age of mammals

from WordNet (r) 3.0 (2006)

Age of Mammals
    n 1: approximately the last 63 million years [syn: {Cenozoic},
         {Cenozoic era}, {Age of Mammals}]

from The Collaborative International Dictionary of English v.0.48

Mammal \Mam"mal\, n.; pl. {Mammals}. [L. mammalis belonging to
   the breast, fr. mamma the breast or pap: cf. F. mammal.]
   (Zool.)
   One of the Mammalia.
   [1913 Webster]

   {Age of mammals}. See under {Age}, n., 8.
      [1913 Webster]