Plio-Pleistocene

The term Plio-Pleistocene refers to an informally described geological pseudo-period, which begins about 5 million years ago (mya) and, drawing forward, combines the time ranges of the formally defined Pliocene and Pleistocene epochs—marking from about 5 mya to about 12 kya. Nominally, the Holocene epoch—the last 12 thousand years—would be excluded, but most Earth scientists would probably treat the current times as incorporated into the term "Plio-Pleistocene" ;see below.

In the contexts of archaeology, paleontology, and paleoanthropology, the Plio-Pleistocene is a very useful period to which scientists may assign the long and continuous run in East Africa of datable sedimentary layers and their contents; (for one example, see the Bouri Formation). These contents collectively present a focused view of the continuous evolution of the region's large vertebrates, especially the evolution of some African apes (hominids) to the earliest hominins; and then the development of the early humans and their toolmaking cultures. This shorter pseudo-period—from after 5 mya to about 1.5 mya—straddles the boundary between the Pliocene and the Pleistocene. Thereafter the Plio-Pleistocene formations in East Africa contain, and disclose, the genus Homo developing into archaic Homo sapiens, then to anatomically modern humans.