fenestra (Dong, 1982;Wang et al., 2005Wang et al., , 2007. The crest of Huanhepterus, however, is not as low as that of M. zhuiana (Dong, 1982). ...
Moganopterus zhuiana Lü et al., 2012 was erected as a member of the Boreopteridae, which was questioned by different researchers shortly after the publication. Although the new assignment to the Ctenochasmatidae is widely accepted by pterosaur researchers, some characteristics still require a detailed description. Here, the holotype of this taxon is restudied, and some ambiguous characteristics are re-identified. The diagnosis of this taxon has been revised as the following: a large ctenochasmatid pterosaur, which can be distinguished from other members of this clade by a single autapomorphy: an elongated rod-like parietal crest that extends posterodorsally, forming an angle of about 15° with the ventral margin of the skull. This taxon can be further distinguished from other ctenochasmatids on the basis of the following combination of characteristics: straight occlusal surfaces of the upper and low jaws; presence of a low premaxillary crest confined anterior to the nasoantorbital fenestra; rostrum about two thirds of the skull length; nasoantorbital fenestra occupying slightly more than 20% of the skull length; about 100 slender teeth; and a mid-cervical length/width ratio of about 7. The wingspan of M. zhuiana has been re-estimated according to a simple regression equation for wingspan versus skull length in ctenochasmatids. It confirms that M. zhuiana, although smaller than previous thought, is still the largest known ctenochasmatid. When comparing the sizes of ctenochasmatids in the Jurassic and Cretaceous, ctenochasmatids showed a rough tendency to increase their sizes.
... Elongated vertebrae, with low, rectangular neural spines, and compressed neural arches are present especially in the clade Ctenochasmatidae. This group includes species such as Gegepterus changae Wang et al., 2007, Elanodactylus prolatus Andres and Ji, 2008, Pterodaustro guinazui Bonaparte, 1970, Beipiaopterus chenianus Lü, 2003, Ctenochasma taqueti Bennett, 2007, Eosipterus yangi Ji and Ji, 1997, and Huanhepterus quingyangensis Dong, 1982, which are characterized by having long compressed snouts, with fine, very closed spaced teeth. A similar morphology to that described in vertebrae of the Ctenochasmatidae is observed in the Azhdarchidae, although in this group the neural arch is completely confluent with the vertebral centrum, forming a single tubular structure (Buffetaut et al., 1997;Martill et al., 1998;Unwin, 2003;Andres and Ji, 2008;Rodrigues et al., 2011;Buffetaut, 2012). ...
... The presence of postexapophyses is a common feature in the Ornithocheiroidea (sensu Bennett, 1994;Kellner, 2003), and has been described in several azhdarchids (Andres and Ji, 2008;Andres et al., 2014;Lü et al., 2016). However, the postexapophyses are also present in some ctenochasmatids such as Gegepterus changi (Wang et al., 2007;Jiang and Wang, 2011) and Elanodactylus prolatus (Andres and Ji, 2008), although they seem to be absent in Ctenochasma gracile (Howse, 1986) and Beipiaopterus chenianus (Lü, 2003). In Gegepterus changi, the presence of cervical postexapophyses is one of the main features that suggest that this species is derived within the Archaeopterodactyloidea (Wang et al., 2007). ...
... However, the postexapophyses are also present in some ctenochasmatids such as Gegepterus changi (Wang et al., 2007;Jiang and Wang, 2011) and Elanodactylus prolatus (Andres and Ji, 2008), although they seem to be absent in Ctenochasma gracile (Howse, 1986) and Beipiaopterus chenianus (Lü, 2003). In Gegepterus changi, the presence of cervical postexapophyses is one of the main features that suggest that this species is derived within the Archaeopterodactyloidea (Wang et al., 2007). Some authors have proposed that the independent acquisition of postexaphopyses in the Ctenochasmatidae and Azhdarchidae is related to the strengthening and restriction of movement of the neck in large taxa, or those with a very long neck (Williston, 1897;Bennett, 2001;Andres and Ji, 2008). ...
We describe a new locality with ctenochasmatid pterosaurs found in a tidal estuarine paleoenvironment of the Quebrada Monardes Formation (Lower Cretaceous). The new locality, which is named "Cerro Tormento", is in Cerros Bravos in the northeast Atacama region, Northern Chile. Here, we describe four cervical vertebrae, one of them belonging to a small individual, the impression of a right scapulocoracoid, a left coracoid, an impression of a left humerus, an incomplete left humerus, a distal fragment of the right humerus, and impressions of a left femur and tibiotarsus. The presence of three humeri and a cervical vertebra belonging to a small pterosaur indicate that these materials represent more than one individual. The cervical vertebrae present diagnostic traits shared with ctenochasmatid pterosaurs, such as elongated vertebral centra, with integrated neural arch, low neural spines, and dorsally located neural canal. It is currently not possible to determine if there are one or more species represented. This finding is the second geographic occurrence of pterosaurs of the clade Ctenochasmatidae in the Atacama region, and although it is currently uncertain if ctenochasmatids from both locations were contemporaneous. This suggests that at least one species of the clade Ctenochasmatidae was widespread in what is now northern Chile. In addition, the presence of bones belonging to more than one individual preserved in Cerro Tormento suggest that pterosaur colonies were present at the southwestern margin of Gondwana during the Lower Cretaceous.
... These pterosaurs lived from the Upper Jurassic to the late Lower finos dientes similares a agujas (Martill et al., 2006). A partir de esta morfología, se ha inferido que los miembros de este grupo probablemente se alimentaban de pequeños organismos acuáticos los cuales atrapaban mediante filtración del agua, la que era posible gracias a sus dientes, los cuales son finos y se disponen muy juntos, de una manera similar a como se alimentan los actuales flamencos (Wellnhofer, 1991;Unwin, 2006 Meyer, 1834;Bonaparte, 1970;Dong, 1982;Harris y Carpenter, 1996;Jouve, 2004;Wang et al., 2007;Jiang y Wang, 2011a, b). También existe referencia a la existencia de ctenocasmátidos en África, específicamente en Tanzania, aunque por ahora esta identificación se encuentra en duda (Andres y Ji, 2008;Costa et al., 2015). ...
... También existe referencia a la existencia de ctenocasmátidos en África, específicamente en Tanzania, aunque por ahora esta identificación se encuentra en duda (Andres y Ji, 2008;Costa et al., 2015). Unos años después, Alarcón-Muñoz et al. (2020) Bonaparte,1970;Dong, 1982;Harris and Carpenter, 1996;Jouve, 2004;Wang et al., 2007;Jiang and Wang, 2011a, b). There is also reference to the existence of ctenochasmatids in Africa, specifically in Tanzania, although for now this identification is in doubt (Andres and Ji, 2008;Costa et al., 2015). ...
... There is also reference to the existence of ctenochasmatids in Africa, specifically in Tanzania, although for now this identification is in doubt (Andres and Ji, 2008;Costa et al., 2015). In addition, in one of these vertebrae the neural spine is preserved, which is very low, while the tipo de tejido blando (Chiappe et al., 2000, Wang et al., 2007. Esta Calama. ...
In this contribution, we present an updated summary of the
knowledge about the pterosaurs that inhabited what is now
Chilean territory. These animals were very diverse during the
Mesozoic. While pterosaurs ruled the sky, dinosaurs occupied
firm land, and an impressive diversity of reptiles occupied the
aquatic environment. Their great diversity is demonstrated
by the extensive fossil record that we currently have of these
animals, which spans all continents, including Antarctica.
However, much of what we currently know about pterosaurs
comes from fragmentary bones, which often do not allow
us to have a clear overview of aspects as diverse as their
appearance, behavior and evolutionary history. Favorably, an
increasing number of specialists have begun to give a new
impetus to the study of pterosaurs, and Chile is not left out. In
our country, the findings are scarce and fragmentary. However,
this is compensated by the extraordinary scientific value that
these specimens possess. So far, four locations with pterosaur
findings are known in Chile. The first of them corresponds to
Quebrada La Carreta, in the Cordillera Domeyko, Antofagasta
Region, a locality where the first remains of a pterosaur were
discovered in Chile, found in Lower Cretaceous rocks, and
which allowed the description of the only species recognized
to date in our country: Domeykodactylus ceciliae. Two other
localities correspond to Cerro La Isla and Cerros Bravos, both in
the Atacama Region, in which Lower Cretaceous rocks outcrop.
The presence of pterosaur bones in Cerro La Isla has been
known since the late 1980s. In this place, a large accumulation
of bones has been described, which belong to at least one
indeterminate species of the clade Ctenochasmatidae. On
the other hand, in Cerros Bravos, a new deposit has recently
been located, which has been named “Cerro Tormento” by
its discoverers. Future studies will be able to answer several
questions concerning the origin of the site and the identity of
the pterosaurs preserved in it. Finally, in the vicinity of Calama,
the remains of what is so far the oldest pterosaur found in
our country were discovered in Upper Jurassic rocks. Recent
studies have shown that this specimen possesses characters
that allow its referral to Rhamphorhynchidae, a group of longtailed pterosaurs that until before this discovery had only been
recorded in the northern hemisphere. The presence of this
group of pterosaurs in these latitudes, and the fauna that lived
with it, constitute a body of evidence that indicates that, at the
end of the Jurassic, the faunal connection between the faunas
of Laurasia and Gondwana was relatively constant. It is very
possible that future prospects in the old and new locations will
deliver more surprises helping to understand about the ancient
dragons that dominated the skies of what is now Chile.
... Despite this, it is worth noting that the primitive pterosaur condition remains equivocal, and pterosaurs may well have developed their integument along pathways that were independent of those seen in other ornithodirans. For example, most pterosaurs with soft tissue remains lack scales on their bodies and had naked leathery skin Unwin 2006;Wang et al. 2007;Kellner et al. 2010). Although some taxa (specifically anurognathids) had pycnofibres, these are not common (see Sect. 12.2;Kellner et al. 2010). ...
... Kellner et al. 2010;Sullivan et al. 2014). These indicate that pterosaur skin was, at least in large part, naked and leathery, and that it lacked scales over most of the body surface (Martill and Unwin 1989;Kellner 1996;Lü 2002;Wang et al. 2007;Kellner et al. 2010). The absence of scales appears genuine, as many of the specimens with soft tissue preservation possess other features with similar preservation potential as scales: details of actinofibres in the wing membranes, keratinous crests, rhamphothecae, claw sheaths, shell membranes, and pycnofibres (e.g. ...
... Sharov 1971), but this implies homology with mammalian fur, which was rejected on both phylogenetic and structural grounds: the term pycnofibre was proposed as an alternative (Kellner et al. 2010). These structures have a wide distribution within the clade and have been documented in a variety of taxa, including the Late Triassic Eudimorphodon (Wild 1993), anurognathids (Sharov 1971;Wang et al. 2002;Kellner et al. 2010), ctenochasmatids (Lü 2002;Wang et al. 2007;Jiang and Wang 2011;Lü et al. 2012), rhamphorhynchids (e.g. Padian 2008; Bennett 2015), pterodactylids (e.g. ...
Feathers are a characteristic of modern birds that differentiate them from all other extant non-avian reptiles. The origin of feathers goes back deep into the Mesozoic, preceding the origin of flight, and early protofeathers were probably present in the ancestral Tetanurae, Dinosauria, or even Ornithodira. Among extant vertebrates, the feathers of modern birds are morphologically the most complex integumentary structure with enormous shape diversity resulting from a hierarchical organization of repetitive morphological and developmental modules. In this chapter, the morphological ground patterns of modern feathers, their underlying developmental processes, and the biological roles of different feather types are reviewed.
