As early as 3.4 million years ago, some individuals with a taste for meat and marrow — presumably members of the species best known for the skeleton called Lucy — apparently butchered with sharp and heavy stones two large animals on the shore of a shallow lake in what is now Ethiopia.

Scientists who made the discovery could not have been more surprised. They said the cut marks on a fossilized rib and thighbone were unambiguous evidence that human ancestors were using stone tools and sometimes consuming meat at least 800,000 years earlier than previously established. The oldest confirmed stone tools are less than 2.6 million years old, perhaps only a little before the emergence of the genus Homo. [Read more...]