Which epoch is known for having the first early primate ancestors?

The Paleocene epoch is recognized for being the initial period during which the first early primate ancestors emerged. This epoch lasted from about 66 to 56 million years ago and followed the extinction of the dinosaurs. It is significant because it marked the evolutionary beginnings of mammals adapting to new ecological niches following this mass extinction.

During the Paleocene, there was a diversification of mammals, which resulted in the development of primate-like mammals, often referred to as "plesiadapiforms." These early ancestors exhibit characteristics that hint at later primate traits, such as adaptations conducive to tree-dwelling. This evolutionary groundwork set the stage for the more recognized primates that appeared in subsequent epochs.

The Eocene, while also crucial in primate evolution, comes after the Paleocene and is more noted for the emergence of true primates rather than their most primitive ancestors. The Oligocene further developed primate evolutionary branches, leading to more modern forms, and the Holocene is a much more recent epoch that deals with human evolution and societal development, thus is not relevant to the origins of early primate ancestors.