Orrorin tugenensis, nicknamed "millenium man" by its discoverers Martin Pickford and Brigitte Senut, was found in 2000 in the Lukeino Formation in Baringo, Kenya is the next oldest fossil find that is a possible hominin, at 6 million years old. The finds include femur and humerus fragments, along with some teeth and jaw fragments.
Pickford and Senut believed that Orrorin belongs in the the hominin clade due to its large size (much larger than expected for miocene apes), a suite of postcranial characters that indicate it was a biped, including femurs that are very similar to those of the Homo genus, and its small teeth with thick enamel, which is also similar to the teeth of Homo.
Some of the features that indicate that Orrorin does not belong in the hominin clade include its large, apelike canines. Also, there is not enough evidence to prove that it was bipedal, so more fossils will have to be found to prove that Orrorin is indeed a hominin.
