Une découverte fondamentale sur la respiration des oiseaux

Researchers at Oregon State University have made a fundamental new discovery about how birds breathe and have a lung capacity that allows for flight – and the finding means it’s unlikely that birds descended from any known theropod dinosaurs.
This study has been published in 2009 in The Journal of Morphology. It’s been known for decades that the femur of birds is largely fixed: what was just discovered, however, is that it’s this fixed position of bird bones and musculature that keeps their air-sac lung from collapsing when the bird inhales.
However, every other animal that has walked on land, including dinosaurs, has a moveable thigh bone that is involved in their motion. The implication is that birds almost certainly did not descend from theropod dinosaurs, such as tyrannosaurus or allosaurus. The findings add to a growing body of evidence in the past two decades that challenge some of the most widely-held beliefs about animal evolution.