... Despite this, it is worth noting that the primitive pterosaur condition remains equivocal, and pterosaurs may well have developed their integument along pathways that were independent of those seen in other ornithodirans. For example, most pterosaurs with soft tissue remains lack scales on their bodies and had naked leathery skin Unwin 2006;Wang et al. 2007;Kellner et al. 2010). Although some taxa (specifically anurognathids) had pycnofibres, these are not common (see Sect. 12.2;Kellner et al. 2010). ...
... Kellner et al. 2010;Sullivan et al. 2014). These indicate that pterosaur skin was, at least in large part, naked and leathery, and that it lacked scales over most of the body surface (Martill and Unwin 1989;Kellner 1996;Lü 2002;Wang et al. 2007;Kellner et al. 2010). The absence of scales appears genuine, as many of the specimens with soft tissue preservation possess other features with similar preservation potential as scales: details of actinofibres in the wing membranes, keratinous crests, rhamphothecae, claw sheaths, shell membranes, and pycnofibres (e.g. ...
... Sharov 1971), but this implies homology with mammalian fur, which was rejected on both phylogenetic and structural grounds: the term pycnofibre was proposed as an alternative (Kellner et al. 2010). These structures have a wide distribution within the clade and have been documented in a variety of taxa, including the Late Triassic Eudimorphodon (Wild 1993), anurognathids (Sharov 1971;Wang et al. 2002;Kellner et al. 2010), ctenochasmatids (Lü 2002;Wang et al. 2007;Jiang and Wang 2011;Lü et al. 2012), rhamphorhynchids (e.g. Padian 2008; Bennett 2015), pterodactylids (e.g. ...
Several stem birds, such as Confuciusornithidae and Enantiornithes, were characterized by the possession of one or two pairs of conspicuous, elongated tail feathers with a unique morphology, so-called rhachis-dominated racket plumes. In the past, several studies reported contradictory interpretations regarding the morphology of these feathers, which sometimes failed to match with any morphology known from modern feathers. In this chapter, these interpretations are reviewed and compared with various modern feather types. The comparison confirms recent interpretations that the rhachis-dominated racket plumes are highly modified pennaceous feathers with ornamental function, originating at least two times independently from each other during evolution. While the gross organization (i.e., a short distal vane and a long, naked rhachis) of these feathers resembles that of filoplumes, they resemble pennaceous body feathers of penguins in terms of rhachis morphology and pigmentation pattern. As the rhachis-dominated racket plumes combine different morphologies that are apparent among modern feather types, this extinct morphotype does in fact not show any aberrant morphological novelties, but rather fall into the morphological and developmental spectrum of modern feathers.
... Kellner et al. 2010;Sullivan et al. 2014). These indicate that pterosaur skin was, at least in large part, naked and leathery, and that it lacked scales over most of the body surface (Martill and Unwin 1989;Kellner 1996;Lü 2002;Wang et al. 2007;Kellner et al. 2010). The absence of scales appears genuine, as many of the specimens with soft tissue preservation possess other features with similar preservation potential as scales: details of actinofibres in the wing membranes, keratinous crests, rhamphothecae, claw sheaths, shell membranes, and pycnofibres (e.g. ...
... Kellner et al. 2010). The abdominal skin of Gegepterus was described as 'rugose' (Wang et al. 2007), but it is not clear if this represents the degraded remains of scales or a different, wrinkled epidermal structure. Several specimens demonstrate that scales were not completely lost in pterosaurs, however, as they were recorded in footpads around the heel (Frey et al. 2003). ...
... Sharov 1971), but this implies homology with mammalian fur, which was rejected on both phylogenetic and structural grounds: the term pycnofibre was proposed as an alternative (Kellner et al. 2010). These structures have a wide distribution within the clade and have been documented in a variety of taxa, including the Late Triassic Eudimorphodon (Wild 1993), anurognathids (Sharov 1971;Wang et al. 2002;Kellner et al. 2010), ctenochasmatids (Lü 2002;Wang et al. 2007;Jiang and Wang 2011;Lü et al. 2012), rhamphorhynchids (e.g. Padian 2008Bennett 2015), pterodactylids (e.g. ...
Over the last two decades, the dinosaur fossil record has revealed much about the nature of their epidermal structures. These data challenged long-standing hypotheses of widespread reptile-like scalation in dinosaurs and provided additional evidence that supported the deeply nested position of birds within the clade. Moreover, in recent years, the discovery of filamentous structures in numerous species across the dinosaurian evolutionary tree suggests a model of deep feather homology within dinosaurs, with the appearance of feathers hypothesised to coincide with the dinosaur origin. Thanks to phylogenetic comparative methods, these homologies can now be tested empirically and form the basis of this study. Based on a dataset of 77 dinosaur species that preserve integumentary structures, we undertake a series of model-fitting and ancestral state reconstruction analyses to interpret the evolutionary history and ancestral integumentary condition in dinosaurs. Our results provide the first empirical support for the evolution of feathers in an ordered fashion, but reveal that these evolutionary trends were not always towards ‘more complex’ conditions. Ancestral state reconstructions demonstrate that irrespective of the preferred phylogenetic framework, the ancestral pterosaur condition or whether any one major dinosaur lineage had a Late Triassic-feathered representative, support values for a filamentous/feathered dinosaur ancestor are low. More examples of feathered taxa from across the dinosaur tree, and in particular the discovery of as yet unknown feathered Triassic taxa, will be needed in order to overturn current support for a scaly dinosaurian ancestor.
... In palatal view, several dental bases and alveoli without teeth are visible, aligned in a single row at the labial margins of the element. The orientation of the dental crown bases on the left side suggests that the fragment likely corresponds to the anterior portion of the rostrum, since the teeth in this region tend to be anteriorly (He et al., 1983;Jouve, 2004;Lü and Ji, 2005;Wang et al., 2007;Jiang and Wang, 2011a, b). Five alveoli are present on the right border, which lack teeth. ...
... The bases of the dental crowns show a gradual change in diameter along the anteroposterior axis of the element, which may indicate their relative position in the tooth row. In Gegepterus changae for example, the alveoli decrease in diameter posteriorly (Wang et al., 2007;Jiang and Wang, 2011a). Counting from the proposed posterior end, the fifth alveolus does not preserve any trace of the crown, while the fourth dental base seems to correspond to a replacement tooth based on its lack of a pulp cavity. ...
... The teeth in the Chilean remains are set in alveoli as in Ctenochasma, without clear evidence of a longitudinal groove (Wellnhofer, 1970;Buisonj e, 1981). This is different from the condition in Gegepterus changae (Wang et al., 2007) where the premaxillary, maxillary and dentary teeth are held in deep alveoli arranged in a longitudinal groove flanked by bony walls, the thicker corresponding to the labial border and the thinner to the lingual. ...
New pterosaur remains from Cerro La Isla, Quebrada Monardes Formation (Lower Cretaceous), Northern Chile, are reported and described. The material comprises mandibular remains preserving dental bases and two vertebrae of the mid cervical series. The morphology and arrangement of the preserved dental bases of the pterosaurs of Cerro La Isla show a similar pattern to that observed in European and Chinese ctenochasmatids, but are different from those of the Argentinian and Uruguayan ctenochasmatids from South-America. On the other hand, the new vertebrae share certain characteristics with the mid cervical vertebrae of ctenochasmatid pterosaurs, such as very elongated centra with low neural arches, low and elongated neural spines, the presence of postexapophyses and a pair of oval pneumatic foramina on the lateral surfaces of the vertebral centra. Although most of these features are shared with the midcervical vertebrae of azhdarchid pterosaurs, the lower integration of the neural arch, which does not acquire a tubular morphology in the mid-point of the vertebral centrum, together with the presence of oval pneumatic foramina, are characteristics that allow the referral of both vertebrae to the pterosaur family Ctenochasmatidae. The vertebral, mandibular and rostral remains from Cerro La Isla suggest the presence of a previously unknown ctenochasmatid pterosaur, different from the only other South American taxon. This new discovery not only increases the diversity of
this clade, but also helps to better understand the evolution of this group in Southwestern Gondwana.
... Bonde & Christiansen 2003), some archaeopterodactyloids (e.g. Wang et al. 2007 foramen has been found to pierce the lateral surface of the centrum of a mid-cervical vertebra in the Chinese tapejarine Sinopterus dongii (Vila Nova et al. 2015). Eopteranodon and Eoazhdarcho were reported to also lack these lateral foramina (Zhou 2010), but these taxa do not exhibit laterally preserved cervical vertebrae (Lü & Ji 2005;Lü & Zhang 2005;Lü et al. 2006a) and therefore the presence of such foramina cannot be verified. ...
... Kellner 2003;Wang et al. 2014). As a notable exception, the unusual archaeopterodactyloid Gegepterus changi (Yixian Formation, Early Cretaceous of China) is the only non-dsungaripteroid exhibiting postexapophyses (Wang et al. 2007). However, the mid-cervical vertebrae of this form can be distinguished from those of chaoyangopterids and azhdarchids due to the presence of pneumatic foramina on the lateral surface of the centrum (Wang et al. 2007). ...
... As a notable exception, the unusual archaeopterodactyloid Gegepterus changi (Yixian Formation, Early Cretaceous of China) is the only non-dsungaripteroid exhibiting postexapophyses (Wang et al. 2007). However, the mid-cervical vertebrae of this form can be distinguished from those of chaoyangopterids and azhdarchids due to the presence of pneumatic foramina on the lateral surface of the centrum (Wang et al. 2007). ...
The Brazilian Crato Formation (Lower Cretaceous, Aptian) is well known for its rich pterosaur fauna. This paper deals with a new find represented by four articulated mid-cervical vertebrae.
The vertebrae show a morphology consistent with that seen in the Chaoyangopteridae, especially the relative elongation, low neural spines, lack of pneumatic foramina on the lateral face of
the centra and the presence of well-developed postexapophyses. Chaoyangopterids are, so far, represented with confidence only in Chinese deposits; the only record outside the Jehol Group is the
Crato Formation form Lacusovagus magnificens, a partial skull whose assignment to the Chaoyangopteridae has been disputed. Given this controversy, we review the phylogenetic position of Lacusovagus,
and discuss the nesting of our new specimen among theChaoyangopteridae, providing some comments concerning the composition of the group. We conclude that our new specimen provides further support for the presence of chaoyangopterids in the Early Cretaceous of Brazil.
... As with dinosaurs and many other clades, pterosaurian evolution took place against a backdrop of profound changes in palaeogeography driven by the fragmentation of Pangaea, major fluctuations in sea level and shifts in climatic zones. It is therefore surprising that there has been very little detailed study of pterosaurian biogeographical history (though see Unwin 1996;Wang et al. 2005Wang et al. , 2007Wang et al. , 2012. This neglect may reflect the intense focus on the flight mechanics of these organisms, and/or the implicit assumption that the geographical distributions of flying organisms are affected more by specific ecological requirements rather than large-scale vicariance and coherent dispersal patterns. ...
... the relationships of these taxa are different in Figure 1, and their closest relatives are also from East Asia, Feilongus and Nurhachius still cluster with European taxa. This biogeographical scenario was reinforced by Wang and Zhou (2006) and Wang et al. (2007) who argued that representatives of the clades Anurognathidae, Rhamphorhynchidae, Gallodactylidae, Ornithocheiridae, Pterodactylidae and Ctenochasmatidae were present in the Late Jurassic of Europe but absent from Asia until the Early Cretaceous. These authors inferred one or more dispersal events from Europe to East Asia, during the Early Cretaceous, as a result of the disappearance of geographical barriers. ...
... anurognathids and ctenochasmatids) from Europe to East Asia during the Barremian-Aptian (as seen in the Yixian Formation), (2) the origin of new groups such as tapejarids and advanced pteranodontoids in East Asia in the Aptian-Albian (e.g. in the Jiufotang Formation) and (3) dispersal of these new groups to South America in the Albian (e.g. Wang and Zhou 2003;Wang et al. 2005Wang et al. , 2007Wang et al. , 2012Witton 2008). Aspects of this scenario, however, are contradicted by our current knowledge of the stratigraphical and geographical distributions of pterosaurs. ...
