Rare skull sparks human evolution controversy

Fragments of humans' ancient relatives are scattered across the globe. Sometimes a tooth or a few bones are all we have to tell us about an entire species closely related to humans that lived thousands or millions of years ago.

So when anyone finds a complete skull of a possible human ancestor, paleoanthropologists rejoice. But with new knowledge comes new controversy over a fossil's place in our species' very fuzzy family tree.

In the eastern European nation of Georgia, a group of researchers has excavated a 1.8 million-year-old skull of an ancient human relative, whose only name right now is Skull 5. They report their findings in the journal Science, and say it belongs to our genus, called Homo.

"This is most complete early Homo skull ever found in the world," said lead study author David Lordkipanidze, researcher at the Georgian National Museum in Tbilisi.

Humanoid skull discovered that dates back 1.8 million years sparks controversy.