Reptilian age

(Geol.) that part of geological time comprising the Triassic, Jurassic, and Cretaceous periods, and distinguished as that era in which the class of reptiles attained its highest expansion; - called also the Secondary or Mezozoic age.

See also: Reptilian

Webster's Revised Unabridged Dictionary, published 1913 by G. & C. Merriam Co.