The biogeographical history of pterosaurs has received very little treatment. Here, we present the first quantitative analysis of pterosaurian biogeography based on an event-based parsimony method (Treefitter). This approach was applied to a phylogenetic tree comprising the relationships of 108 in-group pterosaurian taxa, spanning the full range of this clade's stratigraphical and geographical extent. The results indicate that there is no support for the impact of vicariance or coherent dispersal on pterosaurian distributions. However, this group does display greatly elevated levels of sympatry. Although sampling biases and taxonomic problems might have artificially elevated the occurrence of sympatry, we argue that our results probably reflect a genuine biogeographical signal. We propose a novel model to explain pterosaurian distributions: pterosaurs underwent a series of ‘sweep-stakes’ dispersal events (across oceanic barriers in most cases), resulting in the founding of sympatric clusters of taxa. Examination of the spatiotemporal distributions of pterosaurian occurrences indicates that their fossil record is extremely patchy. Thus, while there is likely to be genuine information on pterosaurian diversity and biogeographical patterns in the current data-set, caution is required in its interpretation.
... The first archaeopterodactyloid pterosaur to be reported from China was Huanhepterus quingyangensis from the Lower Cretaceous Huanhe Formation (Dong, 1982;Wang et al., 2014a). Most archaeopterodactyloids discovered in the Jehol Biota, including Eosipterus yangi, Beipiaopterus chenianus, Zhenyuanopterus longirostris, Boreopterus cuiae, Feilongus youngi, Gegepterus changae, Elanodactylus prolatus, Pterofiltrus qiui, and Boreopterus giganticus, come from the lower part of the Yixian Formation (Ji and Ji, 1997;L€ u, 2003L€ u and Ji, 2005;Wang et al., 2005Wang et al., , 2007Andres and Ji, 2008;Jiang and Wang, 2011a;Jiang et al., 2014), the absolute age of which is 125 Ma (Swisher et al., 2002). Cathayopterus grabaui and Gladocephaloideus jingangshanensis are from the middle and upper parts of the Yixian Formation (Wang and Zhou, 2006;L€ u et al., 2012a), with absolute ages of 122 and 121 Ma (Smith et al., 1995), respectively. ...
... Each of the anterior teeth is located within an alveolus, and the last few teeth are located in a groove formed by their alveoli. The surface of each tooth is smooth, and no longitudinal striations can be observed, similar to the tooth morphology in many ctenochasmatids such as Ctenochasma elegans, Cathayopterus, Gegepterus, and Pterofiltrus (Wagner, 1861;Wang and Zhou, 2006;Wang et al., 2007;Jiang and Wang, 2011a). Nonetheless, the teeth of HM V20 curve more strongly than those of other ctenochasmatids. ...
... Nonetheless, the teeth of HM V20 curve more strongly than those of other ctenochasmatids. Additionally, the number of teeth is similar to that of Huanhepterus, Gnathosaurus, Plataleorhynchus, Boreopterus, and Pterofiltrus (Dong, 1982;Howse and Milner, 1995;L€ u and Ji, 2005;Jiang and Wang, 2011a), but there are fewer teeth than in Cathayopterus and Gegepterus (Wang and Zhou, 2006;Wang et al., 2007), and more teeth than in Feilongus, Gladocephaloideus, and Moganopterus (Wang et al., 2005;L€ u et al., 2012a, 2012b. The tooth row ends anterior to the anterior margin of the nasoantorbital fenestra, which is similar to Huanhepterus, Cathayopterus, and Gegepterus (Dong, 1982;Wang and Zhou, 2006;Wang et al., 2007), but is a longer tooth row than in Feilongus, Gladocephaloideus, and Moganopterus (Wang et al., 2005;L€ u et al., 2012a, 2012b, and a shorter one than in Gnathosaurus, Pterodaustro, Ctenochasma, and boreopterids (Meyer, 1834;Sanchez, 1973;L€ u and Ji, 2005;Bennett, 2007;L€ u, 2010;Jiang et al., 2014). ...
Eleven 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 i...
... Therefore, the shape of the orbit is uncertain, but it is appears to be piriform, because of the sharp angle formed by two processes of the jugal. This condition is not present in Boreopterus cuiae (Lü and Ji, 2005) and most other archaeopterodactyloids such as Feilongus (Wang et al., 2005), Gegepterus (Wang et al., 2007), and Pterodaustro (Chiappe et al., 2000). ...
... One of the large foramina is near the dorsal margin of the lacrimal, and it contains two other small foramina. The other large foramen is at the posterior position, just like the lacrimal foramen in some other pterosaurs, such as Feilongus (Wang et al., 2005) and Gegepterus (Wang et al., 2007). On the posterior side of this foramen position, an apparently unique process directed posteriorly in the orbit is present. ...
... That condition is also present in B. cuiae (Lü and Ji, 2005), Zhenyuanopterus (Lü, 2010), and some archaeopterodactyloids, like Pterofiltrus (Jiang and Wang, 2011), and Ctenochasma (Bennett, 2007). However, a different state occurs in Feilongus (Wang et al., 2005) and Gegepterus (Wang et al., 2007). ...
A new species of boreopterid pterosaur from the new fossil locality, Heichengzi, Beipiao, western Liaoning, China allows a reassessment of the Boreopteridae. In this new analysis, three species, Boreopterus cuiae, Boreopterus giganticus n. sp., and Zhenyuanopterus longirostris, are included within the Boreopteridae united by the autopomorphic occurrence of two main tooth morphologies, an equal length of the tibia and femur, and weak feet. Other taxa previously placed within the Boreopteridae are not in a monophyletic group with the former three species. Boreopterus has fewer teeth and a shorter tooth row than that in Zhenyuanopterus. This new Boreopterus species has a large size, a piriform orbit, an extensively fenestrated lacrimal, and a posteriorly directed lacrimal process, that differs from Boreopterus cuiae.
... As with dinosaurs and many other clades, pterosaurian evolution took place against a backdrop of profound changes in palaeogeography driven by the fragmentation of Pangaea, major fluctuations in sea level and shifts in climatic zones. It is therefore surprising that there has been very little detailed study of pterosaurian biogeographical history (though see Unwin 1996;Wang et al. 2005Wang et al. , 2007Wang et al. , 2012. This neglect may reflect the intense focus on the flight mechanics of these organisms, and/or the implicit assumption that the geographical distributions of flying organisms are affected more by specific ecological requirements rather than large-scale vicariance and coherent dispersal patterns. ...
... the relationships of these taxa are different in Figure 1, and their closest relatives are also from East Asia, Feilongus and Nurhachius still cluster with European taxa. This biogeographical scenario was reinforced by Wang and Zhou (2006) and Wang et al. (2007) who argued that representatives of the clades Anurognathidae, Rhamphorhynchidae, Gallodactylidae, Ornithocheiridae, Pterodactylidae and Ctenochasmatidae were present in the Late Jurassic of Europe but absent from Asia until the Early Cretaceous. These authors inferred one or more dispersal events from Europe to East Asia, during the Early Cretaceous, as a result of the disappearance of geographical barriers. ...
... anurognathids and ctenochasmatids) from Europe to East Asia during the Barremian-Aptian (as seen in the Yixian Formation), (2) the origin of new groups such as tapejarids and advanced pteranodontoids in East Asia in the Aptian-Albian (e.g. in the Jiufotang Formation) and (3) dispersal of these new groups to South America in the Albian (e.g. Wang and Zhou 2003;Wang et al. 2005Wang et al. , 2007Wang et al. , 2012Witton 2008). Aspects of this scenario, however, are contradicted by our current knowledge of the stratigraphical and geographical distributions of pterosaurs. ...
The biogeographical history of pterosaurs has received very little treatment. Here, we present the first quantitative analysis of pterosaurian biogeography based on an event-based parsimony method (Treefitter). This approach was applied to a phylogenetic tree comprising the relationships of 108 in-group pterosaurian taxa, spanning the full range of this clade's stratigraphical and geographical extent. The results indicate that there is no support for the impact of vicariance or coherent dispersal on pterosaurian distributions. However, this group does display greatly elevated levels of sympatry. Although sampling biases and taxonomic problems might have artificially elevated the occurrence of sympatry, we argue that our results probably reflect a genuine biogeographical signal. We propose a novel model to explain pterosaurian distributions: pterosaurs underwent a series of ‘sweep-stakes’ dispersal events (across oceanic barriers in most cases), resulting in the founding of sympatric clusters of taxa. Examination of the spatiotemporal distributions of pterosaurian occurrences indicates that their fossil record is extremely patchy. Thus, while there is likely to be genuine information on pterosaurian diversity and biogeographical patterns in the current data-set, caution is required in its interpretation.
... Among the most interesting fossils recovered from the Jehol deposits are pterosaurs. Some specimens of these extinct flying reptiles have integumentary structures (Wang et al. 2002) and other soft tissue (e.g., Lü 2002;Wang et al. 2007), contributing to our knowledge of their external and internal anatomy for so long restricted to limited material from a few localities (e.g., Unwin & Bakhurina 1994;Kellner 1996;Frey et al. 2003). Up to date, 22 species were described from the Yixian and Jiufotang formations, some of which have been recently questioned (Wang et al. 2005;Wang & Zhou 2006;Lü & Ji 2006). ...
... From the 24 pterosaur taxa of the Yixian and Jiufotang Formations (Wang et al. 2005(Wang et al. , 2007(Wang et al. , 2008Wang & Zhou 2006;Lü & Ji 2006;Andres & Ji 2006;, three have been referred to the Istiodactylidae-Nurhachius ignaciobritoi, Istiodactylus sinensis, and Longchengpterus zhaoi. ...
... The assignment to the Ctenochasmatidae was based on the dorsoanteriorly compressed rostrum (although only the lower jaw is present) and the position of the teeth on the lateral border of the dentary. Although the authors are correct that several ctenochasmatids do have a dorsoventrally flattened anterior tip of the lower jaw (e.g., Gnathosaurus, Wellnhofer 1978), the number and overall morphology of the teeth are quite distinctive in this archaeopterodactyloid clade (e.g., Buisonjé 1981;Wang et al. 2007). Furthermore the mandibular symphysis of the Chinese taxon is quite short as compared to that of ctenochasmatids where the lower jaw is well known (e.g., Wellnhofer 1978). ...
A new pterosaur, Hongshanopterus lacustris gen. et sp. nov., from the Early Cretaceous Jiufotang Formation, western Liaoning, China is described. The specimen (IVPP V14582) consists of a skull preserved in palatal view and some iso-lated cervical vertebrae. Based on the labiolingually compressed teeth with a triangular crown Hongshanopterus lacus-tris is referred to the Istiodactylidae. It presents several plesiomorphic features such as the teeth not confined to the anterior third of the skull but extended more posteriorly, and is thus considered the most primitive member of this group. This new species also differs from other istiodactylids by having more teeth, some showing the crown distinctively directed posteriorly. Three other members of the Istiodactylidae are currently represented in the Jiufotang deposits: Nurhachius ignaciobritoi, Istiodactylus sinensis and Longchengpterus zhaoi. To those we add Liaoxipterus brachyo-gnathus, previously classified in the Ctenochasmatidae but that also has triangular labiolingually compressed teeth, and is a potential senior synonym of Lonchengpterus zhaoi. The palatal anatomy of Hongshanopterus lacustris also agrees with previous hypothesis that considers Istiodactylidae more closely related to the Anhangueridae than to Pteranodon (or Pteranodontidae).
