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TOPIC: Giant Pterosaur


L

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Mecistotrachelos apeoros
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A remarkable new long-necked, gliding reptile discovered in 220 million-year old sediments of eastern north America is described in the latest issue of the Journal of Vertebrate Palaeontology (Vol. 27, No. 2), scientists report. Mecistotrachelos apeoros (meaning "soaring, long-necked") is based on two fossils excavated at the Solite Quarry that straddles the Virginia-North Carolina state line.

"One of the really neat things about the new glider is the feet. They are preserved in a hooked posture which is unusual and strongly suggests a grasping habit, further emphasizing a life style in the trees" - Nick Fraser of the Virginia Museum of Natural History, who discovered the fossils.

It probably fed on insects, scuttling up tree trunks and foraging on the way, before gliding onto neighbouring trees.
Fraser said that while two other reptiles with similar gliding membranes are known from the Triassic Period, they have much shorter necks and therefore conform more to the modern gliding lizard, Draco.
The relationships of Mecistotrachelos are unclear, but Fraser considers that it is probably related to the protorosaurs. Protorosaurs are a group of extinct reptiles characterized by a long-necked, including the bizarre Tanystropheus which had a neck longer than the length of the body and tail combined.
Because of the nature of the sediments, it was not possible to prepare the fossils by standard mechanical methods and the descriptions are based entirely on CT scans. This technique has only been rarely used to describe new species. Tim Ryan of the Centre for Quantitative Imaging at Pennsylvania State University led the work on the CT scanning.

"This is a really cool little reptile which was very difficult to see until we looked at the CT scans" - Tim Ryan.

The other authors are Alton Dooley, also of the Virginia Museum of Natural History, and Paul Olsen of the Lamont Doherty Earth Observatory, Columbia University who originally discovered the site over 30 years ago.
The ongoing excavations at the quarry by the Virginia Museum of Natural History have been supported by the National Geographic Society and the US National Science Foundation.
Founded in 1940 by thirty-four palaeontologists, the Society of Vertebrate Palaeontology's more than 2,000 members represent professionals, students, artists, preparators, and others interested in vertebrate palaeontology. It is organized exclusively for educational and scientific purposes, with the object of advancing the science of vertebrate palaeontology. The Journal of Vertebrate Palaeontology is the Society's flagship publication and is the leading journal of professional vertebrate palaeontology.

Journal of Vertebrate Palaeontology

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L

Posts: 131433
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Rhamphorhynchoid pterosaurs
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A psychologist at a university in Central China asserts that he saw, in 1971, a prehistoric-looking creature flying in Papua New Guinea. Brian Hennessy of the Chongqing University of Medical Sciences described the creature as black or dark brown with a "longish narrow tail" and a beak that was "indistinguishable from the head."
In the daylight of an early morning on Bougainville Island, on a dirt road that led down to the coast, Hennessy heard a slow "flapping" and looked up to see a "very big" creature with a "horn" at the back of its head. There was "not a feather in sight."

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L

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Pterosaur
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A life-sized restoration of the South American tapejarid pterosaur Tapejara imperator is now on display at the Karlsruhe Museum fur Naturkunde. This remarkable pterosaur was named by Diogenes de Campos and Alex Kellner in 1997 and is famous for its immense sail-like crest, supported anteriorly by a tall vertical spine. A new generic name for this taxon is in press and due to be published soon.

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L

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RE: Giant Pterosaur
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UK scientists say they have solved the mystery of why prehistoric flying reptiles grew crests on their heads.

A rare skull specimen found in Brazil shows the crest appeared at puberty, suggesting it was used to attract attention from the opposite sex.
University of Portsmouth experts say pterosaurs, which ruled the air during the time of the dinosaurs, flaunted their headgear in sexual displays.
The findings are published in the journal Palaeontology.
Palaeobiologist Dr Darren Naish said the crest was a signal of sexual maturity; used like a pea****'s tail to attract a mate.

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The giant reptiles that flew above the earth until about 65 million years ago could have grown to twice the size originally thought with wingspans of at least 18 meters, a palaeontologist said on Thursday.
That would be roughly five times bigger than an albatross, which ranks among the birds with the largest wingspans in the modern world.

Dr David Martill of the University of Portsmouth in southern England, said his research on pterosaur wings appeared to solve the problem of how such enormous creatures managed to take to the skies and stay there.
Recent fossil finds in Mexico and Israel added weight to the theory that this prehistoric, flying reptile, which became extinct at the same time as the dinosaurs, could have been much bigger than many had realized.

"We haven't officially announced this yet but it might have been two times bigger" he told journalists at the British Association for the Advancement of Science's annual festival in Dublin.

Martill said fellow academic and collaborator Dr Eberhard "Dino" Frey of the Natural History museum in Karlsruhe, Germany, had recently found distinctive fossilized footprints in Mexico pointing to a creature with a wingspan "in excess of 18 meters."

"Even though they are just fragments they are bloody big fragments. We also have finger bones with really rather magnificent diameters."
Despite its size, Martill believes his studies of the bone structure and tissue of a pterosaur wing show it could have flown "really rather elegantly".

"The wing membrane is really very, very thin," he said, adding that the samples were about half a millimetre thick. "One of the other things we found out that was excitingly new was a very different shoulder joint".

The elaborate structure of the wing, more like that of a bat than a bird, combined with hollow bones and a body not much bigger than a human torso would have kept weight to a minimum.

"One imagines that the take off problems were less ... particularly if you add the fact that they were very, very lightly constructed to this enormous wing membrane area".

Martill said he had established that the wing was locked into the bottom of the body rather than the top, providing a greater surface area to benefit from the thermal air currents that give lift during flight.
More cumbersome would have been the neck, stretching to three meters in length and attached to a skull that could have added an additional two meters. Although not very aerodynamic, it might have allowed the pterosaur to pick up prey from the sea without flying dangerously close.

As for why they grew so big, it could have been a function of age: "One of the reasons might be that they just kept on growing," rather than reaching an adult size when growth stops.

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