[2] From 1971 to 1978, Martin Pickford had carried out extensive research in the Tugen Hills under a permit issued by the Kenyan Office of the President.
In 1974, Pickford found the first hominid fossil from the Lukeino Formation, a lower molar, which is included within the holotype of Orrorin tugenensis.
[6] A P4 discovered at the Lukeino Formation has been proposed to belong to an amphicyonid by Morales et al. (2016), as both its age and dimensions are similar to Bonisicyon.
[7] Until the mid-1990s, only a few partial remains of cercopithecoideans were known from the Lukeino Formation, and then after surveys were conducted from 1998 onwards by the Kenya Palaeontology Expedition led to the discovery of new material within the Aragai Member,[8] a site situated in the lower levels of the Lukeino Formation.
Most of the collection consists of craniodental specimens generally well-preserved in a hard matrix but there are three postcranial bones.