Little Foot, a fossilized Australopithecus Prometheus, an early hominid, has been dated as 3.67 million years old—making it an older relative of the famous 3.2 million-year-old Australopithecus, Lucy. Researchers used a dating method that measures isotopes in rock created by exposure to cosmic rays—the ratio of isotopes reveal how long the rock has been underground. The researchers say that the discovery lends evidence to the idea that there were multiple species of Australopithecus present in Africa at this time.

Read more