... The sternum of Gegepterus is very poorly preserved and very little information is visible (Wang et al., 2007). It was described as being broad and thin, with the posterior edge convex in shape and at least three articulation points for sternal ribs (Wang et al., 2007). ...
... The sternum of Gegepterus is very poorly preserved and very little information is visible (Wang et al., 2007). It was described as being broad and thin, with the posterior edge convex in shape and at least three articulation points for sternal ribs (Wang et al., 2007). ...
... Ctenochasmatoidea is a group of pterosaurs within the suborder Pterodactyloidea and has been defined as the clade containing Cycnorhamphus suevicus, Pterodaustro guinazui, their most recent common ancestor, and all of its descendants [1]. At present, although there are nine genera of ctenochasmatoids reported from the Jehol Biota: Eosipterus [2], Beipiaopterus [3], Feilongus [4], Cathayopterus [5], Gegepterus [6][7], Elanodactylus [8][9], Pterofiltrus [10], Gladocephaloideus [11] and Moganopterus [12], they are known from either skulls or a relatively complete postcranial skeletons but not both, making comparisons difficult. A new specimen of a nearly complete juvenile assigned to Gladocephaloideus from the Lower Cretaceous Jiufotang Formation of Sihedang, Lingyuan of Liaoning Province (Fig 1) is therefore a significant addition as the most complete ctenocahsmatid yet recovered from this formation. ...
... The scores of Gladocephaloideus for phylogenetic analysis are based on the holotype (IG-CAGS 08-07) and an early juvenile individual (JPM 2014-004). The present analysis includes all nine genera of ctenochasmatoids reported from the Jehol Biota: Eosipterus [2], Beipiaopterus [3], Feilongus [4], Cathayopterus [5], Gegepterus [6], Elanodactylus [8], Pterofiltrus [10], Gladocephaloideus [11] and Moganopterus [12]. Although most of these generaare not represented by complete specimens, they still provide important information for analysis. ...
Although there are nine genera of ctenochasmatoids reported from the Jehol Biota, at present each is known from a specimen that has either a skull or a relatively complete postcranial skeleton. A nearly complete juvenile specimen of Gladocephaloideus from the Lower Cretaceous Jiufotang Formation of Sihedang, Lingyuan of Liaoning Province is the most complete ctenochasmatoid preserved to date with a skull and postcranial skeleton. Based on the holotype (IG-CAGS 08–07) and the nearly complete new specimen (JPM 2014–004), the diagnosis of Gladocephaloideus is amended: approximately 50 teeth in total with sharp tips; small nasoantorbital opening, occupying approximately 13% of total skull length; ratio of prenarial rostrum length to skull length approximately 0.63; deep groove along the mid-line of the mandibular symphysis; length to width ratio of the longest cervical vertebra = 4.1; ratio of femur length to tibia length = 0.61; tibia as long as the wing-phalange 1. Phylogenetic analysis recovers Gladocephaloideus within the clade Ctenochasmatidae. Gladocephaloideus has a closer relationship to the Chinese Pterofiltrus rather than to other ctenochasmatid pterosaurs. Microstructure of limb bones implies that JPM 2014–004 represents an early juvenile of Gladocephaloideus jingangshanensis, and that the type specimen is not a fully grown specimen either. We assume that the holotype may equate to the late juvenile or sub-adult developmental stage of Gladocephaloideus.
... Scleral ossicles are found across the family tree of Reptilia and more distantly related clades within Vertebrata, suggesting that the presence of scleral ossicles is plesiomorphic for all of Reptilia (Fig. 1). Palpebrals or supraorbitals are found in a variety of reptiles including microsaurs (Daly 1973), lizards (lacertids, scincoids, and anguimorphan lizards; Estes et al. 1988), pterosaurs (Coombs 1972;Wang et al. 2007), ornithischian dinosaurs (Coombs 1972;Maidment & Porro 2010) and crocodylomorphs (including Crocodylia) and other pseudosuchians (Walker 1961;Desojo & Baez 2007;Schoch 2007;Weinbaum 2011). Although all of these elements in the dorsal portion of the orbit have been referred to as either palpebrals or supraorbitals, the homology of these structures among extinct groups with the structures in extant reptile clades remains untested. ...
... The term ''palpebral'' has previously been applied to any bony element in the dorsal portion of the orbit in members of Reptilia including: squamates, crocodylians, pterosaurs, birds and ornithischian dinosaurs (Romer 1956;Coombs 1972;Lee 1997;Clark et al. 2000;Mayr 2005;Wang et al. 2007;Maidment & Porro 2010). The use of the same term to describe somewhat similar features across a broad range of taxa implies homology, but the homology of these features has never been explicitly tested. ...
Ossified skeletal elements within the orbit, such as scleral ossicles, palpebrals, supraorbitals and sesamoids, are widespread across Reptilia, including extant members of Crocodylia, Aves, Squamata and Chelonia. Extant crocodylians lack scleral ossicles, but have a unique palpebral that has recently been shown, through developmental studies, to be an osteoderm in the upper eyelid. Here, we examine the diversity and disparity of the crocodylian palpebral in extant members of Crocodylia and, through the fossil record, trace the origin and evolutionary history of the element throughout Pseudosuchia (all archosaurs more closely related to crocodylians than avians). We show that the crocodylian palpebral originated outside of Crocodylomorpha in early pseudosuchian groups (e.g. Aetosauria, Loricata) and that scleral ossicles are lost in nearly all groups of pseudosuchians, but appear in poposauroids, at least one early crocodylomorph, and some partially or fully marine Crocodyliformes (e.g. thalattosuchians). The morphology and number of palpebrals differs across Crocodyliformes; the presence of two palpebrals is plesiomorphic, but this is reduced to one by Crocodylia. We further recommend the restriction of the term palpebral to the structure in crocodylians and their homologues, but not to the structure in ornithischian dinosaurs.
... However, one significant difference of gnathosaurines from other ctenochasmatids is in their tooth robustness. Ctenochmastids are mostly filterfeeding, foraging in shallow waters with "needle-like" thin teeth, indicative of smaller prey items (Wang et al., 2007;Bestwick et al., 2018;Paul, 2022). The marked robustness of individual gnathosaur teeth suggests different feeding habits for their teeth being substantially larger and too widely-spaced for a true "filtration" functionality (Bestwick et al., 2018;Knoll, 2000), instead likely more associated to larger prey (e.g., piscivory). ...
An incomplete, yet remarkably-sized dentated rostrum and associated partial cervical vertebrae of a pterosaur (ML 2554) were recently discovered from the Late Jurassic (Late Kimmeridgian-Early Tithonian) Lourinhã Formation of Praia do Caniçal, of central west Portugal. This specimen exhibits features such as a spatulated anterior expansion of the rostrum, robust comb-like dentition, and pronounced rims of the tooth alveoli, indicating gnathosaurine affinities. Based on its further unique tooth and dentary morphology, a new genus and species, Lusognathus almadrava gen. et spec. nov., is proposed, making this the first named pterosaur species found within Portugal. The presence of this taxon adds yet another element to the fluvio-deltaic lagoonal environment that has been suggested as representative of the Lourinhã Formation in the Late Jurassic, further contributing to the diversity and distribution of gnathosaurines worldwide.
... Comparisons-The only archaeopterodactyloid clade that survived until the Early Cretaceous were ctenochasmatids (Andres et al., 2014), however, their teeth were highly elongated, distally recurved, and needle-like, which is distinct from the Kaniv specimens (Wang et al., 2007). Most azhdarchoids were edentulous with teeth being known only from dsungaripterids, which are short and relatively robust (Lü et al., 2009). ...
Early Cretaceous was a time of great diversity for pterosaurs with numerous taxa described from around the world. However, pterosaur record from Eastern Europe, especially in the Early Cretaceous, is scarce. In this study we describe several isolated pterosaur teeth from the Albian deposits of marine Burim formation in Kaniv Natural Reserve, Cherkasy region, Ukraine. Pterosaur fossils are uncommon in this fauna that is dominated by cartilaginous fish and actinopterygians. Pterosaur material is represented by at least two distinct morphotypes corresponding to Anhangueria and an indeterminate pterosaur taxon. Despite their fragmentary nature, these findings are significant as they represent the first described pterosaur fossils from Ukraine and the first described pterosaur teeth from the Early Cretaceous of Eastern Europe. Additionally, we discuss the potential for terrestrial vertebrate material being found in Mesozoic marine deposits which are abundant across Ukraine but remain poorly studied.
... Although this issue has been poorly studied in pterosaurs (Fastnacht, 2008 and references therein), previous studies reveal that a polyphyodont dental replacement was the norm in this clade (e.g. Dalla Vecchia, 2019;Fastnacht, 2008;Martill et al., 2023;Wang et al., 2007;Zhou et al., 2022). ...
Pterosaurs are an extinct group of Mesozoic flying reptiles, which exhibited high diversity with regard to their dentition. Although morphological features of pterosaur dentition have been described in detail in several contributions, the histology of tooth and tooth attachment tissues (i.e. periodontium) has been scarcely analysed to date for this clade. Here we describe and interpret the microstructure of the tooth and periodontium attachment tissues of Pterodaustro guinazui, a filter-feeding pterodactyloid pterosaur from the Lower Cretaceous of Argentina. The histological analysis of the lower jaw and its filamentous teeth verifies that the geometry of the implantation corresponds to an aulacodont condition (i.e. teeth are set in a groove with no interdental separation). This pattern departs from that recorded in other archosaurs, being possibly also present in other, non-closely related, pterosaurs. Regarding tooth attachment, in contrast to other pterosaurs, there is no direct evidence for gomphosis in Pterodaustro (i.e. the absence of cementum, mineralized periodontal ligamentum and alveolar bone). Nevertheless, the current evidence for ankylosis is still not conclusive. Contrary to that reported for other archosaurs, replacement teeth are absent in Pterodaustro, which is interpreted as evidence for monophyodonty or diphyodonty in this taxon. Most of the microstructural features are possibly related to the complex filter-feeding apparatus of Pterodaustro and does not appear to represent the general pattern of pterosaurs.
... The Ctenochamatidae Nopcsa, 1928 were a diverse and widely distributed clade of pterodactyloid pterosaurs, first recorded in Europe from the Late Jurassic (Tithonian) Solnhofen Limestone of Bavaria, Germany (Meyer 1833(Meyer , 1852(Meyer , 1854 and in the Portlandian of France (Taquet 1972 (Andres and Ji 2008;Bonaparte 1970;Buffetaut and Jeffrey 2012;Dong 1982;Harris and Carpenter 1996;Howse and Milner 1995;Ji and Ji 1997;Lü et al. 2012;Martill et al. 2006;Perea et al. 2018;Sotto et al. 2021;Wang et al. 2006). Ctenochasmatids are typified by large numbers of elongate slender, slightly curved or even recurved interlocking teeth primarily involved in filter-feeding. ...
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.
... Zhou et al. 2020). Of these, cranial morphology is known in eight genera: Cathayopterus, Feilongus, Forfexopterus, Gegepterus, Gladocephaloideus, Moganopterus, Pangupterus and Pterofiltrus (Wang et al. 2005(Wang et al. , 2007Wang and Zhou 2006;Andres and Ji 2008;Jiang and Wang 2011a;Lü et al. 2012aLü et al. , b, 2016Jiang et al. 2016). Their teeth appear to vary in morphology, quantity and density (e.g. ...
