CRETACEOUS

[Cre.ta.ceous] adj [L cretaceus resembling chalk, fr. creta chalk] (1832): of, relating to, or being the last period of the Mesozoic era characterized by continued dominance of reptiles, emergent dominance of angiosperms, diversification of mammals, and the extinction of many types of organisms at the close of the period; also: of, relating to, or being the corresponding system of rocks--see geologic time table -- Cretaceous n