Definition of cretaceous period in English English dictionary
Interval of geologic time from 144 to 65 million years ago. During the Cretaceous the climate was warmer than today. In the seas, marine invertebrates flourished, and bony fishes evolved. On land, flowering plants arose, and insects, bees in particular, began their thriving partnership with them. Mammals and birds remained inconspicuous throughout the Cretaceous, while the reptiles continued their dominance. The dinosaurs reached the peak of their evolution during this period but rather suddenly became extinct at its end
{i} geologic timescale from 135 million to 63 million years ago; end of the age of reptiles; appearance of modern insects and flowering plants