| Species: | Paranthropus boisei |
| Age: | 1.7 million years |
| Date of Discovery: | 1969 |
| Location: | Koobi Fora, Kenya |
| Discovered by: | Richard Leakey and H. Mutua |
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KNM ER 406 is a nearly complete adult male Paranthropus boisei. It has the facial and cranial features typical of the species, such as the widely flaring zygomatic arches with a forward placed connection to the other facial bones, giving it a "dish-shaped" face. Also, there are the prominent sagittal and nuchal crests, and the massive cheek teeth.
The cranial capacity of ER 406 has been estimated at 510cc.
Of additional interest is the fact that ER 406 displays evidence of what may possibly be a metastatic abcess (infection of the bone tissue). Bone disease is nearly absent from the early human fossil record, but ER 406 has a circular hole just behind the left orbit on the frontal bone (visible in the enhanced photograph on the bottom -- arrow) measuring 1.2cm in diameter.
