designating or of the first geologic epoch of the Paleogene, characterized by lower sea levels, the development of modern mountain ranges, and the development of flowering plants, birds, and mammals
Origin of Paleocenepaleo- + -cene
the Paleocene Epoch or its rocks
Of, relating to, or being the epoch of geologic time from 65 to 55 million years ago, the oldest epoch of the Tertiary Period. It is characterized by the formation of the Rocky Mountains and by the appearance of placental mammals. See Table at geologic time.
The Paleocene Epoch.