標題: Small bird fills big fossil gap [打印本頁] 作者:
oviraptor 時間: 2015-6-3 09:26 PM 標題: Small bird fills big fossil gap
Reconstruction of the Cretaceous fossil bird from the Araripe Basin, Brazil. Illustration by Deverson Pepi
Archaeologists have stumbled upon a bird fossil that is so well preserved its long tail feathers have possibly retained their original color and spots. It’s a first-of-a-kind discovery for South America, and the oldest known bird ever found in Brazil.
The discovery was made in the Araripe Basin in Northeastern Brazil, where a former lakebed holds thousands of fossils from the Cretaceous period — 145 to 66 million years. At the time, Brazil and the rest of South America were in the process of separating from Gondwana — an ancient supercontinent that comprised Africa, South America, Australia, Antarctica, the Indian subcontinent and the Arabian Peninsula.
Location map of the discovery (red star) of the 115 million years old Brazilian fossil bird. Picture by Ismar Carvalho
115 million year old Cretaceous rocks where the oldest complete bird from Gondwana was found. Photo by Ismar Carvalho.
On the very rare occasions that scientists uncover Cretaceous birds fossils, the specimens tend to be well-preserved. However until now, the best specimens have primarily been found in China and in the form of 2-D slabs.
This newly discovered, 115-million-year-old fossil retains its 3D shape, revealing a hummingbird-sized animal with long ribbon-like tail feathers. The tail feather are 30 percent longer than the length of the main skeleton and boast a row of five spots — possible remnants of its original plumage — at the base of the bird’s backside.
The oldest bird from Brazil, found in rocks of 115 million years old. Photo by Ismar Carvalho.
