Authors:Jiang et alAbstract: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 in different pterosaur taxa.
Showing posts with label pterosaurs. Show all posts
Showing posts with label pterosaurs. Show all posts
Friday, September 23, 2016
Forfexopterus jeholensis: a new Archaeopterodactyloid Pterosaur From Cretaceous China
Labels:
Archaeopterodactyloid,
china,
cretaceous,
fossils,
orinthodirans,
paleontology,
pterosaurs
Friday, September 16, 2016
Allkaruen koi: a new Patagonian Pterosaur From the Lower Jurassic
Scientists today announced the discovery of a new species of pterosaur from the Patagonia region of South America. The cranial remains were in an excellent state of preservation and belonged to a new species of pterosaur from the Early Jurassic. The researchers have named this new species 'Allkauren koi' from the native Tehuelche word 'all' for 'brain', and 'karuen' for 'ancient'.
Pterosaurs are an extinct group of flying reptiles that lived during most of the Mesozoic Era. This group had an extraordinary adaptation to flight, including pneumatic bones to lighten its weight, and an elongated digit supporting a wing membrane. However, pterosaur neuroanatomy is known from only a few three dimensionally preserved remains and, until now, there was no information on the intermediate forms. This study therefore provides new information on the origin, tempo and mode of evolution in this particular group of flying reptiles.
The fossil of Allkaruen koi was found in northern central Chubut Province, Patagonia Argentina and the remains included a superbly preserved and uncrushed braincase. In order to study the neurocranial anatomy, researchers used computed tomography to observe, in three dimensions, the cranial endocast and the inner ear. Subsequently, a comprehensive phylogenetic analysis of the group was performed, including these cranial data and other anatomical features. "Allkaruen, from the middle lower jurassic limit, shows an intermediate state in the brain evolution of pterosaurs and their adaptations to the aerial environment", said Dr Diego Pol, who is part of the research team. "As a result, this research makes an important contribution to the understanding of the evolution of all of pterosaurs."
link.
Labels:
argentina,
fossils,
Jurassic,
mesozoic,
paleontology,
patagonia,
pterosaurs
Friday, September 02, 2016
A New Small Pterosaur From Late Cretaceous North America
As the Cretaceous fossil record enters its final two stages - the Campanian and Maastrichtian - several unusual things seem to happen in the world of flying reptiles. Firstly, we see the end result of a steady drop off in pterosaur diversity leaving only azhdarchids - those often long-necked, long faced animals that we cover here with some regularity - with a strong, widespread fossil record. It's known that nyctosaurids and (thanks to recent discoveries) perhaps pteranodontids survived until the very end of the Mesozoic in at least two locations, but azhdarchids are globally distributed and dominate the pterosaur fossil record at this time. The overwhelming precedence of azhdarchids in the Late Cretaceous is an anomaly: at no other point in the pterosaur fossil record does one clade feature so prominently.
Secondly, Campanian and Maastrichtian pterosaurs are, without exception, pretty big animals. Many species from this time are renowned for their gigantic size: it's these stages which give us the famous 10 m wingspan, 250 kg colossi like Quetzalcoatlus, Arambourgiania and Hatzegopteryx, as well as a number of other giant azhdarchids which are too poorly known for generic titles. Coinciding with the evolution of the giants is a loss of small pterosaur taxa - those animals less than 2.5 m across the wings which are present, more-or-less, throughout the rest of pterosaur history. This shift in body size is sometimes interpreted as pterosaurs demonstrating 'Cope's Rule', the somewhat controversial proposal that species evolve towards large body size over time (Hone and Benton 2007; Benson et al. 2014). It's argued by some that competition from birds may be the driver behind this trend, as early avians fought small flying reptiles for ecological space and ultimately forced pterosaurs into larger sizes (e.g. Benson et al. 2014). Note that this concept is not without its detractors, including myself - I won't go into my reasons now but I plan to outline them here eventually.
