Ne·o·prot·er·o·zo·ic 
(nē′ō-prŏt′ər-ə-zōĭk, -prō′tər-)
(nē′ō-prŏt′ər-ə-zōĭk, -prō′tər-)adj.
Of, relating to, or being the most recent of the three eras of the Proterozoic Eon, from approximately 1.0 billion to 542 million years ago, marked by the formation of extensive glaciers reaching as far south as the equator and the first appearance of multicellular life. See Table at geologic time.
n.
The Neoproterozoic Era.