Final answer:
Sahelanthropus tchadensis was discovered by French paleoanthropologist Michel Brunet and his team in Chad in West Africa in 2001-2002. It is the oldest of the three species and has been dated to nearly seven million years ago. The discovery of Sahelanthropus tchadensis is significant because it provides insights into the evolutionary history of humans and chimpanzees.
Step-by-step explanation:
Sahelanthropus tchadensis was discovered by French paleoanthropologist Michel Brunet and his team in Chad in West Africa in 2001-2002. It is the oldest of the three species and has been dated to nearly seven million years ago. The discovery of Sahelanthropus tchadensis is significant because it provides insights into the evolutionary history of humans and chimpanzees.