Quel boulet , Hell

TCHOU THCOU *écrase ax avec son tain *

A rooster-sized dinosaur with a long, slender snout and wing-like limbs is forcing a rethink on bird evolution.

The 90 million-year-old reptile belongs to the same sickle-clawed group of dinosaurs as Velociraptor and feathered dinosaurs from China.

Buitreraptor gonzalezorum, from the Nequén Basin in central Argentina may provide tantalising evidence that powered flight evolved twice.

Details of the discovery appear in the academic journal Nature.

One theory suggests the lineage of dinosaurs the new animal belonged to, the dromaeosaurs, originated in the Cretaceous Period (144 to 65 million years ago).

But this discovery suggests their lineage can be traced further back in time, to the Jurassic (206 to 144 million years ago), experts say.

Continental movement

It would mean dromaeosaurs were around when the present-day continents of Earth were organised into a single landmass. This giant landmass later split into northern and southern parts, called Laurasia and Gondwana respectively.

Buitreraptor, Field Museum
The animal was about the size of a rooster
"The preservation of Buitreraptor is superb. The rich fauna of this area, known as La Buitrera, includes other carnivorous dinosaurs," said co-discoverer Sebastián Apesteguía of the Museum of Natural Sciences in Buenos Aires, Argentina.

These include Giganotosaurus, a 13-14m-long behemoth that is the largest known meat-eating dinosaur.

Until recently, the dinosaur group had only been found in Cretaceous rocks of Asia and North America, continents that were part of Laurasia.

The new discovery, named Buitreraptor, provides definitive evidence that dromaeosaurs also lived in South America - part of Gondwana.

They must have originated when all of the continents were still assembled in a single landmass - during the Jurassic. When the landmass split in two, the dromaeosaurs diverged into northern and southern groups.

Family rift

Analysis by the authors of the Nature paper show Buitreraptor and Rahonavis, a fossil animal from Madagascar previously considered a primitive bird, form a southern branch of the dromaeosaur family tree.

This branch is distinct from Laurasian dromaeosaurids, including Velociraptor and some of the famous feathered dinosaurs from China. Birds are commonly thought to have evolved from this group.

The authors say the discovery Rahonavis and Buitreraptor have long and wing-like forelimbs could imply that flight evolved twice, once in birds and once among this group of Gondwanan dromaeosaurs.

The specimen will be on show at the Chicago Field Museum´s Evolving Planet exhibition that opens in March.

Pour les connaisseurs

Goodbye

T´es cheuveux d´ébénes me font oublier ma peine
T´es yeux de jais me font chavirer tout entier
Et ton etre au complet n´est qu´a désirer^^

arretez de polluer la page

Axnyff

Tentine pipine tonton les roustion les couille a papa son collé au plafon

Bébé rocco sur sa moto faisait du 100 et du 0 , dans un putin de dérapage il ce la coinca dans l´embréyage ...

Salut!!

Moi je squattes à Juviscy
et toi tu creches à neuilly
notre rencontre c´était fatal
ça c´est passé dans les halles

Depuis je veut te revoir
que je suis au desespoir
j´ai même plaqué toutes mes meufs
toi tu m´fait un effet boeuf

Je sais pas comment te dire ce que je peut pas écrire , faudrait qu´j´invente des mots qu´existebnt pas dans le dico

C´est toi que je t´aime !!

vachement beaucoup

hell surveilles Dragon
Sur ce ,

bon je sur-chaffe trop la , tout le monde

Genial darkang

bye dragon

je saigne du nez !! !!

sa me dit tjrs pas qui je suis

Osef

Dragon n´oublie pas ta pillule

Darknyff mdr

Dragon c´est simple: t´es qui tu es et pas un autre qui serait nous

Bon , j´y vais les enfants