(Greek: a suffix; new, denotes certain "recent" eons when naming geological periods)

1. The epoch of geologic time, 55 million to 38 million years ago, during which the ancestors of many modern animals appeared.
2. Etymology: from Greek eos, "dawn" + Greek kainos, "new".
1. The third of the five major worldwide divisions (epochs) of the Tertiary period (Cenozoic era), extending from the end of the Eocene to the beginning of the Miocene period.
2. The rock strata formed during this epoch.
Of or belonging to the geologic time, rock series, or sedimentary deposits of the earlier of the two epochs of the Quaternary Period, characterized by the alternate appearance and recession of northern glaciation, the appearance and worldwide spread of hominids, and the extinction of numerous land mammals, such as the mammoths, mastodons, and saber-toothed tigers.

Almost all of the giant mammals, including woolly mammoths, giant wolves, giant ground sloths, and massive wombats disappeared at the end of the Pleistocene epoch and the start of the Holocene epoch.

A reference to the period also called Posttertiary or Glacial Period. Coined from Greek pleistos, "most" and kainos or cene, "new".

Of or belonging to the geologic time, rock series, or sedimentary deposits of the last epoch of the Tertiary Period, characterized by the appearance of distinctly modern animals. From thirteen million to two million years ago; there was a growth of mountains; a cooling of the climate; and more and larger mammals.

During this time the global climate became cooler and the number and expanse of grassslands and savannas increased greatly. This change in vegetation was accompanied by an increase in long-legged grazers. In the later part of the epoch, many of the species living in polar regions became extinct.

Coined from Greek pleion, and kainos or cene, "new".