An Ancient Relative?

Scientist Meave Leakey examines the skull she discovered of a likely human ancestor.

The human family tree may have more branches than we once thought. A study released last week says ancient bones discovered in northern Kenya are closely related to humans. A 3.5 million-year-old skull discovered in a dry riverbed has a large flat face and small teeth, features that are very human-like. Scientists are calling the new species Kenyanthropus platyops, which means "Kenyan flat-face."

Until now, the oldest fossil believed to be a human ancestor was a skeleton found in Africa in 1974 and nicknamed Lucy. This apelike creature, which walked on two legs, belongs to the species Australopithecus afarensis.

A reconstruction of Lucy and her mate shows they looked more like modern apes than like humans.

The new, more human-looking fossil dates from around Lucy's time. This suggests that modern humans could be descendants of at least two different species. "If you think of a family tree with a trunk, we're talking about two trunks," says Tim White, an anthropologist at the University of California, Berkeley.

The flat-face skull was discovered by famed paleontologist Meave Leakey. The riverbed spot where she found it is a gold mine of fossils. Leakey believes that her team of researchers will find a third possible ancestor to humans in the near future.