The XO Directory

Hardly week goes by without a major archaeological discovery or the publication of a radical new theory about the human past. Reducing a year's worth of these stories to the 10 most important was a tall order, especially since our intent was to go beyond the headlines and select those we thought made a significant impact on the field--ones that will be talked about for decades.

With that in mind, here are our picks for the 2007's most important finds...