Final answer:
The earliest monkeys in the fossil record date back to the Oligocene epoch, starting around 34 MYA, with notable fossils found at the Fayum site in Egypt the Fayum primates are divided into groups that represent the earliest New World and Old-World monkeys.
Step-by-step explanation:
The earliest monkeys in the fossil record are from the Oligocene epoch, which began approximately 34 million years ago (MYA) and ended about 22 MYA. The most notable fossils of these earliest primates were found at the Fayum archaeological site in Egypt. There are two main groups of these Fayum primates: Parapithecid and Propliopithecoidea, which are believed to be the earliest New World and Old-World monkeys, respectively. The presence of a third premolar in Propliopithecus suggests they represent the earliest New World monkeys, despite first evolving in Africa. Similarly, the fossil monkeys with a dental formula of 2.1.2.3 found in propliopithecoids are interpreted as the earliest catarrhine primates, which share this trait with all Old-World monkeys and apes, including humans.