> "We can be sure of the source because the vertebrae are not fused into a rod or pygostyle as in modern birds and their closest relatives," he explained. For

> "We can be sure of the source because the vertebrae are not fused into a rod or pygostyle as in modern birds and their closest relatives," he explained. For non-experts (like me) I think it comes as a surprise to learn just how rudimentary these people's techniques are.