Miocene

[mahy-uh-seen] /ˈmaɪ əˌsin/ Geology

adjective
1.
noting or pertaining to an epoch of the Tertiary Period, occurring from 25 to 10 million years ago, when grazing mammals became widespread.
noun
2.
the Miocene Epoch or Series.
/ˈmaɪəˌsiːn/
adjective
1.
of, denoting, or formed in the fourth epoch of the Tertiary period, between the Oligocene and Pliocene epochs, which lasted for 19 million years
noun
2.
the Miocene, this epoch or rock series
adj.

“pertaining to the geological period between the Oligocene and Pliocene,” 1831, irregular formation from Greek meion “less” + -cene.

A typical example of the monstrosities with which scientific men in want of a label for something, and indifferent to all beyond their own province, defile the language. The elements of the word are Greek, but not the way they are put together, nor the meaning demanded of the compound. [Fowler]

Miocene
(mī’ə-sēn’)
The fourth epoch of the Tertiary Period, from about 24 to 5 million years ago. During this time the climate was warmer than it had been in the Oligocene, and kelp forests and grasslands first developed. With the isolation of Antarctica, a circumpolar ocean current was established in the southern Hemisphere, reducing the amount of mixing of cold polar water and warm equatorial water and causing a buildup of ice sheets in Antarctica. The African-Arabian plate became connected to Asia, closing the seaway which had previously separated Africa from Asia. Mammalian diversity was at its peak. See Chart at geologic time.