China hosts 20 million years of early Cretaceous era fossils, including amazingly detailed fossils of feathered dinosaurs, like the Sinosauropteryx, which sported short, bristle-like feathers.
Until this century, relative dating was the only technique for identifying the age of a truly ancient object. By examining the object's relation to layers of deposits in the area, and by comparing the object to others found at the site, archaeologists can estimate when the object arrived at the site. Though still heavily used, relative dating is now augmented by several modern dating techniques.
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