cenozoic

(also cainozoic, caenozoic) adj. Of the most recent geological era, marked by the evolution and development of mammals etc. n. This era. [greek kainos new, zoion animal]

a. Belonging to the most recent division of geological time, including the tertiary, or Age of mammals, and the Quaternary, or Age of man. [Written also caenozoic, cainozoic, kainozoic.] See Geology.