Archaeopteryx has long been placed at the base of the bird evolutionary tree. It has traits that have helped to define what it is to be a bird, such as long and robust forelimbs. Yet in recent years, the discoveries of numerous small, feathery dinosaurs have created a conundrum for palaeontologists, raising questions about which animals are the ancestors of modern birds and which are just closely related cousins.作者:
寒武紀 時間: 2019-4-22 01:32 PM
