Phanerozoic
Concise Oxford English Dictionary © 2008 Oxford University Press:
Phanerozoic /ˌfan(ə)rə(ʊ)ˈzəʊɪk/
▶adjective Geology relating to or denoting the aeon covering the whole of time since the beginning of the Cambrian period about 570 million years ago (comprising the Palaeozoic, Mesozoic, and Cenozoic eras).
'Phanerozoic' also found in these Oxford entries:

