Hominid skull. This is the skull of a Paranthropus boisei, a species of early human estimated to have lived 2.6-1.3 million years ago. This example is the skull of an adult male. It has the facial and cranial features typical of the species, such as widely flaring cheek bones and forward projecting facial bones. This specimen is known as KNM ER 406 and it is 1.7 million years old. It was discovered in 1969 in Koobi Fora, Kenya.