* Fossils are physical evidence of ancient life-from traces of animal activities to preserved body parts.
* When an animal dies, predators or scavengers usually eat its remains, or wind and rain destroy the fragile bones and tissues. But sometimes an animal's remains are quickly covered and protected by sediments-usually sand and silt carried by water and wind.
Reconstructing History
Ever since the first hominid fossil was identified in 1856, scientists have tried to reconstruct the faces of our ancient ancestors. But at first, scientists knew of only a few hominid fossils and had little knowledge of primate anatomy. As such, their reconstructions were largely speculative, though sometimes surprisingly accurate. Today, with an extensive fossil record and vastly improved techniques and technologies, scientists can re-create the faces of the past as never before.