|
The dinosaur renaissance〔The term has entered into common usage after an article of the same name by paleontologist Robert T. Bakker in ''Scientific American'', in April 1975. Examples can be found (here ) and (here ).〕 was a small-scale scientific revolution that started in the late 1960s, and led to renewed academic and popular interest in dinosaurs. It was sparked by new discoveries and research indicating that dinosaurs may have been active and warm-blooded animals, rather than cold-blooded and sluggish as had been the prevailing view and description during the first half of the twentieth century. The new view of dinosaurs was championed by John Ostrom, who argued that birds evolved from coelurosaurian dinosaurs, and particularly Robert Bakker who argued passionately that dinosaurs were warm-blooded in a way similar to modern mammals and birds. Bakker frequently portrayed his ideas as a renaissance of those popular in the late nineteenth century, referring to the period in between the Dinosaur Wars and the dinosaur renaissance as "the dinosaur doldrums".〔 The dinosaur renaissance led to a profound shift in thinking on nearly all aspects of dinosaur biology, including physiology, evolution, behaviour, ecology and extinction. It also led to many depictions of dinosaurs in popular culture. == Dinosaurs and the origin of birds == In the mid and latter parts of the nineteenth century, many scientists thought there was a close relationship between birds and dinosaurs—and that dinosaurs represented an intermediate stage between "reptiles" and birds. Shortly after the 1859 publication of Charles Darwin's ''The Origin of Species'', British biologist and evolution-defender Thomas Henry Huxley proposed that birds were descendants of dinosaurs. He cited skeletal similarities, particularly among dinosaurs, the "first bird"—''Archaeopteryx''—and modern birds. However, in 1926, Gerhard Heilmann wrote his influential book ''The Origin of Birds'',〔Heilmann, G. 1926: ''The Origin of Birds''. Witherby, London. ISBN 0-486-22784-7 (1972 Dover reprint)〕 in which he dismissed the dinosaur–bird link, based on the dinosaurs' supposed lack of a furcula (fused clavicles).〔An assumption which is now known to have been incorrect.〕 Thereafter, the accepted hypothesis was that birds evolved from 'crocodylomorph' and 'thecodont' ancestors, rather than from dinosaurs. This removed dinosaurs from a central role in debates about the origin of living species, and may have contributed to the decline of academic interest in dinosaur evolution. This situation persisted until 1964, when John Ostrom discovered a small carnivorous dinosaur which he named ''Deinonychus antirrhopus'', a theropod whose skeletal resemblance to birds seemed unmistakable. This led Ostrom to argue that Huxley had been right, and that birds had indeed evolved from dinosaurs.〔 Although it was ''Deinonychus'' that inspired Ostrom to connect birds with dinosaurs, very similar birdlike dinosaurs, such as ''Velociraptor'', had been known for many decades, but no connection had been made. After Ostrom's discoveries, the idea that birds evolved from dinosaurs gained support among palaeontologists, and today it is almost universally accepted. Newer methods, such as cladistics, and the discovery of several feathered dinosaurs have helped confirm the relationship. The relationship between dinosaurs and birds has led to considerable interest in dinosaur—particularly theropod—phylogeny, which is now far better understood. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Dinosaur renaissance」の詳細全文を読む スポンサード リンク
|