Ctenochasmatid pterosaurs flourished and diversified in the Early Cretaceous Jehol Biota. Here, a partial mandible of Forfexopterus is described based on a three-dimensional reconstruction using high-resolution X-ray Computed Tomography (CT) data. The first nine pairs of functional teeth of the rostral dentition revealed along with their replacements. The functional teeth are evenly arranged with a tooth density of 2.2 teeth/cm. The tooth crown is distinctly reduced from its base to the tip, and framed by two weak ridges, possibly as a pair of vestigial carinae. The replacement teeth are sharp and pointed, and have erupted slightly against the medial surface of the functional teeth. Surprisingly, tooth wear is observed in this specimen, the first record of tooth-tooth occlusion in ctenochasmatids. The wear facets exhibit high-angled lingual and lower-angled labial facets, implying a tooth-tooth occlusion in pterosaur clade. This discovery indicates that the Jehol ctenochasmatids possibly employed a more active feeding strategy than other filter-feeding pterosaurs (e.g. Ctenochasma , Pterodaustro , Gnathosaurus ).
Supplementary material at https://doi.org/10.6084/m9.figshare.c.5722060
... ventricosa and Sphaerium (Sphaerium) anderssoni [¼S. jeholense], fish including Lycoptera muroii, amphibians, reptiles including feathered dinosaurs, birds and mammals (e.g., Gu et al., 1976;SIGMR, 1980;Gu, 1982;Dong, 1985;Yu et al., 1987;Liu et al., 1990;Chen and Jin, 1999;Pan and Zhu, 1999;Sun et al., 2001;Chang et al., 2001Chang et al., , 2003Ji et al., 2004;Sha et al., 2006Sha et al., , 2012Jiang et al., 2007;Li and Batten, 2007;Liu et al., 2007;Lü et al., 2007;Zhang, 2007;Zhang et al., 2007;Sha, 2007a;Wang et al., 2007a;Pan et al., 2013;Li, 2017). ...
The present paper is the second article in a series of publications dedicated to the upper Mesozoic stratigraphy of Sikhote-Alin (Russian Far East) and northeastern China. The Barremian – Albian stratigraphy of Sikhote-Alin and northeastern China is reviewed and a correlation scheme between these regions is proposed. Barremian – Albian rocks in Sikhote-Alin are mainly represented by marine deposits. Non-marine deposits occur in the south of Sikhote-Alin in the Partizansk and Razdolny basins. In northeastern China, in contrast, the Barremian – Albian rocks are mainly non-marine often intercalated with volcanic rocks. Non-marine deposits alternating with marine ones occur in northeastern Heilongjiang near the border with Russia. They fill a system of sedimentary basins restricted to the Dunhua-Mishan Fault Zone and linked in the east with the Alchan Basin of Sikhote-Alin. The deposits of these basins, represented by the Jixi, Longzhaogou, Dajiashan and Huashan groups, and the Assikaevka and Alchan formations, are of high importance for non-marine and marine correlation because they contain non-marine fauna and flora assemblages together with marine molluscs. The range of the Jixi and Longzhaogou groups is clarified based on the correlation with the Assikaevka Formation containing marine index fossils and is considered here as Barremian (possibly extending to Hauterivian) – middle Albian. The Jixi Group yielding elements of the Jehol Biota corresponds to the Jehol Group, and, therefore, the range of the Jehol Group is also considered as Barremian – middle Albian.
... Under the fossa, the coracoid shaft extends medially. A ventral crest, referred to as the coracoid flange by Jiang et al. (2016), is weakly developed along the proximal half of the coracoid shaft, as in the type specimen of F. jeholensis (HM V20) and other ctenochasmatids (e.g., Beipiaopterus, Gegepterus, and Elanodactylus;Lü, 2003;Wang et al., 2007;Andres and Ji, 2008;Zhou, 2010). A similar structure is also known but highly varied in azhdarchoids (e.g., Liu et al., 2015). ...
In the Jehol Biota, the filter-feeding ctenochas-matid 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.
... Circles represent genera (Andres and Ji, 2008;Kellner, 1985, 1997;Dong and Lü, 2005;Frey and Martill, 1994;Howse et al., 2001;Ji and Ji, 1997;Jiang and Wang, 2011;Kellner, 1984;Kellner and Tomida, 2000;Lawson, 1975;Lü, 2003;Lü et al., 2012aLü et al., , 2012bLü et al., , 2017Lü and Ji, 2005;Lü and Qiang, 2005;Lü and Zhang, 2005;Marsh, 1876;Rodrigues et al., 2015;Steel et al., 2005;Sweetman and Martill, 2010;Unwin, 2001;Veldmeijer et al., 2005;Wang et al., 2005Wang et al., , 2007Wang et al., , 2012Wang et al., , 2014Wang and Lü, 2001;Wang and Zhou, 2006;Wellnhofer, 1987). ...
A new genus and species of edentulous pterodactyloid pterosaur with a distinctive partial rostrum from the mid-Cretaceous (?Albian/Cenomanian) Kem Kem beds of southeast Morocco is described. The taxon is assigned to Chaoyangopteridae based upon its edentulous jaws, elongate rostrum and slightly concave dorsal outline. The rostral cross-section is rounded dorsally and concave on the occlusal surface. The lateral margins are gently convex dorsally becoming slightly wider toward the occlusal border, and a row of small lateral foramina parallel to the dorsal margin determines it as a taxon distinct from other chaoyangopterids. Apatorhamphus gyrostega gen et sp. nov. is a pterosaur of medium to large size (wingspan likely somewhere between ~3 m and ~7 m). This new species brings the number of named Kem Kem azhdarchoids to three, and the number of named Kem Kem pterosaurs to five, indicating a high pterosaur diversity for the Kem Kem beds.
... The ceratobranchial/skull length ratios have a decreasing trend from long-tailed pterosaurs to short-tailed Pterodactyloidea ( Fig. 2; Table 1). In Kunpengopterus (Fig. 3C), Paiten pro-pterodactyloid, and Pterodactylus (Fig. 3D), the ceratobranchials shortens to approximately 30% of the skull length (Cheng et al., 2017;Tischlinger & Frey, 2013;Bennett, 2013;Wellnhofer, 1970), while the ratios dropped to less than 20% in the gallodactylids Gladocephaloideus (Lü et al., 2012) and Feilongus (Fig. 3E) (Wang et al., 2005), as well as in ctenochasmatid pterosaurs, such as Gegepterus (Fig. 3F) (Wang et al., 2007;Jiang & Wang, 2011a), andPterofiltrus (Jiang & Wang, 2011b). ...
The pterosaur is the first known vertebrate clade to achieve powered flight. Its hyoid apparatus shows a simplification similar to that of birds, although samples of the apparatus are rare, limiting the ability to make an accurate determination. In this study we reveal a new pterosaur specimen, including the first definite basihyal. Through the comparison of pterosaur hyoids, a trend has been discovered for the shortened hyoid relative to the length of the skull, indicating a diminished role of lingual retraction during the evolution of the pterosaur. The new material, possibly from a gallodactylid Gladocephaloideus , represents one of the least effective lingual retractions in all pterosaurs. Based on the structure of an elongated ceratobranchial and retroarticular process on mandibles, the function of the Y-shaped istiodactylid tongue bone is similar to those of scavenger crows rather than chameleons, which is consistent with the interpretation of the scavenging behavior of this taxon. More fossil samples are needed for further study on the function of other pterosaur hyoids.
... They are neither completely flattened as occurs frequently in some fossil Lagerstätten such as the Jehol Group of China (e.g. Chang et al. 2003;Wang et al. 2007), nor do they show the excellent three dimensional preservation with little or no deformation seen in material from the Santana Formation (e.g. Fara et al. 2005). ...
We redescribe the holotype of the saurischian dinosaur Staurikosaurus pricei Colbert, 1970 from Late Triassic Santa Maria Formation (southern Brazil), following additional preparation that revealed new anatomical features. A revised diagnosis is proposed and the published synapomorphies for Dinosauria and less inclusive clades (e.g. Saurischia) are evaluated for this species. Some characters previously identified as present in the holotype, including the intramandibular joint, hyposphene-hypantrum articulations in dorsal vertebrae, and a cranial trochanter and trochanteric shelf on the femur, cannot be confirmed due to poor preservation or are absent in the available material. In addition, postcranial characters support a close relationship between S. pricei and Herrerasaurus ischigualastensis Reig, 1963 (Late Triassic, Argentina), forming the clade Herrerasauridae. Several pelvic and vertebral characters support the placement of S. pricei as a saurischian dinosaur. Within Saurischia, characters observed in the holotype, including the anatomy of the dentition and caudal vertebrae, support theropod affinities. However, the absence of some characters observed in the clades Theropoda and Sauropodomorpha suggests that S. pricei is not a member of Eusaurischia. Most morphological characters discussed in previous phylogenetic studies cannot be assessed for S. pricei because of the incompleteness of the holotype and only known specimen. The phylogenetic position of S. pricei is constrained by that of its sister taxon H. ischigualastensis, which is known from much more complete material.
... Furthermore, the referral of Mythunga to the Archaeopterodactyloidea was refuted by Kellner et al. (2010), on the basis that the dentition appears inconsistent with that of any archaeopterodactyloid (e.g. Wang et al., 2005Wang et al., , 2007 and that the estimated wingspan of 4.7 m (Molnar and Thulborn, 2007) was greater than that of any reported archaeopterodactyloid (Wang et al., 2005). Kellner et al. (2010) regarded Mythunga as a potential anhanguerid; however, these authors noted that several significant anhanguerid cranial synapomorphies could not be observed in QM F18896, even though its size and dentition were consistent with other anhanguerids. ...
Mythunga camara, the most complete pterosaur described from Australia, derives from the Lower Cretaceous (Albian) Toolebuc Formation of central Queensland, Australia. Although it was originally described as an archaeopterodactyloid, more recently Mythunga has been designated as an indeterminate anhanguerid or ornithocheiroid. The holotype specimen is a partial skull, comprising a fragment of the premaxilla, incomplete maxillae and dentaries, and an isolated cranial element preserved in matrix within the nasoantorbital fenestra. Reassessment of the holotype specimen has revealed several new features, which enable a re-evaluation of the phylogenetic position of this taxon. Primary among these observations is that the anteriormost preserved teeth are, in fact, the root of a maxillary tooth and its replacement, rather than a pair of contralateral teeth; thus, they do not represent the anteriormost tooth pair as previously proposed. Redescription of the holotype specimen has also resulted in the identification of several previously unrecognised features, including several nutrient foramina on the maxilla and mandible and shallow channels on the maxilla. Furthermore, the bone lodged within the nasoantorbital fenestra is identified herein as the right splenial. Following the redescription and reinterpretation of the holotype specimen, the phylogenetic position of Mythunga camara was assessed. Although this analysis placed Mythunga within the Anhangueria, most of this clade was reduced to a polytomy; only the clades representing Anhanguera and Boreopterinae + Guidraco were resolved. The classification of Mythunga within Anhangueria indicates that this clade was widespread, and perhaps achieved a global distribution by the late Early Cretaceous.
... These flying reptiles developed a comparatively fragile skeleton that resulted in a generally limited preservation potential (e.g., Wellnhofer, 1991;Kellner, 1994). As a consequence, except for three so far monotaxic bonebeds (Chiappe et al., 2000;Wang et al., 2014a;Manzig et al., 2014), most species are represented only by one or two specimens (e.g., Wang et al., 2007;Wang et al., 2014b;Jiang & Wang, 2011;. ...
The Wukongopteridae compose a non-pterodactyloid clade of pterosaurs that are the most abundant flying reptiles in the deposits of the Middle-Late Jurassic Yanliao Biota. Until now, five species of three genera and two additional unnamed specimens have been described. Here we report on a new material, IVPP V 23674, that can be referred to the wukongopterid Kunpengopterus sinensis due to several features such as a comparably short nasoantorbital fenestra, the dorsally rising posterodorsal margin of the ischium, and the very short first pedal phalanx of digit V relative to metatarsal IV. IVPP V 23674 provides the first view of a wukongopterid palate, which differs from all other pterosaurs by having a very large postpalatine fenestra and laterally compressed choanae, indicating that the evolution of the pterosaur palate was more complex than previously thought. Sesamoid bones at the dorsal side of manual unguals are present and are reported for the first time in a wukongopterid suggesting an arboreal life-style for these pterosaurs.
