Denton does not say what the origin of birds may be; what he says and provides evidence for is that they could not have descended from dinosaurs because of the uniqueness of the feather and the lung. Here, in his own words, is a summary of his opinion concerning the feather:
"It is true that basically a feather is inded a frayed scale - a mass of keratin filaments - but the filaments are not a random tangle but are ordered in an amazingly complex way to achieve the tightly intertwined structure of the feather. Take away the exquisite coadaptation of the components, take away the coadaptation of hooks and barbules, take away the pricisely parallel arrangement of the barbs on the shaft and all that is left is a soft pliable structure utterly unsuitable to form the basis of a stiff impervious aerofoil. The stiff impervious property of the feather which makes it so beautiful an adaptation for flight, depends basically on such a highly involved system of coadapted components that it seems impossible that any transitional feather-like structure could posses even to a slight degree the crucial properties.'" (Evolution: A Theory in Crisis, p.209)
