- noting or pertaining to an epoch of the Tertiary Period, occurring from 10 to 2 million years ago, and characterized by increased size and numbers of mammals, by the growth of mountains, and by global climatic cooling.
- the Pliocene Epoch or Series.
- of, denoting, or formed in the last epoch of the Tertiary period, which lasted for three million years, during which many modern mammals appeared
- the Pliocene epoch or rock series
