15 décembre 2016

Queue de dinosaure préservée dans l'ambre


Absolument extraordinaire.

Renversant.

Un bout de queue de dinosaure, vieux de 99 millions d'années, préservé dans l'ambre! Et couverte de plumes! Qui ressemblent à des plumes d'émeu!

Je capote.

La nouvelle et les images sont ici et ici. En voici un extrait:

The tail of a 99-million-year-old dinosaur, including bones, soft tissue, and even feathers, has been found preserved in amber

(...) The semitranslucent mid-Cretaceous amber sample, roughly the size and shape of a dried apricot, captures one of the earliest moments of differentiation between the feathers of birds of flight and the feathers of dinosaurs. (Learn more about the evolutionary relationship between dinosaurs and birds.)

Inside the lump of resin is a 1.4-inch appendage covered in delicate feathers, described as chestnut brown with a pale or white underside.

CT scans and microscopic analysis of the sample revealed eight vertebrae from the middle or end of a long, thin tail that may have been originally made up of more than 25 vertebrae.

Based on the structure of the tail, researchers believe it belongs to a juvenile coelurosaur, part of a group of theropod dinosaurs that includes everything from tyrannosaurs to modern birds.

The presence of articulated tail vertebrae in the sample enabled researchers to rule out the possibility that the feathers belonged to a prehistoric bird. Modern birds and their closest Cretaceous ancestors feature a set of fused tail vertebrae called a pygostyle that enables tail feathers to move as a single unit.






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