Final answer:
Orrorin tugenensis was discovered in Kenya in 2001 by geologist Martin Pickford and paleontologist Brigitte Senut. This species, which exhibited traits indicative of bipedalism and dated to roughly 6 MYA, challenges the place of australopithicenes in the human lineage, potentially revising our understanding of early human evolution.
Step-by-step explanation:
The individual who discovered Orrorin tugenensis was Martine Pickford, a geologist from the Collège de France, alongside Brigitte Senut, a paleontologist from France's National Museum of Natural History. These two researchers found Orrorin tugenensis in Kenya in 2001. Dated to approximately 6 million years ago (MYA), Orrorin tugenensis exhibits anatomic traits suggestive of bipedalism, a key feature in hominin evolution.
Particularly, the size of the femoral head and the muscle attachments to the femur indicate that Orrorin was likely used to walking on two legs. Additionally, the teeth of Orrorin, with their thick dental enamel and small, square molars, align more closely with modern humans than with quadrupedal apes, further supporting Orrorin's classification as a hominin.
The discovery of Orrorin tugenensis is significant as it predates the australopithicenes. If confirmed to be a direct human ancestor, this could indicate that the australopithicenes may not be in our direct lineage. Ongoing exploration and additional fossils may illuminate the exact role of Orrorin in human evolution.