The Phanerozoic Eon is the current geologic eon in the geologic time scale, and the one during which abundant animal and plant life has existed. It covers 541 million years to the present, and it began with the Cambrian Period when animals first developed hard shells preserved in the fossil record.

What does the name Phanerozoic mean?

Its name derives from the Ancient Greek words φανερός (phanerós), meaning visible, and ζωή (zōḗ), meaning life; since it was once believed that life began in the Cambrian, the first period of this eon. The term "Phanerozoic" was coined in 1930 by the American geologist George Halcott Chadwick (1876–1953).

What is Phanerozoic in earth science?

Phanerozoic The period of geological time that comprises the Palaeozoic, Mesozoic, and Cenozoic Eras. It began 542 Ma ago at the end of the Precambrian and is marked by the accumulation of sediments containing the remains of animals with mineralized skeletons. The name means the period of 'visible' or 'obvious life'.