The Collaborative International Dictionary
Reptilian age
Reptilian \Rep*til"i*an\ (-an), a. Belonging to the reptiles.
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.