, ( PAL-ee-ə-seen, -ee-oh-, PAY-lee-, -lee-oh-
) or Palaeocene
, is a geological epoch
that lasted from about 66 to 56 million years ago
(mya). It is the first epoch of the Paleogene Period
in the modern Cenozoic Era
. The name is a combination of the Ancient Greek παλαιός palaiós
meaning "old" and the Eocene
Epoch (which succeeds the Paleocene), translating to "the old part of the Eocene".
The epoch is bracketed by two major events in Earth's history. The K–Pg extinction event
, brought on by an asteroid impact
and possibly volcanism, marked the beginning of the Paleocene and killed off 75% of living species, most famously the non-avian dinosaurs. The end of the epoch was marked by the Paleocene–Eocene Thermal Maximum
(PETM), which was a major climatic event wherein about 2,500–4,500 gigatons of carbon were released into the atmosphere and ocean systems, causing a spike in global temperatures and ocean acidification
. (Full article...