Relating to the earliest epoch of the Tertiary or the corresponding system of rocks; period of great development of primitive mammals.
She's as real as"-he looked around; he picked up the tiny, wedgelike skull of Barney, a 60-million-year-old Paleocene rodent, and held it up-"as real as Barney."
She had shinnied up the goalpost, tightrope-walked out to the middle of the crossbar and was now standing there with her arms raisied in a touchdown sign.