Richard Potts of the National Museum of Natural History in Washington, D.C., and his colleagues found 11 fragments of a single hominid skull during excavations at an archaeological site in Olorgesailie, Kenya. Together these finds mark the first discovery of ancient human bone at the site since exploration began in 1942. Based on radiometric dating and sedimentary evidence, the team estimates that the fossil is between 900,000 and 970,000 years old. The skull is from an adult or near-adult and shares some features with H. erectus. If it is a member of this species, it is a very petite representative. The researchers note that it is the smallest individual yet known from the time interval spanning 1.7 million and half a million years ago. Because many of the tools recovered from the same site are large and would have required significant strength and size to handle, Potts and his collaborators conclude that there was wide physical variation in the population to which this hominid belonged, with both large and small individuals present.
Other researchers interpret the new find differently, however. [The skull] doesn't look like anything else we know so far, contends Jeffrey H. Schwartz of the University of Pittsburgh, who penned an accompanying commentary in Science. He argues that a number of the fossils categorized as H. erectus show too much variation from the original, or type, H. erectus skull discovered in the late 19th century in Java to be considered members of the same species.