June 25, 2004

Hominin browridge from AD5/7-1. The morning began with the entire crew going to AD5/7-1. That's our code for the name of the site where our team found an early human fossil last season. As you can see in the photos, it's a complete brow ridge and nearly-complete temporal bone (ear region) of a skull, dated about 900,000 years old. During 6 weeks of really careful digging and sieving, we also found nine fragments of the brain case. I talked with the crew about last year's work, and about the paper written by our scientific team. I passed around a copy, and they wondered about all the technical jargon and complicated table of measurements. But they recognized that the geological drawings, the list of other fossil animals known from that time period, and the photos of the partial skull were the result of our many years of hard work together. It took me a little by surprise when they all spontaneously applauded, out there on the slope of ancient outcrop.

Hominin temporal bone from AD5/7-1. Most of our work involves looking for the stone-tool clues of the behavior of these hominins, as we call them. These are the early people who made the Olorgesailie handaxes and other early tools. We're especially interested in putting these human ancestors in a larger framework. We do this by uncovering clues about the surroundings in which they lived and the survival challenges to which they had to adapt. Stone tools, fossil animals, geological evidence of old habitats - finding these things has been a big motivation of our work over the past 18 years at Olorgesailie. Yet it's very special, inspiring, something of an emotional discovery to actually see a portion of an individual who lived at the time, who had made one of the handaxes you yourself have excavated and touched for the first time in nearly a million years.

Rick talks to the field crew. We left several of the crew at AD5/7-1 to begin brushing the outcrop and getting the site ready for more excavation. The rest of us went to Site 15, the place where we found an elephant butchery site some years ago. We continue to excavate this site because we keep finding more almost every season. For example, a few years ago, we found that an antelope butchery site lay right next to the elephant butchery. Last year, right at the end of the season, there were clues that the handaxe-makers had also eaten from a zebra close by. All of this happened about 990,000 years ago, which is the geologic age of one of the old soils here.

So we marked out an area of new excavation at Site 15. Will we find a place where early humans butchered a zebra? What else might we find in this spot, which has been buried for such a long time? We'll tell you about this over the next few weeks as the excavations develop