Final answer:
The Fayum site in Egypt houses a rich record of fossil primates that are dated to the d. Oligocene epoch, which spanned from about 34 to 22 million years ago.
Step-by-step explanation:
The Fayum has a rich record of fossil primates dated to the Oligocene epoch. The Oligocene stretches from about 34 million years ago (MYA) to 22 MYA. It is during this time that we find the first indications of fossil monkeys at the Fayum site, near Cairo, Egypt. The primates found there are grouped into two main categories: Parapithecoidea and Propliopithecoidea, which are believed to be the ancestors of New World and Old World monkeys, respectively. Key to identifying these primates are their teeth and the dental formulas they exhibit, particularly the presence of a third premolar in their jaws.