The Miocene is a geological epoch of the Neogene period and extends from about 23.03 to 5.33 Ma. The Miocene was named by Sir Charles Lyell. Its name comes from the Greek words meiōn, “less” and kainos, “new” and means "less recent" because it has 18% fewer modern sea invertebrates than the Pliocene. The Miocene follows the Oligocene Epoch and is followed by the Pliocene Epoch. The Miocene is the first epoch of the Neogene Period.
The earth went from the Oligocene epoch through the Miocene and into the Pliocene as it cooled into a series of Ice Ages. The Miocene boundaries are not marked by a single distinct global event but consist rather of regional boundaries between the warmer Oligocene and the cooler Pliocene.
The plants and animals of the Miocene were fairly modern. Mammals and birds were well-established. Whales, seals, and kelp spread.