標題: Eoconfuciusornis [打印本頁]
Dinosaurprince 時間: 2009-1-4 03:12 PM 標題: Eoconfuciusornis
Scientific name : Eoconfuciusornis Zheungi
Family : Confuciusornithae
Period : Early Cretaceous (131 Mya)
Location : China
The bird discovered recently in China, the fatherland of feathered dinosaurs and primitive birds. The first fossil found is nearly well perserved, missing only the tup of its tail. The length of the bird is about 40 cm while the feathered tail occupied 22 cm. It is lying lively in a yellowish stone forever, recording a remarkable history of bird evolution.
Eoconfuciusornis Zheungi , connected the missing link between Archeaopteryx ( Late Jurassic 150 Mya ) and more evolved birds encountered in China. This site has provided a prove of bird and small dinosaur fossils that have significantly boosted our knowledge of bird evolution, but the remains have come all from 125 to 120 Ma ago, which the time gap may too narrow for the birds' evolution. The Archaeopteryx lived about 150 Ma ago, thus a 25 Ma gap existed between it and Yixina birds. Eoconfuciusornis, found in the Dabeigou formation, fills in this gap, as it lived 131 Ma ago.The discovery is described in the Chinese Jonaral 'Science'.
"The new discovery gives us a span of 11 million years of history for the Confuciusornis family, long enough to show patterns of evolution. Archaeopteryx was an efficient powered flapping flyer, but lacked many of the adaptations of the skeleton seen in modern birds – especially fusions of bones that support flight muscle and reduce length of the tail," Mike Benton of the University of Bristol, UK, co-author of a description of Eoconfuciusornis with paleontologists from the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) in Beijing, told NewScientist.
Confuciusornis was already well adapted to flight, with flight muscles attached on the wing via a large bone ridge called the deltopectoral crest, and on the body by a well developed fused sternum.
Eoconfuciusornis had a pair of distinct sternal plates and smaller deltopectoral crest, mixing Confuciusornis traits with more archaic ones like the ones found in Archaeopteryx, a fact that revealed it as the earliest known member of the Confuciusornis family, Confuciusornithidae.Notwithst anding to become the first bird without teeth, they still retained many primitive traits and were a dead evolutionary branch, leaving no descendants. Later toothed birds had more advanced traits resembling modern birds, thus modern birds lost their teeth independently
c7 時間: 2009-1-4 08:57 PM
達爾文 時間: 2009-1-5 10:05 PM
Dinosaurprince 時間: 2009-1-10 08:27 AM
oviraptor 時間: 2009-1-10 09:07 PM
達爾文 時間: 2009-1-11 01:49 AM
原帖由 Dinosaurprince 於 2009-1-10 08:27 AM 發表古生物學上分類包括所有權威的書籍看看那裡有人把鳥類當作是恐龍類，兩棲類跟恐龍(爬行類)關係都很密切，能道兩棲類都是恐龍嗎?
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