JVP

Dernière issue:

Andres, B. & Ji Q. 2006. A new species of *Istiodactylus* (Pterosauria, Pterodactyloidea) from the Lower Cretaceous of Liaoning, China. _Journal of Vertebrate Paleontology_ 26(1):70-78.

Abstract: "*Istiodactylus sinensis*, sp. nov., from the Jiufotang Formation of Liaoning, People's Republic of China, is described on the basis of a single nearly complete and nearly osteologically adult specimen. This is the tenth pterosaur described from this formation and the eighteenth pterosaur species described from northeastern China in almost half as many years. The species is placed in the Istiodactylidae, which was previously a monospecific family of pterodactyloid pterosaurs known only from the Isle of Wight, England. The new form is distinct from the two other istiodactylid species. It is smaller, more plesiomorphic, and younger than *Istiodactylus latidens*, but larger and more derived than the contemporaneous *Nurhachius ignaciobritoi*. *Istiodactylus sinensis* is very similar to *I. latidens*, so that almost all of the previous autapomorphies of *I. latidens* are now synapomorphies of *Istiodactylus*. They differ most in that *I. sinensis* is much smaller than *I. latidens*. The length of the wingspan, skull, and most of the preserved limb elements of *I.sinensis* are about 63 percent of the wingspan and elements of *I. latidens*. This new specimen demonstrates that *Istiodactylus* is diagnosed by, among other characters, a dorsoventrally depressed but not laterally expanded rostrum, and the presence of a suborbital vacuity. A dorsal deflection of the alveolar margins of the jaws and a humerus between 55 percent and one and a half times the length of metacarpal IV are synapomorphies uniting the Istiodactylidae and the Anhangueridae."

Gower, D. J. & S. J. Nesbitt. 2006. The braincase of *Arizonasaurus babbitti*.Further evidence for the non-monophyly of 'rauisuchian' archosaurs. Journal of Vertebrate Paleontology_ 26(1):79-87.

Abstract:"The braincase of the rauisuchian pseudosuchian archosaur *Arizonasaurus babbitti*, from the Middle Triassic of the western United States, is described from two specimens. There are no obvious braincase autapomorphies and most of the other braincase features of *A. babbitti* are plesiomorphic for pseudosuchians/crurotarsans. The results of phylogenetic analyses of archosaurian braincase characters indicate that *A. babbitti* is not especially closely related to other rauisuchians for which braincase anatomy is known (*Batrachotomus kupferzellensis*, *Saurosuchus galilei*, *Postosuchus kirkpatricki*, *Tikisuchus romeri*). Given that *A. babbitti* is a member of a clade that includes *Poposaurus* and chatterjeeids to the exclusion of most other rauisuchians, braincase data suggest that Rauisuchia are not monophyletic. This is in accordance with a recent appraisal of on-braincase data but, in contrast, our analyses suggest that *Poposaurus* and its closest allies are more distantly related to Crocodylomorpha than are other rauisuchians."

Harris, J. D. 2006. Cranial osteology of *Suuwassea emilieae* (Sauropoda: Diplodocoidea: Flagellicaudata) from the Upper Jurassic Morrison Formation of Montana, USA. _Journal of Vertebrate Paleontology_ 26(1):88-102.

Abstract: "Cranial elements of *Suuwassea emilieae* (Sauropoda: Diplodocoidea) from the Upper Jurassic Morrison Formation of Montana, U.S.A., represent one of only a few flagellicaudatan skulls known. Preserved elements include a left premaxilla, a fragment of right maxilla, a right squamosal, a right quadrate, a basicranium and skull roof lacking only the rostral end of the frontals, basipterygoid processes, and parasphenoid rostrum. Autapomorphic features of the skull include: premaxillary teeth projecting parallel to long axis of premaxilla; single optic nerve foramen; postparietal foramen present and larger than parietal foramen; supraoccipital with elongate ventral process contributing little to dorsal margin of foramen magnum; basioccipital not contributing to floor of median condylar incisure; and antotic processes with no dorsal contact with frontals. The basicranium more closely resembles that of *Apatosaurus* rather than *Diplodocus* and is also unlike the skull of *Dicraeosaurus*, despite its possession of a similar postparietal foramen, a feature unique among Morrison Formation sauropods. Pending reanalysis of *Tornieria africana*, which also possesses it, the postparietal foramen must be viewed as a symplesiomorphic retention in the Dicraeosauridae, with its loss a synapomorphy of the Diplodocidae, or at least of the North American members of the latter clade."