Whether you agree with the bird-pterosaur competitive displacement hypothesis or not, we can't disagree that the end of the Cretaceous is almost entirely devoid of small pterosaur remains. Only a handful of specimens record small pterosaurs in the Campanian and Maastrichtian, and they're all tricky to work with. Aside from being highly fragmentary, some are controversially identified (such as Piksi barbarulna, an alleged small pterosaur from the Two Medicine Formation - see Agnolin and Varricho 2012 for the pro-pterosaur case) and others represent probable juvenile individuals (Godfrey and Currie 2005). Whatever it signifies, the lack of diminutive pterosaur specimens from the close of the Mesozoic is a real phenomenon of our fossil record, and any new specimen of a small, latest Cretaceous flying reptile has to be something to get excited about.
link.
Labels:
azhdarchoid,
cretaceous,
fossils,
late cretaceous,
mesozoic,
paleontology,
pterosaurs
Thursday, July 28, 2016
Mark Witton Reexamines Pteranodon
Writing about pterosaurs can be difficult because so much of their classification is disputed. The number of pterosaur species, their assignment to different groups, appropriate clade nomenclature and the arrangement of branches in the pterosaur tree are all contested, sometimes to polarising extents.
A bastion of taxonomic stability in all this is Pteranodon, everyone's favourite giant, toothless Late Cretceous ornithocheiroid (or pteranodontoid) from interior regions of the United States. Known since the late 1860s, Pteranodon is one of the most substantially sampled of all pterosaurs and we now have well over 1100 specimens in museums around the world. This record stems from a relatively limited geographical area and is constrained stratigraphically to the Smoky Hill Chalk Member of the Niobrara Formation, with a smattering of fossils from the overlying Pierre Shale Group.
A series of papers documenting Pteranodon anatomy, variation and stratigraphy, all penned by pterosaur expert S. Christopher Bennett during the 1980s-2000s, have made this pterosaur one of the best understood of all flying reptiles (perhaps the most important entries in this series are Bennett 1992, 1993, 1994, 2001a, 2001b). These publications are the result of examining several hundred Pteranodon specimens and are among the most significant and comprehensive contributions to pterosaur literature in modern times. I recommend them to any students of vertebrate palaeontology: even if you don't agree with their conclusions, they're great examples of clear writing, of hypotheses being established and tested, and of large amounts of data being presented clearly and logically.
link.
Labels:
fossils,
links,
paleobiology,
paleontology,
pterosaurs
Tuesday, June 28, 2016
Mark Witton Delves Into Giant Azhdarchid Pterosaur Arambourgiania
When people talk about giant azhdarchid pterosaurs (odds are most readers of this blog don't need an introduction to azhdarchids, but if you do, click here) they typically mention two taxa. The first is Quetzalcoatlus northropi, a giant Texan pterosaur discovered in the 1970s and now one of the most famous pterosaurs of all (Lawson 1975, Langston 1981). The second is Hatzegopteryx thambema, a relatively robust giant discovered in the 1990s and initially - because of its size and reinforced bone construction - thought to be a giant predatory dinosaur (see Buffetaut et al. 2003). From internet forums to TV show producers, if you want to chat about giant pterosaurs, these species are your most likely subjects.
Many readers will be aware that these aren't the only giant azhdarchids, however. The record of these animals cannot be described as extensive, but it is sufficient to indicate that they were present across most of the world and probably not particularly rare in Late Cretaceous ecosystems. But most fossils of giant azhdarchids are unnameable on account of being too fragmentary, being represented by parts of undiagnostic anatomy, or being too poorly preserved. This makes it all the more surprising that the third named giant azhdarchid doesn't get much attention: the Maastrichtian species Arambourgiania philadelphiae, known from several bones from phosphate mines in Jordan.
