It was the absence of feathers that got conservation biologist Thor Hanson thinking about the significance of them. Hanson was in Kenya studying the feeding habits of vultures, and he noticed the ...

One of the remarkable abilities that birds possess is their ability to regenerate the feathers that they shed. Unlike human hair and nails, feathers consist of keratin and do not heal once damaged.

Thor Hanson's own cast of Archaeopteryx lithographica presents what he calls the "ancient wing written in stone." It was the absence of feathers that got conservation biologist Thor Hanson thinking ...