Primates originated during the Cenozoic era, specifically in the Paleocene epoch, which occurred from approximately 66 to 56 million years ago. The Cenozoic era is also known as the "Age of Mammals" and is the most recent geological era, following the Mesozoic era (which includes the age of dinosaurs) and the Paleozoic era.

Primates are a group of mammals that include humans, apes, monkeys, and prosimians (lemurs, tarsiers, and lorises). They are characterized by having forward-facing eyes, grasping hands and feet, and complex social behaviors. The origins of primates can be traced back to a common ancestor with other mammalian groups, which lived during the Mesozoic era.

The Cenozoic Era:
The Cenozoic era is divided into three major periods: the Paleogene, the Neogene, and the Quaternary. The Paleogene period includes the Paleocene, Eocene, and Oligocene epochs, while the Neogene period includes the Miocene and Pliocene epochs. The Quaternary period includes the Pleistocene and Holocene epochs, which extend to the present day.

Origin of Primates:
During the Paleocene epoch, after the extinction of the dinosaurs, the Earth's climate started to change and become more favorable for the diversification of mammals. The Paleocene is when the first true primates emerged. These early primates were small, arboreal (tree-dwelling) mammals with adaptations such as grasping hands and feet, forward-facing eyes, and an increased reliance on vision.

The earliest primates were likely insectivorous, feeding on insects and other small invertebrates. Over time, primates diversified and evolved different adaptations, such as larger brains, increased social complexity, and varied diets. This led to the emergence of different primate groups, including prosimians, monkeys, apes, and eventually humans.

Conclusion:
In conclusion, primates originated during the Cenozoic era, specifically in the Paleocene epoch. This era is often referred to as the "Age of Mammals" and marks the diversification and evolution of many mammalian groups, including primates. The Paleocene epoch was a crucial period for the emergence and early evolution of primates, setting the stage for the subsequent development of the primate lineage throughout the Cenozoic era.