... Ctenochasmatidae is the only clade of archaeopterodactyloids to have survived into the Cretaceous. The dentition of ctenochasmatids consists of a large number of recurved, elongated, needle-like teeth in both the upper and lower jaws (e.g., Huanhepterus, Gegepterus, Moganopterus;Dong, 1982;Wang et al., 2007;Lü et al., 2012). This dental morphology is taken to an extreme by Pterodaustro in which approximately 1,000 bristle-like teeth lined the jaws (Chiappe & Chinsamy, 1996). ...
The fossil record of Australian pterosaurs is sparse, consisting of only a small number of isolated and fragmentary remains from the Cretaceous of Queensland, Western Australia and Victoria. Here, we describe two isolated pterosaur teeth from the Lower Cretaceous (middle Albian) Griman Creek Formation at Lightning Ridge (New South Wales) and identify them as indeterminate members of the pterodactyloid clade Anhangueria. This represents the first formal description of pterosaur material from New South Wales. The presence of one or more anhanguerian pterosaurs at Lightning Ridge correlates with the presence of ‘ornithocheirid’ and Anhanguera-like pterosaurs from the contemporaneous Toolebuc Formation of central Queensland and the global distribution attained by ornithocheiroids during the Early Cretaceous. The morphology of the teeth and their presence in the estuarine- and lacustrine-influenced Griman Creek Formation is likely indicative of similar life habits of the tooth bearer to other members of
... The midline sagittal crest on the parietals has not been reported in non-pterodactyloids and is most similar to the blunt sagittal crest coded in the anhanguerids (Kellner, 2003). A ridge at the contact between the frontals and the parietals has been reported in the pterodactyloid Gegepterus changi (Wang et al., 2007). Mandible—The right and left mandibular rami are present though severely cracked and distorted (Fig. 2). ...
... They are neither completely flattened as occurs frequently in some fossil Lagerstätten such as the Jehol Group of China (e.g. Chang et al. 2003;Wang et al. 2007), nor do they show the excellent three dimensional preservation with little or no deformation seen in material from the Santana Formation (e.g. Fara et al. 2005). ...
We redescribe the holotype of the saurischian dinosaur Staurikosaurus pricei Colbert, 1970 from Late Triassic Santa Maria Formation (southern Brazil), following additional preparation that revealed new anatomical features. A revised diagnosis is proposed and the published synapomorphies for Dinosauria and less inclusive clades (e.g. Saurischia) are evaluated for this species. Some characters previously identified as present in the holotype, including the intramandibular joint, hyposphene-hypantrum articulations in dorsal vertebrae, and a cranial trochanter and trochanteric shelf on the femur, cannot be confirmed due to poor preservation or are absent in the available material. In addition, postcranial characters support a close relationship between S. pricei and Herrerasaurus ischigualastensis Reig, 1963 (Late Triassic, Argentina), forming the clade Herrerasauridae. Several pelvic and vertebral characters support the placement of S. pricei as a saurischian dinosaur. Within Saurischia, characters observed in the holotype, including the anatomy of the dentition and caudal vertebrae, support theropod affinities. However, the absence of some characters observed in the clades Theropoda and Sauropodomorpha suggests that S. pricei is not a member of Eusaurischia. Most morphological characters discussed in previous phylogenetic studies cannot be assessed for S. pricei because of the incompleteness of the holotype and only known specimen. The phylogenetic position of S. pricei is constrained by that of its sister taxon H. ischigualastensis, which is known from much more complete material.
... Nevertheless, it is also clear that Elanodactylus presents postexapophyses, a feature that is not common to more primitively placed pterodactyloids. Postexapophyses have been previously recorded in the ctenochasmatid archaeopterodactyloid Gegepterus (also from the Yixian Formation, Wang et al. 2007). Other archaeopterodactyloids, including the ctenochasmatid Ctenochasma, however, lack postexapophyses. ...
The pterosaur fossil record from Africa is exceedingly scarce and one of the least known for any continental land mass. The specimens here described are housed at the Naturkundemuseum of the Humboldt University and consist of two cervical vertebrae, a coracoid and a wing metacarpal recovered from the Upper Jurassic Tendaguru Formation, Tanzania. Due to the general morphology and the absence of a lateral pneumatic foramen in both vertebrae, as well as the presence of a longitudinal depression, not previously reported in pterosaurs, we consider these specimens as representatives of a new species of Azhdarchidae. Moreover, because the coracoid, which bears three well-developed pneumatic foramina, has a well-excavated depression that is medially positioned at the posterior face of the acrocoracoid process, we regard this as a new basal pterodactyloid species. The wing metacarpal is greatly elongated and clearly belongs to Pterodactyloidea. Its elongation and slender aspect, as well as the sub-triangular shape of its proximal articular end, likely place it within the Tapejaroidea. The material here described shows the potential of these deposits to provide more informative pterosaur material and provisionally extends the oldest record of azhdarchids to the Kimmeridgian–Tithonian of Africa.
Background:
Although various angiosperms (including their flowers) have been reported from the Yixian Formation (Lower Cretaceous) of China, which is famous worldwide for its fossils of early angiosperms, no flower bud has hitherto been seen in the Early Cretaceous. Such a lack of examples hinders our understanding of the evolution of flowers.
Methods:
The specimen studied in the present paper was collected from an outcrop of the Yixian Formation (the Barremian-Aptian, Lower Cretaceous) of Dawangzhangzi in Lingyuan, Liaoning, China. The specimen was photographed using a Nikon D200 digital camera, its details were observed and photographed using a Nikon SMZ1500 stereomicroscope, and some of its details were observed using a Leo 1530 VP SEM.
Results:
We report a fossilized flower bud, Archaebuda lingyuanensis gen. et sp. nov, from the Yixian Formation of China. The debut of Archaebuda in the Yixian Formation provides first-hand material for debate on the early evolution of angiosperm flowers and underscores the great diversity of angiosperms in the Yixian Formation.
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.
Morphology forms the most fundamental level of data in vertebrate palaeontology because it is through interpretations of morphology that taxa are identified, creating the basis for broad evolutionary and palaeobiological hypotheses. Assessing maturity is one of the most basic aspects of morphological interpretation and provides the means to study the evolution of ontogenetic changes, population structure and palaeoecology, life‐history strategies, and heterochrony along evolutionary lineages that would otherwise be lost to time. Saurian reptiles (the least‐inclusive clade containing Lepidosauria and Archosauria) have remained an incredibly diverse, numerous, and disparate clade through their ~260‐million‐year history. Because of the great disparity in this group, assessing maturity of saurian reptiles is difficult, fraught with methodological and terminological ambiguity. We compiled a novel database of literature, assembling >900 individual instances of saurian maturity assessment, to examine critically how saurian maturity has been diagnosed. We review the often inexact and inconsistent terminology used in saurian maturity assessment (e.g. ‘juvenile’, ‘mature’) and provide routes for better clarity and cross‐study coherence. We describe the various methods that have been used to assess maturity in every major saurian group, integrating data from both extant and extinct taxa to give a full account of the current state of the field and providing method‐specific pitfalls, best practices, and fruitful directions for future research. We recommend that a new standard subsection, ‘Ontogenetic Assessment’, be added to the Systematic Palaeontology portions of descriptive studies to provide explicit ontogenetic diagnoses with clear criteria. Because the utility of different ontogenetic criteria is highly subclade dependent among saurians, even for widely used methods (e.g. neurocentral suture fusion), we recommend that phylogenetic context, preferably in the form of a phylogenetic bracket, be used to justify the use of a maturity assessment method. Different methods should be used in conjunction as independent lines of evidence when assessing maturity, instead of an ontogenetic diagnosis resting entirely on a single criterion, which is common in the literature. Critically, there is a need for data from extant taxa with well‐represented growth series to be integrated with the fossil record to ground maturity assessments of extinct taxa in well‐constrained, empirically tested methods.
Archosaurs is the clade composed by birds (Aves) and crocodiles, alligators, and the gharial (Crocodylia). This relatedness is not obvious and for a long time was not taken into account, as birds were seen as a group separate even from the rest of reptiles. Both avians and crocodylians are morphologically very distinct and in many aspects different from each other and from the ancestral forms within Archosauria. The skulls of birds are composed of thin and light bones, many fused to each other, and others articulating in mobile joints allowing the beak to move and bend with respect to the rest of the skull. In crocodylians the skulls are massive and heavy, a solid akinetic structure built to crush prey. The accompanying muscle system, attaching onto and responsible for the movement of the head, jaws, eyes, or tongue, is equally distinct. As a result of the striking differences and the relatively recent realization of crocodylians and avians being closely related, the comparison of their anatomy has never been very straightforward. This chapter’s goal is to provide a review of archosaur anatomy and to give at least some sense of the similarities and differences between archosaur musculature.
The Tacuarembó Formation contains a faunal assemblage with some taxa clearly indicative of a Late Jurassic-Early Cretaceous age. In this context, the first remains of Uruguayan pterosaurs are described. These correspond to a dorsoventrally compressed and narrow fragment of a rostrum widening anteriorly, with alveoli and a very fragmentary dentition including a tooth base. The orientation of the alveoli and preserved tooth base allows the assumption that the teeth were projected laterally and forward from the dental borders. The deep interdental concavities make up a wavy contour of the lateral margins of the rostrum. Both morphology and size correspond to that observed in the ctenochasmatid gnathosaurines. The Uruguayan pterosaur remains represent the oldest ctenochasmatid found in South America and suggest an age of the sediments no older than Late Jurassic, which was already concluded from other fossils, as Priohybodus arambourgui d'Erasmo, 1960, within others.
Most of the fossil materials documented in this book are from the Jurassic and Cretaceous of northeastern China. In this chapter, the author describes the geological and palaeobiological backgrounds in this region, which is very helpful for a complete understanding of the plant fossils to be documented in the later chapters. The Yixian Formation and Jiulongshan Formation are by far the most productive strata for early angiosperms, and, therefore, they are dealt with some details in this chapter. The geological background and age of the formations are briefly summarized. Species list and assemblages in various faunas and floras are given. For those not interested in details of the fossil floras and faunas, please feel free to skip certain sections in this chapter.
Pangupterus liui gen. et sp. nov. from the Jiufotang Formation of Sihedang, Lingyuan City, Liaoning Province is erected based on a nearly complete lower jaw. It is characterized by having a total of 36 slender curved teeth with sharp tips, forming a distinct fish-grabbing mechanism; the teeth are well-spaced and are circular in section; the length ratio of the mandibular symphysis to the whole jaw is 20%; and the ratio of the tooth root width to tooth length is 12%. Toothed pterosaurs make up about 56.3% of the pterosaur assemblage from the Jiufotang Formation, which indicates that toothed forms played a key role in the ecosystem.
The following are the 123 morphological characters and their coding used in the cladistic analysis in Chap. 5. Morphological characters No. 1–4 are new, No. 5–15 are the characters No. 2–8, 10–12 and 14 from the dataset of Sun et al. (2002), No. 16–123 are the characters No. 1–108 from the dataset of Doyle and Endress (2000). For detailed discussion, see the original references.
Agaricus blazei Murrill fruit polysaccharides was extracted by microwave technology after supercritical CO2 fluid extracting. Agaricus blazei Murill oligopeptide were manufactured through proteolysis of two kind protease after degreasant and polysaccharide-free, and the antioxidation activity of oligopeptide was preliminary studied. The results show that the optimum hydrolyzing conditions of Alcalase 2.4L are pH=8.5, temperature 55 °C, concentration of substrate is 5%, time is 2 h, the amount of enzyme is 1.5%, the yield of peptide is 74.7%.The optimum hydrolyzing conditions of Flavourzyme are pH=7.0, temperatue 50 °C, time is 1.5 h, enzyme concentration 4%, the final peptide yield reached 80.6%. Agaricus blazei Murrill oligopeptide is rich in Pro, Lys, Phe, the content of essential amino acid (EAA) is 50.91%, the molecular weight below 5600. The anti oxidation activity of Agaricus blazei Murrill oligopeptide has obviously activity of antixidation, the suppression rate is 35.6%.