Goodwin, M. B., W. A. Clemens, J. R. Horner, & K. Padian. 2006. _Journal of Vertebrate Paleontology_ 26(1):109-112. The smallest known *Triceratops* skull: New observations on ceratopsid cranial anatomy and ontogeny. _Journal of Vertebrate Paleontology_ 26(1):103-112.

Abstract: "The discovery of the smallest *Triceratops* skull (UCMP 154452) provides a new ontogenetic end member for the earliest stage of ceratopsid (Centrosaurinae plus Chasmosaurinae) cranial development. The lack of co-ossification among the parietal, squamosals, postorbitals, quadratojugal arch, and the braincase preserves sutural contacts and bone surfaces that later become obscured in adults. The ability to document the early development and morphology of the horns and frill in Triceratops allows a reevaluation of their functional roles. UCMP 154452 shows that the cranial ornamentation of the frill and the postorbital horns were not restricted to adults, but began at an early age in this species. This evidence supports the hypothesis that the function of ceratopsid horns and frills was potentially important for visual communication and species recognition because in this young form it could not have functioned in sexual display. Although some features of UCMP 154452 anticipate or mimic the adult character states, some braincase characters recapitulate the juvenile and adult stages of more basal neoceratopsians."

Henderson, M. D. & J. E. Peterson. 2006. An azhdarchid pterosaur cervical vertebra from the Hell Creek Formation (Maastrichtian) of southeastern Montana. _Journal of Vertebrate Paleontology_26(1):192-195.

Rien de vraiment nouveau mais c'est déjà ça ...

On avait déjà parlé du petit Tricé sur Dinonews:

ouaip d'ailleur je 'adore celuici

moi aussi il est trop mimi. Moi j'aimerais commander la découverte d'un bébé mapu ou gigy à mon pote Currie.

pas très recent également mais pour ceux qui sont interessé par l histoire de nos chère reptiles sans pattes :lol!: :lol!: :lol!: :lol!: =

Snakes Evolved on Land, New Fossil Find Suggests
Nicholas Bakalar
for National Geographic News
April 19, 2006

An ancient snake with hips connected to its spine might be proof that slithery serpents originated on land, not in the water, a new fossil find reveals.

The fossil snake—which has a primitive pelvis and robust, functional legs outside the ribcage—dates from about 90 million years ago.Sebastian Apesteguía, a researcher with the Argentine Museum of Natural Science, says the new fossil is not the oldest snake fossil ever found. Older marine snakes have been unearthed in North Africa and Eastern Europe.

But the species, named Najash rionegrina, is the earliest limbed snake ever found in a fully terrestrial deposit, he says.

N. rionegrina was discovered in Argentina's Rio Negro province, about 700 miles (1,130 kilometers) southwest of Buenos Aires (see map).

Apesteguía and colleague Hussam Zaher, of the Zoological Museum of the University of São Paulo in Brazil, describe the find in tomorrow's issue of the journal Nature.

Land or Water?

Many living snakes, such as pythons, have the vestiges of legs that are not attached to the backbone and simply hang from the body. By contrast, Apesteguía said, "In Najash the hip was connected to the vertebrae, so it has a sacrum. No other known fossil or extant snake is so primitive as to retain this feature."

The sacrum is the bony structure that connects the spine to the hips in vertebrates, including humans.

The animal's sacral region would have made its legs well suited to digging or crawling, the researchers say, giving weight to a land-based origin for snakes.
Scientists who believe snakes evolved on land say they began as subterranean creatures.

Early snakes, the theory's supporters say, are closely related to scolecophidians, a living group of primitive land snakes that still have vestigial pelvic regions.But proponents of a watery origin believe that snakes most likely evolved from extinct marine reptiles called mosasaurs, powerful swimmers that spent their entire lives in the ocean. (Explore an interactive world of ancient sea monsters.)

"Snakes probably evolved during the Jurassic—150 million years ago," Apesteguía said, "but there are no fossils.

"During the early Cretaceous—120 million years ago—they exploded [into] several forms, including some terrestrial like Najash … " and some aquatic.

