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An early human skull from Africa

Discovery site at Olorgesailie, Kenya. Large stones are visable from the lava ridge context. Image courtesy of Richard Potts.
Click here for a high resolution photograph.

The early humans that lived around 2 million to 500,000 years ago may have come in a wide variety of shapes and sizes. Scientists working in Kenya have discovered a fossil skull from a particularly small adult that lived approximately 930,000 years ago.

Scientists often disagree over whether the humans or "hominids" from this time period should be lumped into one species, Homo erectus, or split into several categories. (Modern-day hominids -- that's us -- belong to the species, Homo sapiens.) It's generally agreed that these early hominids had relatively large brains, walked on two legs, and made tools. But fossil specimens from this time period also differ from each other in smaller ways.

One reason for the disagreement is that researchers have found few African hominid fossils from the later part of this time period, around 1 million to 500,000 years ago. This gap has made it difficult for researchers to compare fossils from different regions.

Various specimens attributed to Homo erectus. The Trinil fossils (the H. erectus type specimen) and the Sangiran fossils represent the same species and show a wide range of individual variation. Image courtesy of Jeffrey Schwartz.
Click here for a high resolution photograph.

Richard Potts of the National Museum of Natural History and his colleagues now describe a small hominid skull from a site in Kenya where researchers have also found abundant handaxes. Many of the skull's features are similar to those of Homo erectus, but it also has its own unique set of traits. For example, it's quite small, even though it belonged to an adult.

The handaxes from the same spot, however, are quite large. Cutting the stone flakes that were used as blades was probably a job for a much larger individual. The authors suggest that both large and small adults were part of the same population. Other hominid fossils from Europe and Asia also support the idea that hominid appearances varied widely around this time.

Potts and his colleagues describe their discovery of the skull in the 02 July 2004 issue of the journal, Science.


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