Two new multi-copper-containing polyoxotungstates [Cu(en)2(H2O)2] [Cu(en)2]4 [Cu(en)2(H2O)] [Cu4(H2O)2 (SiW9O34)2] · 7H2O(1) and [Cu(en)2(H2O)]2 [Cu(en)2]4 [CuSiW11O39]2 · 7H2O(2) were hydrothermally synthesized. The diffraction analysis reveals that compound 1 represents the organic-inorganic hybrid based on the sandwich-type polyoxometalates linked by transition-metal coordination cations. The framework of 2 has a two-dimensional net-texture structure with vacancies in it, and the 2D layers are arranged in a parallel-staggering fashion to form a 3D supermolecules framework. It represents a 3D organic-inorganic hybrid based on the bimolecular Keggin polyoxometalates.
Pterosaurs have been found in eight provinces in China, and their geological ages are from the Middle Jurassic to the Late Cretaceous. We have analyzed the U-Pb zircon ages of two pterosaur localities, Linglongta in Liaoning and Tangshang Formation in Zhejiang, whose ages were disputable. The youngest age of detrital zircons is 150 Ma, which suggested that the age of the Linglongta Pterosaur Fauna was younger than 150 Ma. Two different ages of tuffs from Tangshang Formation in different basins in Zhejiang were obtained: one from Tiantai basin, underlying the dinosaur-egg bearing strata, is 113 Ma and one from Shangpan locality of Linhai is 90 Ma; the pterosaurs were found in the latter basin. These results suggested that Zhejiangopterus was in the Late Cretaceous, and the Tangshang Formation in Tiantai and Xiaoxiong basins were deposited in different times. On the basis of these new ages of two localities, we preliminarily summarized the geochronology and stratigraphic sequence of pterosaur fossil-bearing beds in China, and the pterosaurs from the Early Cretaceous were in the main position.
The feeding behavior of pterosaurs was varied in different groups. Judging by the tooth morphologies and fossilized stomach contents of pterosaurs, the feeding habits included fish-eating, insect-eating, filtering small aquatic organisms, eating shelled crabs and snails, and fruit-eating. Because of the need for survival, they occupied different ecological niches, which determined their different food sources. Herein described is an almost complete, well-preserved hyoid apparatus of Liaoxipterus brachyognathus in comparison with the hyoid apparatus of the modern lizard Chameleon. The long processus lingualis (processus entoglossus) is similar to that of the modern lizard Chameleon, which captures prey by tongue, implying that Liaoxipterus might share a similar lingual feeding behavior. This phenomenon, plus its special tooth morphology, further suggests that it was an insect-eating rather than fish-eating pterosaur.
Pterosaurs first appeared in the Late Triassic and persisted until the terminal Cretaceous: they achieved a global distribution during the Mesozoic. Here, we attempt to provide the first comprehensive summary of pterosaur distribution through time and space, including information on the taxonomie composition of pterosaur faunas and the lithostratigraphic units in which they occur. We hope that this compilation will be used as a primary research tool, permitting more detailed and rigorous analyses of pterosaur diversity and palaeobiogeography than have been possible to date.
Based on a new nearly naturally preserved skull and four cervical vertebrae of the pterosaur Feilongus sp. from the lower Cretaceous Jiufotang Formation of Beipiao, western Liaoning province, northeastern China, the diagnosis of Feilongus is amended. The revised diagnosis notes long, curved, needle-shaped teeth that are confined to the jaw far anterior to the nasoantorbital fenestra; posterior teeth that are slightly smaller than the anterior teeth; cervical vertebrae elongated with a ratio of length to width greater than 5; tooth number of about 78; and two cranial sagittal crests.
: A new pterosaur Moganopterus zhuiana gen. et sp. nov. is erected based on a complete skull with lower jaws and anterior cervical vertebrae. It is characterized by much elongated upper and lower jaws with at least 62 total, long, curved teeth with sharp tips, a well developed parietal crest extending posterodorsally, forming an angle of 15 degrees with the ventral margin of the skull, the ratio of length to width of cervical vertebrae greater than 5:1. The skull length is 750 mm, and it is the largest toothed pterosaur found so far in the world. Based on this new pterosaur, the Boreopteridae can be divided into two subgroups: Boreopterinae sub-fam. nov. and Moganopterinae sub-fam. nov., which is also confirmed by the phylogenetic analysis.
A new partial specimen of Zhenyuanopterus from the Lower Cretaceous Yixian Formation of Beipiao city, Liaoning Province is described. This specimen is slightly larger than half the size of the holotype. Although it is not complete, it provides new information on Zhenyuanopterus both in taxonomy and ontogeny: the total number of the caudal vertebrae is 15; the forelimb is more robust than the hindlimb; the growth rate of the humerus and femur is constant, and their ratio is about 1. Compared with the holotype, the scapula and coracoid grow faster than the humerus and the femur. The scapula and coracoid may slow their growth rate after a certain ontogenetic stage. The pectoral girdle, robust forelimb and weak hindlimb of the new material (XHPM1088) together with data from the holotype of Zhenyuanopterus indicate that this taxon spent less time on land than in the sky or other ecological niches such as forests and cliffs.
A reassessment of the systematic relationships of pterosaurs from the Lower Cretaceous Yixian Formation of Liaoning Province, China, shows that Dendrorhynchoides should be reassigned to the Anurognathidae (“Rhamphorhynchoidea”) and that Eosipterus possibly belongs within Ctenochasmatidae (Pterodactyloidea). These pterosaurs formed an integral part of a diverse community that inhabited lowland terrestrial environments in the region of northeast China in the Early Cretaceous. A new compilation of data for the Lower Cretaceous hints at a broad differentiation between pterosaurs that lived in continental habitats (anurognathids, ctenochasmatoids, dsungaripteroids) and those that frequented marine environments (ornithocheiroids). Moreover, there is evidence of further differentiation within continental habitats, between pterosaurs living in lowland and coastal regions (anurognathids. ctenochasmatoids) and those living in more inland environments (dsungaripteroids). The temporal and geographical range extensions for high rank taxa that are implied by the Yixian pterosaurs further emphasise the incompleteness and unevenness of the pterosaur fossil record and its unreliability for biostratigraphic zonation.
In this article we describe a new and exceptionally well-preserved pterodactyloid pterosaur,Sinopterus dongi gen. et sp. nov. from the Jiufotang Formation in western Liaoning Province of northeast China. The new species is referred
to the family Tapejaridae, representing its first record outside Brazil. It also represents the earliest occurrence as well
as the most complete skeleton of the family. Some revisions are made about the family according to the morphological observations
of the postcranial bones ofSinopterus. Two pterosaur assemblages appear to have existed in the Jehol Group, represented by the lower Yixian Formation and upper
Jiufotang Formation, respectively. The lower pterosaur assemblage shows some resemblance to that of the Late Jurassic in Solnhofen
(Tithonian) by sharing members of the Pterodactylidae and Anurognathidae. The upper one shows more resemblance to that of
the Early Cretaceous Santana Formation (Aptian/Albian) by comprising only pterodactyloids such as the Tapejaridae. The age
of the Yixian Formation is younger than that of the Solnhofen lithographic limestone, and the age of the Jiufotang Formation
(Aptian) is slightly older than the Santana Formation.
KeywordsPterodactyloidea-Tapejaridae-
Sinopterus
-Jiufotang Formation-Jehol Group-biostratigraphy-Chaoyang-Liaoning
We report a new and nearly completely articulated rhamphorhynchoid pterosaur, Jeholopterus ningchengensis gen. et sp. nov., with excellently preserved fibres in the wing membrane and “hairs” in the neck, body and tail regions.
Many of its characteristics such as a short neck, short metacarpals and distinctively long fifth pedal digit are characteristic
of rhamphorhynchoids. The new species can be further referred to the ‘strange’ short-tailed rhamphorhynchoid family Anurognathidae.
It is much more complete than the other known members of the family, namely, Anurognathus from Solnhofen, Germany, Batrachognathus from Karatau, Kazakhstan, and Dendrorhynchoides from Beipiao, Liaoning Province, China. The new pterosaur also shows that the wing membrane is attached to the ankle of the
hind limb. The pedal digits are webbed. Furthermore, the “hair” of Jeholopterus bears some resemblance to the hair-like integumental structures of the feathered dinosaur Sinosauropteryx although there is yet no direct evidence to argue for or against their homology.
A well-preserved pterosaur with nearly complete skull is described from the Lower Cretaceous Yixian Formation at Sihetun in
western Liaoning. It is characterized by a low and long crestless skull, slender and pointed teeth, long metacarpal, nearly
equal length of metatarsals I–III and short pedal digit V. It is referred to a new genus and species of the family Pterodactylidae:Haopterus gracilis gen. et sp. nov. This is the first pterosaur with a nearly complete skull from the Jehol Biota; it also represents the first
non-controversial fossil record of Pterodactylidae in Asia.Haopterus is more derived thanPterodactylus from the Late Jurassic Solnhofen in Germany. This discovery extends the distribution of the family Pterodactylidae from Europe
and Africa to Asia and its latest occurrence from the Late Jurassic to the Early Cretaceous. The discovery ofHaopterus gracilis provides further evidence for the study of the origin and radiation of the Jehol Biota; it also sheds new light on the evolution
and distribution of pterosaurs in the late Mesozoic.
A Ctenochasma specimen from the latest Jurassic of eastern France is described in detail and referred to Ctenochasma sp. The preserved braincase of this specimen has a bird-like lateral position of the optic lobes, with proportionally a smaller size than in birds, the bones surrounding it being thick and hollow.An original biometric analysis, based on skull length and tooth number, has been performed using a selection of Late Jurassic Pterodactyloidea of Europe. This study suggests that Ctenochasma gracile and Ctenochasma porocristata are senior synonyms of Pterodactylus elegans and Pterodactylus antiquus of Pterodactylus kochi. It also reveals that Pterodactylus elegans may be transferred to Ctenochasma. These results obtained with biometric analyses are confirmed by morphological observations. This study could not determine if Pterodactylus micronyx is a juvenile of C. roemeri, the Ctenochasma of Saint Dizier or Gnathosaurus subulatus. Because this species is only composed of juveniles, more data are needed to determine its adult morphology. The genus Ctenochasma is thus represented by three species, C elegans, C. roemeri and C. sp., and Pterodactylus by two, P. antiquus and P. longicollum, all from the Late Jurassic of Germany and France. This study points out a biological anomaly: all the teeth are not present in a hatching pterosaur, but their number increase progressively during growth, with new teeth erupting from the front of the jaws. This phenomenon is particularly spectacular in Ctenochasma elegans, where the tooth number increases progressively from 60 to more than 400 teeth during growth.
The discovery of a previously undescribed pterosaur, Thalassodromeus sethi, yields information on the function of cranial crests and the feeding strategy developed by these extinct flying reptiles.
The material consists of a large skull (length: 1420 millimeters, including the crest) with a huge bony crest that was well
irrigated by blood vessels and may have been used for regulation of its body temperature. The rostrum consists of two bladelike
laminae, the arrangement of which is analogous to the condition found in the bird Rynchops, which skims over the water to catch food, indicating that T. sethialso may have been a skimmer.