The fossil record shows that terrestrial and aquatic snakes both existed by the mid-Cretaceous—about 95 million years ago—leaving researchers unsure about which type evolved first.

The question, Apesteguía said, is, "Which is more primitive, the terrestrial Najash or the most primitive water snakes, a group called pachyophids?"

He points to evidence that marine snakes are less primitive: Their skull bones suggest that they could expand their mouths to ingest larger prey—a characteristic of modern snakes.

The marine snakes, Apesteguía concludes, "are ancient versions of modern snakes, not really primitive."

Making a Case

Olivier Rieppel is chair of the geology department at the Field Museum in Chicago, Illinois, and was not involved in the study.

He sees the find as convincing evidence that snakes originated on land.

"It's a most interesting fossil," he said. "It shows a character combination as would be expected in a snake that is [in the same classification as] all other known snakes.

"In that sense, it's a very important find from a critical period of the evolutionary history of snakes and in my mind settles the issue of a terrestrial origin of snakes."

S. Blair Hedges, an evolutionary biologist at Pennsylvania State University in University Park who was not involved in the study, says more fossils are needed to fully resolve the debate.

"But the discovery of this fossil snake with limbs from terrestrial sediments now swings the pendulum so far to the terrestrial [origins] camp that it will be hard for the advocates of the aquatic hypothesis—and I am sure they will still advocate it—to convince others in the community," he said.

et tenez une photo et un article lié au précédent(impressionnante la photos,pauvre crocodilien!)=

Photo in the News: Python Bursts After Eating Gator



October 6, 2005—Unfortunately for a 13-foot (4-meter) Burmese python in Florida's Everglades National Park, eating the enemy seems to have caused the voracious reptile to bust a gut—literally.

Wildlife researchers with the South Florida Natural Resources Center found the dead python last week after it apparently tried to digest a 6-foot-long (2-meter-long) American alligator. The mostly intact dead gator was found sticking out of a hole in the midsection of the python, and wads of gator skin were found in the snake's gastrointestinal tract.

The gruesome discovery suggests that the python's feisty last meal might have been too much for it to handle.

Clashes between alligators and pythons have been on the rise in the Everglades for the past 20 years. Unwanted pet snakes dumped in the swamp have thrived, and the Asian reptile is now a major competitor in the alligator's native ecosystem. (See "Huge, Freed Pet Pythons Invade Florida Everglades.")

"Clearly if [pythons] can kill an alligator, they can kill other species," Frank Mazzotti, a University of Florida wildlife professor, told the Associated Press. "There had been some hope that alligators can control Burmese pythons. … This [event] indicates to me it's going to be an even draw."

—Victoria Gilman

je vois pas trop ce que représente l'image la :confused:

un python qui vient de devorer un alligator après avoir lui aussi drépassé :lol!: :lol!: :lol!: :lol!:

ha ok gore ton truc :lol!: :lol!: :lol!: :lol!:

petite dedicasse a gigy(en fais tu parti?)=


Amateur dino fans can hunt with a pro



Judy Monchuk, The Canadian Press
Published: Monday, April 17, 2006
Article tools




CALGARY -- Dinosaur hunter Phil Currie is always looking for another piece of the prehistoric puzzle.

But the world-renowned paleontologist knows those potential windows into history don't necessarily have to be spotted by an expert.
Currie points to a 1997 group trek into Alberta's fossil-rich badlands to find a long-lost dinosaur quarry. The group not only located the amazing bone bed, but a host of other remains.

"Three major specimens came out of that tour just from people with us finding significant things," said Currie, an expert on meat-eating dinosaurs who teaches at the University of Alberta when he's not searching for fossils around the globe.

Skulls of a Cretaceous-era crocodile and a centrasaurus (a horned dinosaur like triceratops) were discovered, as was the partial skeleton of the gorgosaurus, a slightly built cousin of the mighty Tyrannosaurus rex.

"That was absolutely amazing," said Currie. "We haven't equalled that success yet, but that's what is possible. I think a lot of people don't realize that Alberta is one of the best places in the world for this."

Currie will lead 25 amateur paleontolgists on a four-day DinoTour in July that will include digging at the little-known quarry along the Red Deer River in Dry Island Buffalo Jump Provincial Park.

The site is virtually unknown to most Albertans. That's despite being the world's largest known bone bed for Albertosaurus, a fierce carnivore which was half the size of T. rex.

