Final answer:
Early fossil anthropoids are most notably documented from the Oligocene epoch, with key finds like the Fayum primates and Miocene epoch apes such as Proconsul and Sivapithecus, leading to knowledge about early hominins including Sahelanthropus tchadensis and Ardipithecus.
Step-by-step explanation:
Early fossil anthropoids are best known from the Oligocene epoch. Evidence of the earliest known anthropoids comes from sites like the Fayum in Egypt, where two main groups of primates were identified: Parapithecoidea and Propliopithecoidea. These groups are believed to represent the early forms of New World and Old World monkeys, respectively. Additionally, the Miocene epoch is key for understanding the rise of early apes, including the species Proconsul and Sivapithecus. The latter's fossils were widespread across Asia and exhibited similarities to modern orangutans. Very early hominins, such as Sahelanthropus tchadensis and Ardipithecus, also provided crucial information about primate evolution. Sahelanthropus was around at the time of the human-chimpanzee divergence, while Ardipithecus showed evidence of bipedality, deepening our understanding of human ancestry.