282 Evolution? The Fossils Say YES!
only transitional dinosaur-bird fossil, it would be sufficient, but it is not alone any more.
An amazing array of new transitional bird fossils and feathered nonbird dinosaurs have
been discovered and described (figs. 12.1, 12.6, 12.10, and 12.11) that fill in most of the gaps
between theropods and advanced birds, so now we have a wealth of transitional forms, of
which Archaeopteryx is just one link.
The most earth-shaking discoveries come from the famous Lower Cretaceous Liaon-
ing fossil beds of China, which have now become one of the world’s most important fossil
deposits. These delicate lake shales preserve extraordinary features in fossils, including body
outlines, feathers, and fur, as well as complete articulated skeletons with not a single bone
missing. In the past 20 years, a major new discovery has been announced from these deposits
every few months, and almost all previous ideas about birds and dinosaurs were quickly
rendered obsolete by these discoveries (for a summary, see Norell 2005). The most amazing
fossils of all were a number of clearly nonflying, nonavian dinosaurs with well-developed
FIGURE 12.10. Meilong, a feathered dinosaur from the Liaoning beds that is preserved as an extraordinary
three-dimensional specimen coiled up in a sleeping position. (Courtesy M. Ellison and M. Norell, American
Museum of Natural History)