164 research outputs found
Scapegoat of the Empire: George Witton and the Breaker Morant Affair
No full textMark Cryle, Fryer Library Manager, examines the role of George Witton in shaping our understanding of the Breaker Morant affair
A medium-sized robust-necked azhdarchid pterosaur (Pterodactyloidea: Azhdarchidae) from the Maastrichtian of Pui (Ha?eg Basin, Transylvania, Romania)
No full textFIG. 1. Map of the Haţeg Island region, present-day Transylvania (Romania). The contemporaneous Transylvanian and Haţeg basins are indicated; the Pui locality is just a few kilometers from the town of Haţeg.Published as part of Vremir, Mátyás, Witton, Mark, Naish, Darren, Dyke, Gareth, Brusatte, Stephen L., Norell, Mark & Totoianu, Radu, 2015, A medium-sized robust-necked azhdarchid pterosaur (Pterodactyloidea: Azhdarchidae) from the Maastrichtian of Pui (Haţeg Basin, Transylvania, Romania), pp. 1-16 in American Museum Novitates 2015 (3827) on page 4, DOI: 10.1206/3827.1, http://zenodo.org/record/536804
Azhdarchid pterosaurs: water-trawling pelican mimics or ‘terrestrial stalkers’?
No full textThe lifestyles of all pterosaurs are contentious, but those of the pterodactyloid clade Azhdarchidae are particularly debated. A 2008 review of the functional morphology of azhdarchid pterosaurs concluded that they were probably terrestrial foragers, as evidenced by their long limbs, generalised skull construction, the arthrological limitations of their cervical series, trackway data indicating terrestrial proficiency, a strong continental skew in the depositional context of their fossils, and several additional lines of corroborating evidence. This hypothesis was recently challenged on three counts: (i) azhdarchid fossils routinely occur in aquatic deposits; (ii) terrestrially-foraging pterosaurs were highly vulnerable to predation and (iii), aerial “water trawling”, where the mandible is pulled though water to catch food in a distended throat pouch, is a more likely foraging strategy. Pelican-like jaw mechanics were suggested for azhdarchids because of the asymmetrical jaw joints in these pterosaurs, which permit lateral deflection of the mandibular rami during jaw extension. We evaluate these three claims and conclude that all are flawed. The frequent occurrence of azhdarchid fossils in aquatic sedimentary systems is not significant with regard to ecology or behaviour, since these provide the overwhelming mechanism for the preservation of all fossil terrestrial animals. Likely pterosaur takeoff abilities and the ubiquitous nature of modern, terrestrially-foraging birds indicate that predation risks on ground-foraging pterosaurs are probably overstated. The kinematics of pterosaur jaws are entirely different to those of pelicans, which are highly specialised compared to those of all other tetrapods, and there are no indications from azhdarchid jaw anatomy that azhdarchids indulged in pelican- like foraging behaviour. The estimated amount of jaw expansion present in azhdarchids was minimal compared to that of pelicans, even when the asymmetrical jaw joints of azhdarchids are taken into account. Moreover, the widespread occurrence of asymmetrical jaw joints in other reptiles demonstrates that they are not related to any specific feeding habits. We conclude that terrestrial foraging remains the most parsimonious habit for azhdarchid pterosaurs
State of the Palaeoart
No full textThe discipline of palaeoart, a branch of natural history art dedicated to the reconstruction of extinct life, is an established and important component of palaeontological science and outreach. For more than 200 years, palaeoartistry has worked closely with palaeontological science and has always been integral to the enduring popularity of prehistoric animals with the public. Indeed, the perceived value or success of such products as popular books, movies, documentaries, and museum installations can often be linked to the quality and panache of its palaeoart more than anything else
New insights into the skull of Istiodactylus latidens (Ornithocheiroidea, Pterodactyloidea)
No full textThe skull of the Cretaceous pterosaur Istiodactylus latidens, a historically important species best known for its broad muzzle of interlocking, lancet-shaped teeth, is almost completely known from the broken remains of several individuals, but the length of its jaws remains elusive. Estimates of I. latidens jaw length have been exclusively based on the incomplete skull of NHMUK R3877 and, perhaps erroneously, reconstructed by assuming continuation of its broken skull pieces as preserved in situ. Here, an overlooked jaw fragment of NHMUK R3877 is redescribed and used to revise the skull reconstruction of I. latidens. The new reconstruction suggests a much shorter skull than previously supposed, along with a relatively tall orbital region and proportionally slender maxilla, a feature documented in the early 20(th) century but ignored by all skull reconstructions of this species. These features indicate that the skull of I. latidens is particularly distinctive amongst istiodactylids and suggests greater disparity between I. latidens and I. sinensis than previously appreciated. A cladistic analysis of istiodactylid pterosaurs incorporating new predicted I. latidens skull metrics suggests Istiodactylidae is constrained to five species (Liaoxipterus brachyognathus, Lonchengpterus zhoai, Nurhachius ignaciobritoi, Istiodactylus latidens and Istiodactylus sinensis) defined by their distinctive dentition, but excludes the putative istiodactylids Haopterus gracilis and Hongshanopterus lacustris. Istiodactylus latidens, I. sinensis and Li. brachyognathus form an unresolved clade of derived istiodactylids, and the similarity of comparable remains of I. sinensis and Li. brachyognathus suggest further work into their taxonomy and classification is required. The new skull model of I. latidens agrees with the scavenging habits proposed for these pterosaurs, with much of their cranial anatomy converging on that of habitually scavenging birds
A small azhdarchoid pterosaur from the latest Cretaceous, the age of flying giants
No full textPterosaur fossils from the Campanian–Maastrichtian of North America have been reported from the continental interior, but few have been described from the west coast. The first pterosaur from the Campanian Northumberland Formation (Nanaimo Group) of Hornby Island, British Columbia, is represented here by a humerus, dorsal vertebrae (including three fused notarial vertebrae), and other fragments. The elements have features typical of Azhdarchoidea, an identification consistent with dominance of this group in the latest Cretaceous. The new material is significant for its size and ontogenetic stage: the humerus and vertebrae indicate a wingspan of ca 1.5?m, but histological sections and bone fusions indicate the individual was approaching maturity at time of death. Pterosaurs of this size are exceedingly rare in Upper Cretaceous strata, a phenomenon commonly attributed to smaller pterosaurs becoming extinct in the Late Cretaceous as part of a reduction in pterosaur diversity and disparity. The absence of small juveniles of large species—which must have existed—in the fossil record is evidence of a preservational bias against small pterosaurs in the Late Cretaceous, and caution should be applied to any interpretation of latest Cretaceous pterosaur diversity and success
Dorsal views of giant and tiny pterosaur humeri.
No full text<p>A, <i>Quetzalcoatlus northropi</i> (10–11 m wingspan); B, <i>Pteranodon</i> (7 m wingspan); C, <i>Pterodactylus</i> (45 cm wingspan). Note that each bears a large deltopectoral crest (dp) and robust extremities. Scale bars represent 100 mm (A and B) and 10 mm (C). A and C, from Witton <i>et al. </i><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0013982#pone.0013982-Witton4" target="_blank">[121]</a>; B, modified from Bennett <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0013982#pone.0013982-Bennett2" target="_blank">[12]</a>.</p
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