Kenyanthropus - Dig Sites

Dig Sites

In 1999, Meave Leakey led an expedition in Kenya to dig for fossils, the second such expedition in the area. The first expedition was in 1998. They began to dig at a site that had yielded many other prominent hominin fossil specimens, Lake Turkana, which is located in the Kenyan Rift Valley and partially extends into southern Ethiopia. A member of the team, Justus Erus, discovered a skull in the Nachukui Formation at Lomekwi, an area of specific geology right next to the lake. The total number of fossils recovered from both expeditions at the dig sites included a temporal bone, three partial mandibles, two partial maxillae, and forty four teeth, but it was the skull dubbed KNM-WT 40000 that sparked the most scientific interest because of its relative completeness (Leakey 2001). This skull had many characteristics that had been seen before in other specimens, however the combination of features had never been seen before; that is when scientists realized that this was indeed a separate and unique species from any that had been previously discovered.

KNM-WT 40000 and the other bones were collected from a dark mudstone, which contained volcanic pebbles and solidified CaCO₃. The mudstone was located in between the Lokochot Tuff and the Tulu Bor Tuff. Beneath the Lokochot Tuff were the Moiti Tuff and the Topernawi Tuff. The KNM-WT 40000 specimen was dated at 3.5 million years, with the bed dated at 3.53 million years. Directly beneath the bed was the KNM-WT 38341 specimen, which was dated at 3.53 million years. Other specimens from various localities that were found above the b-Tulu Bor Tuff were dated at around 3.3 million years. The location of the mudstone was near a shallow lake, suggesting that the hominins lived near rivers or lakes.