I'm not sure why we generally overlook this giant. Perhaps it's because Arambourgiania - 'Arambourg's giant' - is one of those old-fashioned names which works better in translation than the original Greek. It certainly doesn't sound as evocative or exotic as Quetzalcoatlus or Hatzegopteryx. Moreover, it's the least known of the three named giants, being primarily represented by a long - 620 mm - cylindrical neck vertebra, and not much else. The other named giants are not well represented either, but we have more than a handful of bones for them, and they're represented by intuitively intriguing anatomies: giant wing skeletons, bits of skull and jaw and so on. But whatever the cause, there are reasons to consider our relative neglect of Arambourgiania as unwarranted. It may not be as well-known as Quetzalcoatlus, or as immediately intriguing as Hatzegopteryx, but if you're interested in giant azhdarchids (and, hey, who isn't?) you this animal deserves your attention just as much as the other species. Here are just three reasons why.
link.
Labels:
cretaceous,
fossils,
mesozoic,
paleontology,
pterosaurs
Wednesday, June 08, 2016
Gladocephaloideus: a new Ctenochasmatoid Pterosaur From Cretaceous CHina
New Material of the Pterosaur Gladocephaloideus Lü et al., 2012 from the Early Cretaceous of Liaoning Province, China, with Comments on Its Systematic Position
Authors:
Lü et al
Abstract:
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.
Labels:
china,
cretaceous,
ctenochasmatoids,
mesozoic,
orinthodirans,
paleontology,
pterosaurs
Sunday, May 01, 2016
Mark Witton on Pterosaur Rhamphorhynchus
The Late Jurassic, Solnhofen Formation pterosaur Rhamphorhynchus muensteri is an exceptional flying reptile. We tend to overlook it a bit now - it's been known for almost two centuries, which is long enough to temper enthusiasm for any fossil species - but it's a remarkable animal for a number of reasons. Far from a typical example of the rhamphorhynchid lineage, it's the rhamphorhynchiest of all pterosaurs with a jaw full of large, conical teeth, elongate extensions to its jaw tips, exceptionally long and slender wings, delicate hindlimbs and walking digits, and a long, stiff tail famously adorned with a diamond or triangular shaped vane*. It also arguably has the best fossil record of any pterosaur. It's known from over 100 specimens, many of them being complete, articulated skeletons with at least some three-dimensionality, as well as providing excellent soft-tissues remains. Excepting embryos, we have complete growth series from tiny juveniles to chunky adults with 1.8 m wingspans, and its preservation is such that fine details of bones can be gleaned through careful mechanical or acid preparation. Its osteology is subsequently better known that any other pterosaur. The Cretaceous pterodactyloid Pteranodon might be known from more fossils (greater than 1400), but these flattened, disarticulated remains are nowhere close to the fossil quality of Rhamphorhynchus.
link.
Labels:
fossils,
Jurassic,
mesozoic,
paleobiology,
paleontology,
pterosaurs,
Rhamphorhynchus
Monday, April 25, 2016
New interpretation of the wings of the pterosaur Rhamphorhynchus muensteri
New interpretation of the wings of the pterosaur Rhamphorhynchus muensteri based on the Zittel and Marsh specimens
Author:
Bennett
Abstract:
The Zittel wing of Rhamphorhynchus muensteri is reinterpreted as preserving negative impressions of closely spaced broad flat actinofibrils that were replaced by calcite but were prepared away by the specimen’s finder. The Marsh specimen preserves positive impressions of the dorsal and ventral surfaces of the wing, which show that the skin was smooth with fine wrinkles and that actinofibrils were not on the wing surface. Based on comparisons of those specimens, the dactylopatagium consisted of dorsal and ventral skins of epidermis and dermis surrounding a common hypodermis core, and keratinous actinofibrils developed in place within the dorsal epidermis adjacent to a layer of linear collagen fibers in the dorsal dermis. The actinofibrils and linear collagen fibers together formed the main functional structure of the dactylopatagium. That structure made the dactylopatagium somewhat stiff and essentially inextensible so that it folded up along discrete fold lines that probably were genetically determined. A pneumatic retrophalangeal wedge behind the antebrachium through at least wing phalanx 3 streamlined the transition between the thick wing spar and thin patagium.
