"Longipteryx is one of my favorite fossil birds, because it's just so weird— it has this long skull, and teeth only at the tip of its beak," says Jingmai O'Connor, associate curator of fossil ...

Humans do not have tails, but do we have “what it takes” for a tail? Hens don’t have teeth, but they have the genes for it. With atavism, it is as if our genomes serve as archives of our ...