Mesozoic

 
Pronunciation: /ˌmɛsə(ʊ)ˈzəʊɪk, ˌmɛz-, ