Feather a dromaeosaurid found in the Yixian formation (124.6 MYA). Previously, a temporal paradox existed in the evolution of feathers—theropods with highly derived bird-like characteristics occurred at a later time than "Archaeopteryx"—suggesting that the descendants of birds arose before the ancestor. However, the discovery of "Anchiornis huxleyi" in the Late Jurassic Tiaojishan Formation (160 MYA) in western Liaoning in 2009 resolved this paradox. By predating "Archaeopteryx", "Anchiornis" proves the existence of a modernly feathered theropod ancestor, providing insight into the dinosaur-bird transition. The specimen shows distribution of large pennaceous feathers on the forelimbs and tail, implying that pennaceous feathers spread to
Feathers: The Evolution of a Natural Miracle "Archaeopteryx" fossil specimen and the resulting debate between English paleontologist Richard Owen, an opponent to evolution by natural selection, and Thomas Henry Huxley, an advocate for evolution. Hanson himself visits the Wyoming Dinosaur Center, a small museum in Thermopolis, Wyoming, which had acquired an "Archaeopteryx" specimen. Hanson interviews Richard Prum, the Coe Professor of Ornithology at Yale University, who proposed a developmental theory of feather evolution, which focuses "on how feathers grow and not worrying about what they're used for." Hanson also interviews Alan Feduccia, a professor at the University of North Carolina, who disagrees with the scientific consensus that