Labels:
fossils,
mesozoic,
paleontology,
pterosaurs,
Triassic
Monday, April 11, 2016
New Findings in the Study of Feathered Dinosaurs and Pterosaurs
New Findings in the Study of Feathered Dinosaurs and Pterosaurs
Authors:
???
Abstract:
An oviraptorid dinosaur Huanansaurus ganzhouensis, belonging to the derived oviraptorid dinosaur, was discovered from the Late Cretaceous deposits in Ganzhou, Jiangxi Province. Its unique skull characteristics provide a new insight into the craniofacial evolution of oviraptorosaurid dinosaurs, paleogeographical distribution and paleoecological environments. Zhenyuanlong suni from the Early Cretaceous Yixian Formation of western part of Liaoning Province is a large, short-armed, winged dromaeosaurid dinosaur. It provides the evidence of feather morphologies and distribution in a short-armed dromaeosaurid dinosaur. The discovery of Zhenyuanlong also provides important evidence for the study of the diversity, the origin of feathers and the flight of Liaoning dromaeosaurid dinosaurs. Orientognathus chaoyngensis is the first Late Jurassic pterosaur discovered in western Liaoning and it is the largest rhamphorhynchinae pterosaur. The discovery of Orientognathus not only fills the temporal gap between the Middle Jurassic and Early Cretaceous pterosaur faunas of China but also plays an important role in the understanding of radiation evolution of rhamphorhynchids from the Late Jurassic. The above-mentioned important discoveries play a key role in our understanding of the hot and difficult issues such as the evolution of oviraptorid dinosaurs, the feather evolution in dromaeosaurid dinosaurs and the origin of bird feathers. In particular, the Ganzhou Dinosaurian Fauna is named based on the discovery of Huanansaurus.
Labels:
china,
dromaeosaur,
feathers,
fossils,
nonavian dinosaurs,
oviraptorosaurs,
paleontology,
pterosaurs,
rhamphorhynchoid,
theropods
Saturday, February 13, 2016
Wednesday, January 06, 2016
Liaoningopterus gui: a new Toothed Pterosaur From Aptian Cretaceous China
A new toothed pteranodontoid (Pterosauria, Pterodactyloidea) from the Jiufotang Formation (Lower Cretaceous, Aptian) of China and comments on Liaoningopterus gui Wang and Zhou, 2003
Authors:
Rodrigues et al
Abstract:
Pteranodontoids consist of a diverse and cosmopolitan clade of Cretaceous pterodactyloid pterosaurs. In the Jiufotang Formation (Lower Cretaceous, Aptian) of northeastern China, pterodactyloids are represented by azhdarchoids and pteranodontoids, including istiodactylids and anhanguerians. Here, we describe a new pterosaur from this unit that represents a new species of toothed pteranodontoid. Its overall morphology is consistent with other toothed pteranodontoids but shows some interesting features such as the orbit being more ventrally positioned than in all other species from this clade. It differs markedly from all other pterosaurs from this unit, including Liaoningopterus, Guidraco and Ikrandraco, with which the new taxon is possibly related. In addition to the description of the new taxon, we also describe the anhanguerid Liaoningopterus gui in more detail. The new species, Liaoningopterus gui, Guidraco venator and Ikrandraco avatar, are large pterosaurs with very distinct tooth morphologies, suggesting that they had different prey preferences, partially explaining how the Jiufotang Formation could bear such a high diversity of pterosaur species.
Labels:
aptian,
china,
cretaceous,
fossils,
mesozoic,
paleontology,
pterosaurs
"Giant" Pterosaur Found at Rhaetian (?) Triassic Oasis "Sandpit"
Scientists have found an unprecedented cache of fossils of weird animals that thrived at a desert oasis some 200 million years ago, providing a snapshot of a place and time that have long been a mystery.
The fossils include the bones of a fanged flying predator and creatures that looked, one scientist says, like tiny crocodiles with a Chihuahua's legs. Small reptiles whose "hands" resemble a mole's lived alongside dinosaurs that scampered on their hind legs.
Researchers suspect that many of the fossils represent entirely new species.
