BP

Before Present, used in historical terms to describe a date which was previous to today's.

Vito: hey did you know the Elasmotherium was alive at 26,000 BP? They were certified by the Rhino mafia to be the most badass Rhino to ever Rhino the Earth.

Paulie: no i did not know this amazing fact. Man I wish I knew more about the Elasmotherium.