Phanerozoic

[ fan-er-uh-zoh-ik ]

noun

1. the eon comprising the Paleozoic, Mesozoic, and Cenozoic eras.

adjective

1. of or relating to this eon.

Phanerozoic

/ ˌfænərəˈzəʊɪk /

adjective

1. of or relating to that part of geological time represented by rocks in which the evidence of life is abundant, comprising the Palaeozoic, Mesozoic, and Cenozoic eras

noun

1. the Phanerozoic
   the Phanerozoic era

Phanerozoic

/ făn′ər-ə-zō′ĭk /

1. The period of geologic time from about 540 million years ago to the present, including the Paleozoic, Mesozoic, and Cenozoic Eras. When this period of time was first defined, it was thought to coincide with the first appearance of life in the fossil record. It is now known that bacterial and other forms of life were present in the Precambrian Eon, and the Phanerozoic is understood to coincide with the appearance of life forms that evolved external skeletons.
2. See Chart at geologic time

Word History and Origins

Origin of Phanerozoic¹

1925–30; < Greek phaneró ( s ) manifest, visible + zo- + -ic