"Probably almost everything we're finding (at the site) is previously unknown to science," says Dan Chure of Dinosaur National Monument, one of the site's co-discoverers. "It's just an amazing paleontological candy shop."
The fossils are "a spectacular find," agrees University of Utah paleontologist Randall Irmis, who isn't involved in the project. "We so rarely get sites that preserve such a variety of different animals from the beginning of the age of dinosaurs."
The animals at the site should help illuminate the period just before the mass extinction that allowed the dinosaurs to take over the Earth, Irmis says. The fossils also illuminate exactly what was living in the vast sand box that filled what is now the western United States, where fossils from the Late Triassic fossils are scarce.
link.
Labels:
crocodylians,
dinosaurs,
late triassic,
pterosaurs,
rhaetian,
Triassic,
Utah
A Rhamphorhynchus With Soft Tissue and What it ate
A specimen of Rhamphorhynchus with soft tissue preservation, stomach contents and a putative coprolite
Authors:
Hone et al
Abstract:
Despite being known for nearly two centuries, new specimens of the derived non-pterodactyloid pterosaur Rhamphorhynchus continue to be discovered and reveal new information about their anatomy and palaeobiology. Here we describe a specimen held in the collections of the Royal Tyrrell Museum of Palaeontology, Alberta, Canada that shows both preservation and impressions of soft tissues, and also preserves material interpreted as stomach contents of vertebrate remains and, uniquely, a putative coprolite. The specimen also preserves additional evidence for fibers in the uropatagium.
Labels:
fossils,
mesozoic,
paleobiology,
paleontology,
pterosaurs,
soft tissue,
Triassic
Monday, January 04, 2016
Very Diverse Dinosaur Trackway has Ornithopod and Pterosaur Traces Amongst Lots of Theropod and Sauropods Tracks
A diverse saurischian (theropod–sauropod) dominated footprint assemblage from the Lower Cretaceous Jiaguan Formation in the Sichuan Basin, southwestern China: A new ornithischian ichnotaxon, pterosaur tracks and an unusual sauropod walking pattern
Authors:
Xing et al
Abstract:
A sample of fallen blocks of fluvial sandstone from the Lower Cretaceous Jiaguan Formation of Sichuan Province yielded an assemblage of dinosaur and pterosaur tracks preserved as natural impressions and casts. Collectively the assemblage reveals 132 tracks representing at least 30 trackways of tridactyl and didactyl theropods, sauropods, ornithopods and pterosaurs. Ichnotaxonomically, the trackways of small tridactyl theropods (pes lengths 7–18 cm) are indeterminable, whereas the trackway of a small didactyl dromaeosaur (pes length up to 7.5 cm) is tentatively assigned to cf. Velociraptorichnus. The sauropod trackways are assigned to cf. Brontopodus based on the medium to nearly wide-gauge pattern. Other characteristics are the U-shaped manus and strong heteropody. One sauropod trackway shows a peculiar pattern with a lack of left manus imprints, and an unusual position and rotation of right manus imprints. Different scenarios and explanations for this phenomenon are discussed. Ornithopod trackways are the most abundant in the sample and characterized by pes imprints of a small biped that are assigned here to the new ichnospecies Caririchnium liucixini. It is characterized by an unusual broad shape and weak mesaxony. Bivariate analysis of different Caririchnium ichnospecies reveals increasing mesaxony toward the larger forms, a trend that is the reverse of typical theropod ichnotaxa, where large imprints have weak mesaxony. Three isolated, small pterosaur tracks (two manus, one pes) are visible on a single surface. They show strong similarities to the widespread ichnogenus Pteraichnus. This is the ninth report of tetrapod tracks from the Jiaguan Formation in recent years and represents one of the most diverse assemblages recorded to date. It is also rare evidence of typical didactyl dromaeosaur tracks and the co-occurrence of sauropod and ornithopod tracks in a fluvial depositional environment representing arid climate conditions.