The quarry has yielded parts of 22 Albertosaurus skeletons and a growing understanding that the meat eaters travelled in packs.

"We can see a whole range of ages, from babies through to adults and that's really rare," said Currie. "That's not something that happens by coincidence, it's not like having an elephant's graveyard: dinosaurs just didn't do that. The fact that they're all together is an indication that they were all living together when they died."

Public fascination with dinosaurs has waned somewhat since reaching a frenzied pitch in 1993 with the release of the film Jurassic Park. But children have long been mesmerized by the mighty creatures, and the discovery of new dinosaur fossils, such as the "hidden dragon" ancestor of T. rex found in China, recently garnered headlines around the world.

That means casual tours like the July 21-24 one led by Currie and his wife Eva Koppelhus, a palynologist whose research has focused on prehistoric plants, are expected to fill quickly. Cost is $995 Cdn for adults and $795 for children aged nine to 17, which covers meals, accommodation, admission to the Dinosaur Park Field Station and the Royal Tyrrell Museum in Drumheller, Alta.

It's recommended for people who can comfortably hike five kilometres over rough terrain. Organizer Corliss Moore says the trip will generate a family memory to last a lifetime.

"Our tour visits a very beautiful part of Alberta and provides people with a great learning experience," said Moore, volunteer director of the Dinosaur Research Institute, which organizes the trek as a fundraiser to support fossil excavation.
And there's always that chance of changing history.

In 1987, 19-year-old Wendy Sloboda was a volunteer working with Currie and staff from the Royal Tyrrell when she discovered a nest of dinosaur eggs in Alberta's Dinosaur Provincial Park: the equivalent of striking paleontological gold. Five years later, as a Tyrrell staffer, Sloboda spotted North America's first bone bed of a pterosaur -- the 70-million-year-old flying reptile Quetzalcoatlus.

The popularity of science-based vacations done through museums and eco-tourism programs is growing.

"Clearly there's a need for this type of education and people appreciate it," said Currie. "They're willing to say 'Rather than spend my money sitting on a beach in Hawaii, I'm going to spend it doing this.' You learn something in the process and these people really do have fun."

Those looking for a more intense experience might want to look to the Gobi Desert, which has proven to be a treasure trove of dinosaur fossils. Once a wetland, the barren yet beautiful area has been the site of some of the most exciting finds of the last century, including the recently announced discovery of the T. rex ancestor which dates back to the Jurassic period. That's some 90 million years before its fearsome descendant was striking terror into other dinosaurs.

Currie, co-leader of a two-year expedition in the Gobi in the 1980s, is leading a 16-day tour in late August to Mongolia and will include several days where hardy adventurers will be able to prospect for dinosaur bones in the Gobi.

More information on the Alberta DinoTour can be found at www.dinosaurresearch.com.
© The Canadian Press 2006

lien très interessant a la fin(n est ce pas gigy?)

super quel bel hommage à mon pote. Génial. Tu es génial Phil. Je te l'avais déjà dit.
Le crâne au côté duquel il pose est celui qu'il a reconstitué pour et avec Coria et salgado c'est Giganotosaurus, car le maxillaire à des marges parallèles si vous regardez bien, ce qui n'est pas le cas de Mapusaurus.
ah si je pouvais le rejoindre! hummmm!

ah!si une majorité de paléontologues avait sa largesse d esprit et son intention de faire avancé et évoluer les moyens d investigations scientifiques,.............soupir!en france on a beaucoup de chose a apprendre,les anglais on déja une net avance sur nous!il faut que le milieux scientifique francais se tourne d avantage vers le public et ses passionnés.

oui qu'il publie déja quelque truc comme un mag francais sa serais trés bien et qu'il motive un peu et que l'état qubventionne les millieu scientifique beaucoup plus

Je vous l'ai déjà dit et je le répette, l'état ne peux pas subventionner des gens qui ne prosuisent pas de richesses.
Pour moi l'avenir est dans le privé.
je travaille pour une asbl, promotion du préhistosite, subventionnée par des moyens d'états car nous avons uns vocation de conservation de collections et une autre de communication, en dehors de cela on produit notre richesse nous même.
L'avenir est à la recherche privée et suventionnée par le privé.
Cf; Mapusaurus roseae en hommage à rose qui a gentiment subventionné deux années de fouilles.