cretaceous period

from WordNet (r) 3.0 (2006)

Cretaceous period
    n 1: from 135 million to 63 million years ago; end of the age of
         reptiles; appearance of modern insects and flowering plants
         [syn: {Cretaceous}, {Cretaceous period}]

from The Collaborative International Dictionary of English v.0.48

Cretacic \Cre*tac"ic\
   [Webster 1913 Suppl. +PJC]

   {Cretaceous acid},
   an old name for carbonic acid.

   {Cretaceous formation} (Geol.), the series of strata of
      various kinds, including beds of chalk, green sand, etc.,
      formed in the Cretaceous period; -- called also the {chalk
      formation}. See the Diagram under {Geology}.

   {Cretaceous period} (Geol.), the time in the latter part of
      the Mesozoic age during which the Cretaceous formation was
      deposited, and at the end of which the dinosaurs died out.
      See {Cretaceous}.
      [1913 Webster +PJC]