Fieldwork in the Early Cretaceous Jehol Group, northeastern China has revealed a plethora of extraordinarily well-preserved fossils that are shaping some of the most contentious debates in palaeontology and evolutionary biology. These discoveries include feathered theropod dinosaurs and early birds, which provide additional, indisputable support for the dinosaurian ancestry of birds, and much new evidence on the evolution of feathers and flight. Specimens of putative basal angiosperms and primitive mammals are clarifying details of the early radiations of these major clades. Detailed soft-tissue preservation of the organisms from the Jehol Biota is providing palaeobiological insights that would not normally be accessible from the fossil record.
Dinosaur embryos have been discovered all over the world, but so far no pterosaur embryos have been reported. Here we describe a Chinese fossil from the Early Cretaceous period containing an embryo that is unambiguously a pterosaur. The embryonic skeleton, which is exquisitely preserved in its egg, is associated with eggshell fragments, wing membranes and skin imprints. This discovery confirms that pterosaurs were egg-layers and sheds new light on our understanding of pterosaur development.
New specimens and an analysis of the Jehol pterosaur faunae of northeastern China show an unexpected diversity of flying reptile groups in terrestrial Cretaceous ecosystems. Here we report two new pterosaurs that are referred to European groups previously unknown in deposits of northeastern China. Feilongus youngi, from the Yixian Formation, is closely related to the Gallodactylidae and is distinguished by the presence of two independent sagittal crests and a protruding upper jaw. Nurhachius ignaciobritoi, from the Jiufotang Formation, has teeth formed by labiolingually compressed triangular crowns, only previously reported in Istiodactylus latidens from England. With these new discoveries, the Jehol pterosaurs show a wide range of groups including both primitive and derived forms that are not matched by any other deposit in the world. The discoveries also document the turnover of pterosaur faunae, with the primitive Anurognathidae and early archaeopterodactyloids being replaced by derived pterodactyloids. Furthermore, these deposits offer an opportunity to examine the interaction and competition between birds and pterosaurs--it indicates that the avian fauna during the Lower Cretaceous (and possibly most of the Mesozoic) dominated terrestrial, inland regions, whereas pterosaurs were more abundant in coastal areas.
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.
A new incomplete pterosaurian skeleton, Eosipterus yangi gen. et sp. nov. , collected from western Liaoning is briefly described. It is the first occurrence of the pterosaurs from the famous Jehol Fauna in Northeast China; thus it is of great value to biostratigraphy and biogeography. According to the nature of the new pterosaur and other fossils in the same beds, this flying animal is supposed to have lived along the coast of a large freshwater lake which developed during the Late Jurassic and Early Cretaceous. The new genus and species should be assigned to the suborder Pterodactyloidea. Its main characters are given as follows: Medium-sized pterodactyloid pterosaur with a total width about 1.2m across two ends of distal wing-fingers. Tail short. Gastralia narrow and weak. Forelimb strong; radius and ulna 1.3 times as long as wing-metacarpal. Wing-finger joints extensible transversely. Femur slightly straight, occupying the 2/3 length of tibia. Radius, the first wing-finger as long as tibia. Metatarsal I-IV long and narrow; phalange V of hindlimb degenerated and small.
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.
The anatomy of the wings of pterosaurs is described. The wings seem to have been attached along the body to the thigh in at least one specimen of the genus Pterodactylus, but the extent of the posterior attachment of the wings is not definitely known in other genera. The pelvic girdles of pterosaurs were focused along their ventromedial symphyses, at least in adults. The orientation of the acetabulum varied, as it does in birds, but the hindlimbs were organized along the plan seen in birds and other dinosaurs. This evidence indicates that pterosaurs had an erect posture and parasagittal gait. The assumption that their pelves were too weak to support muscles for bipedal locomotion is incorrect: many animals with known bipedal locomotory abilities lack hard part structures with comparable muscle attachment areas. -from Authors
Pterosaurs are represented in China by five genera and some isolated
bones ranging in age from the Middle Jurassic to the Late Cretaceous
period. Four of these genera belong to the derived monophyletic subgroup
Pterodactyloidea; only the Middle Jurassic Angustinaripterus from
Dashanpu, Sichuan, is a non-pterodactyloid (traditionally
`rhamphorhynchoids', a paraphyletic taxon). Two further pterosaurs (Fig.
1) from the Chaomidianzi Formation of the Beipiao area, western Liaoning
Province, occur in the Liaoning beds, several metres higher than the
compsognathid coelurosaur Sinosauropteryx and the basal bird
Confuciusornis. Our analysis of these two fossils and other components
of the fauna suggest a Late Jurassic biostratigraphic age for the
Liaoning beds, which are important in the study of avian origins.
Numerous remains of the azhdarchid pterosaur Quetzalcoatlus sp., have been recovered over the last twenty years from the Late Cretaceous (Maastrichtian) rocks in Big Bend National Park in Trans-Pecos Texas. Among more than 200 bones found at one locality are four incomplete skulls and mandibles, which provide the most complete information about cranial structures in the Azhdarchidae. What is currently known indicates that the Azhdarchidae is the sister group of the Tapejaridae from Early Cretaceous deposits in northeastern Brazil.
A cladistic analysis based on 39 terminal taxa and 74 characters (several multistate) using PAUP (Phylogenetic Analysis Using Parsimony) (3.1.1 for MacIntosh and 4.0b10 for Microsoft Windows) presents a new hypothesis of pterosaur inter-relationships. This study suggests that the most primitive taxon is the Anurognathidae, followed by Sordes and all remaining pterosaurs. Dendrorhynchoides is confirmed as a member of the Anurognathidae, being closely related to Batrachognathus. Preondactylus occupies a more derived position than Sordes , which questions its previous assignment as the most primitive pterosaur. The hypothesis of rhamphorhynchoid paraphyly is confirmed, with the Rhamphorhynchidae more closely related to the Pterodactyloidea than to more basal forms. The Pterodactyloidea shows a basal dichotomy: the Archaeopterodactyloidea and the Dsungaripteroidea. The Archaeopterodactyloidea is formed by Pterodactylus + Germanodactylus and a clade formed by Gallodactylidae + Ctenochasmatidae. The Nyctosauridae occupies the basal position within dsungaripteroids and is followed by the Pteranodontoidea and the Tapejaroidea. Pteranodontoids have Pteranodon at the base, followed stepwise by Istiodactylus, Ornithocheirus and the Anhangueridae. Tapejaroids are composed of the Dsungaripteridae at the base followed by the Tapejaridae and the Azhdarchidae.
Major trends within pterosaur evolutionary history are: general increase in size (wing span and body); increase of wing metacarpal and pteroid; decrease of proportional length of the second and third wing phalanx relative to the first; gradual increase of rostrum (anterior to external nares); and anterior shift of the skull-mandible articulation. Cranial crests are present in most pterodactyloids, but markedly in the Ornithocheiroidea, where all taxa show some sort of crest on the skull. The loss of teeth, previously assumed to have occurred independently in several lineages, seems to be a general trend among dsungaripteroids.
Several nodes recovered by this analysis are supported by very few characters, a result at least partially attributable to the limited available information from several taxa due to poor preservation and/or preparation.
Soft tissues associated with the cranial crest are described in a specimen of Germanodactylus rhamphastinus from the Solnhofen Limestone of southern Germany. The soft tissues covered, and extended upward from, the bony premaxillary crest, more than doubling the height of the crest, and were probably composed of cornified epidermis. Comparison of this specimen with other Solnhofen pterodactyloids with premaxillary crests suggests that all had soft tissues increasing the size of the crest in life.
Abstract Based on a nearly complete lower jaw from the Early Cretaceous of Liaoning Province, a new ctenochasmatid pterosaur: Liaoxipterus brachyognathus gen. et sp. nov. is erected. Liaoxipterus brachyognathus is different from any known pterosaurs with skulls preserved from western Liaoning Province and its peripheral areas in that the anterior part of the mandibular symphysis is expanded, being widest between the fourth alveolus of each side. Liaoxipterus brachyognathus is assigned to Ctenochasmatidae based on the following characters: the rounded anterior end of the lower jaw is spatulated and dorsoventrally flattened and marked heterodonty in the dentition is absent. It differs from other ctenochasmatid pterosaurs in having relatively small number of teeth. Liaoxipterus is distinguished from some oenithocheirids, which have expanded anterior parts of the mandibular symphyses, such as Anhanguera piscator, Coloborhynchus robustus in which the teeth of the new pterosaur are not as variable.
The pterosaur from the Yixian Formation in Beipiao, Liaoning Province, is characterized by the medium–sized individual, short tail, presence of the gastralia, strong forelimbs, radius and ulna longer than wing–metacarpal, extremely narrow and elongate metatarsals, degenerated and small phalanx V of hindlimb and so on. It must be a new genus and species, Eosipterus yangi gen. et sp. nov., in the early groups of the Suborder Pterodactyloidea. This is the first record of pterosaurs found in Liaoning Province. The fossil provides new evidence for further determining the nature and geological time of the Jehol Fauna and for studying the palaeogeography and palaeoenvironment.
Abstract A nearly complete skeleton with a lower jaw of pterosaur from the Early Cretaceous of western Liaoning is described and assigned to a new genus, Eoazhdarcho gen. nov. The new genus is characterized by a relatively small size, the ratio of the length to width of the middle series cervical vertebrae approximately 3.5 and the ratio of humeral length to femoral length approximately 0.96. The humerus of Eoazhdarcho shows great resemblances to that of previously described Azhdarchidae, so it is assigned to the family Azhdarchidae.
Abstract Based on a nearly complete skeleton with skull from the Early Cretaceous of Liaoning Province, a new ornithocheirid pterosaur: Boreopterus cuiae gen. et sp. nov. is erected. Boreopterus cuiae is different from other pterosaurs preserved with skulls known from the western Liaoning Province and its neighboring areas. This new pterosaur has more and larger teeth than those in other ornithocheirids. Its anterior nine pairs of teeth are larger than other teeth. The fourth pair of upper and lower teeth are slightly larger than the third pair. Overall, Boreopterus cuiae shows much small range of tooth size variation than Anhanguera piscator and Coloborhynchus robustus. The new taxon shares with other ornithocherids in having a relatively large size of the third and fourth pairs of teeth.
Previous cladistic studies of pterosaur relationships suffer from restricted numbers of taxa and characters, incomplete data sets and absence of information on characters, tree structure and the robustness of trees. Parsimony analysis of a new character data set (60 characters, 20 terminal taxa, 93.75% complete) yielded six trees. In the strict consensus tree Preondactylus is the most basal taxon followed, stepwise, by the Dimorphodontidae and the Anurognathidae. Beyond this basal group, more derived pterosaurs (Campylognathoididae (Rhamphorhynchidae + Pterodactyloidea)) share a suite of characters principally associated with elongation of the rostrum. The Pterodactyloidea consists of four major clades. The Ornithocheiroidea is the most basal taxon consisting, stepwise, of Istiodactylus, the Ornithocheiridae, Nyctosaurus and the Pteranodontidae. The remaining taxa, Ctenochasmatoidea, Dsungaripteroidea and Azhdarchoidea, are weakly united in a clade of non-ornithocheiroid pterodactyloids, but their inter-relationships are difficult to resolve. Cycnorhamphus is the basal-most ctenochasmatoid, while the remaining taxa (Pterodactylus, Lonchodectidae, Ctenochasmatidae) form an unresolved trichotomy. The Dsungaripteroidea (Germanodactylus + Dsungaripteridae) is strongly supported by features of the skull and dentition. The Azhdarchoidea (Tapejara [Tupuxuara + Azhdarchidae]) is united by cranial characters such as elevation of the antorbital region, and relative shortening of the wing finger. The pattern of pterosaur evolution suggested by the results of this analysis is broadly similar to traditional ideas, but has greater resolution, more complexity and reveals several previously unrecognized 'events'.