Keywords
Labels:
cretaceous,
dinosaurs,
ichnology,
lower cretaceous,
mesozoic,
nonavian dinosaurs,
orinthopod,
paleodiversity,
pterosaurs,
sauropods,
theropods,
trace fossils,
trackways
Wednesday, November 04, 2015
Cimoliopterus dunni: a new Toothed Pterosaur From Cenomanian Cretaceous Texas
First North American occurrence of the toothed pteranodontoid pterosaur Cimoliopterus
Author:
Myers
Abstract:
A new pterosaur species, Cimoliopterus dunni, sp. nov., is described based on a partial rostrum from the upper Cenomanian Britton Formation in the Eagle Ford Group of north-central Texas. The holotype preserves alveoli for a minimum of 26 upper teeth and bears a thin premaxillary crest that begins above the fourth pair of alveoli. The rostrum, characterized by a slight lateral flare, lacks the pronounced lateral expansion found in ornithocheirids and anhanguerids. The tip of the snout is small and blunt, and the anterior face of the rostrum is oriented posteroventrally, forming an approximately 45° angle with the anterior portion of the palate. The anteroventrally oriented first pair of alveoli is directed more ventrally than anteriorly. Phylogenetic analysis suggests that Cimoliopterus dunni and Cimoliopterus cuvieri, from the Cenomanian Grey Chalk Subgroup in Kent, England, are basal pteranodontoids that are closely related to Aetodactylus halli from the middle Cenomanian Tarrant Formation of north Texas. Cimoliopterus dunni marks only the second known occurrence of Cimoliopterus, extending its geographic range from Europe to North America. In conjunction with Coloborhynchus wadleighi from the upper Albian Pawpaw Formation, Cimoliopterus dunni provides unambiguous evidence of biogeographic linkages between the pterosaur faunas of North America and Europe in the middle Cretaceous.
Labels:
cenomanian,
cretaceous,
fossils,
mesozoic,
orinthodirans,
paleontology,
pterosaurs,
Texas
Monday, September 07, 2015
The Form of Pterosaur Bellubrunnus' Wingtips Suggests a Unique Flight Profile
The wingtips of the pterosaurs: Anatomy, aeronautical function and ecological implications
Authors:
Hone et al
Abstract:
The leading edge and shape of the pterosaur wing is constrained by the skeleton. Although it has long been known that at least some pterosaurs had posteriorly curved distal wing phalanges, affecting the shape of the wingtip, this has been little studied despite that this may have profound effects on flight performance. Here we examine the evidence for curved wingtips in pterosaurs and evaluate the possible aerodynamic and aeronautical effects. Curved wingtips are shown to be common in both pterosaurs likely to have inhabited terrestrial environments, and those which were strongly pelagic. The recently described genus Bellubrunnus provides new anatomical novelty for pterosaurs having anteriorly directed wingtips and thus likely had a different flight profile to all previously known pterosaurs.
Labels:
fossils,
orinthodirans,
paleobiology,
paleontology,
pterosaurs
Tuesday, July 21, 2015
Pterosaurs had two Ovaries, Seem to Lack Medullary Bone
Eggshell and Histology Provide Insight on the Life History of a Pterosaur with Two Functional Ovaries
Authors:
Wang et al
Abstract:
The counterpart of a previously described non-pterodactyloid pterosaur with an egg revealed the presence of a second egg inside the body cavity of this gravid female. It clearly shows that pterosaurs had two functional oviducts and demonstrates that the reduction of one oviduct was not a prerequisite for developing powered flight, at least in this group. Compositional analysis of one egg suggests the lack of a hard external layer of calcium carbonate. Histological sections of one femur lack medullary bone and further demonstrate that this pterosaur reached reproductive maturity before skeletal maturity. This study shows that pterosaurs laid eggs even smaller than previously thought and had a reproductive strategy more similar to basal reptiles than to birds. Whether pterosaurs were highly precocial or needed parental care is still open to debate.
Labels:
fossils,
orinthodirans,
ovary,
paleobiology,
paleontology,
pterosaurs,
reproduction
Monday, July 20, 2015
Pterosaur -opolcalypse!
