How giant pterosaurs ruled the air

 作者:毋丘估鲣     |      日期:2019-03-09 03:01:01
NOW we know how pterosaurs could once rule the skies. The biggest animals ever to fly had super-efficient bird-like lungs. Leathery-winged pterosaurs evolved 220 million years ago from the same group of reptiles that gave rise to crocodiles and, later, birds. How the animals with 10-metre wingspans powered their flight had been a mystery because they were thought to have inflexible ribcages, which would have made their breathing too inefficient for such exertion. Leon Claessens at the College of the Holy Cross in Worcester, Massachusetts,