- noting or pertaining to the present era, beginning 65 million years ago and characterized by the ascendancy of mammals.
- the Cenozoic Era or group of systems.
- of, denoting, or relating to the most recent geological era, which began 65 000 000 years ago: characterized by the development and increase of the mammals
- the Cenozoic the Cenozoic era
1841, Cainozoic, from Latinized form of Greek kainos “new, fresh, recent, novel” (see recent) + zoon “animal” (see zoo). The era that began with the demise of the dinosaurs and the rise of “recent” species.
- The most recent era of geologic time, from about 65 million years ago to the present. The Cenozoic Era is characterized by the formation of modern continents and the diversification of mammals and plants. Grasses also evolved during the Cenozoic. The climate was warm and tropical toward the beginning of the era and cooled significantly in the second half, leading to several ice ages. Humans first appeared near the end of this era. See Chart at geologic time.