Comments on Triassic pterosaurs with discussion about ontogeny and description of new taxa
Author:
Kellner
Abstract:
Eudimorphodon ranzii was the first Triassic pterosaur to be described and several specimens have been referred to this taxon mainly based on the presence of multicuspid teeth. Since this dental feature has been observed in several other pterosaurs, the revision of some specimens assigned to Eudimorphodon shows that they represent new taxa as follows: Arcticodactylus cromptonellus (comb. nov.), Austriadraco dallavecchiai (gen. et sp. nov.) and Bergamodactylus wildi (gen. et sp. nov.). A preliminary analysis of pterosaur ontogeny resulted in the recognition of six distinct ontogenetic stages (OS1-6). According to this classification, the holotype of Arcticodactylus cromptonellus has reached OS2, and although being ontogenetically much younger than others, the conspicuous anatomical differences lead to its exclusion from Eudimorphodon. The holotypes of Austriadraco dallavecchiai, Bergamodactylus wildi and Carniadactylus rosenfeldi have reached at least OS5, which demonstrates that the anatomical differences among them cannot be explained by ontogeny. Moreover, Bergamodactylus wildi reaches about 60% of the maximized wingspan of Carniadactylus rosenfeldi and further concurs that these specimens collected in distinct Triassic Islands of Europe are not conspecific. The present study increases the diversity of Triassic flying reptiles and further pushes the origins of this clade back to at least the Middle Triassic.
Labels:
fossils,
mesozoic,
orinthodirans,
paleontology,
pterosaurs,
Triassic
Thursday, July 09, 2015
Wait! What!?! Pterosaur Liaoxipterus brachycephalus had a CHAMELEON-like TONGUE?!
The Hyoid Apparatus of Liaoxipterus Brachycephalus (Pterosauria) and Its Implications for Food-catching Behavior
Authors:
Lü et al
Abstract:
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.
Labels:
aptian,
barremian,
cretaceous,
fossils,
mesozoic,
paleobiology,
paleontology,
pterosaurs
Monday, May 18, 2015
Cuspicephalus scarfi is Really a Wukongopterid Pterosaur From Kimmeridgian Jurassic Britain
The relationships of Cuspicephalus scarfi Martill and Etches, 2013 and Normannognathus wellnhoferi Buffetaut et al., 1998 to other monofenestratan pterosaurs
Authors:
Witton et al
Abstract:
The evolution of pterodactyloid pterosaurs occurred in a ‘modular’ fashion with ‘pterodactyloid’-type crania and cervical vertebrae evolving in pterodactyloid sister taxa – early monofenestratan pterosaurs – before later postcervical modifications marked the development of the true pterodactyloid condition. This means of evolution creates problems for distinguishing isolated pterodactyloid crania from those of non-pterodactyloid monofenestratans, and has led to uncertainty over the affinities of two Late Jurassic European pterosaurs known only from skulls, Cuspicephalus scarfi Martill and Etches, 2013 and Normannognathus wellnhoferi Buffetaut et al., 1998. Some aspects of their cranial anatomy suggest affinities to early pterodactyloids – specifically the Germanodactylidae – while others indicate a relationship with a group of non-pterodactyloid monofenestratans, the Wukongopteridae. Here, we characterise the skulls of Jurassic monofenestratans to provide greater insight into the identity of these pterosaurs. We find a suite of characters indicating that Cuspicephalus is a wukongopterid, notable for being a particularly large and long snouted member of the group, as well as the youngest, and the first European record of this clade. The affinities of Normannognathus are less clear however. We consider its previous allocation to the Germanodactylidae doubtful, and note some similarities it shares with ctenochasmatoid pterodactyloids, but the only known specimen is probably too fragmentary for confident referral to any specific clade within Monofenestrata.
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Labels:
Britain,
fossils,
Jurassic,
Kimmeridgian,
mesozoic,
paleontology,
pterosaurs,
upper jurassic,
Wukongopterid
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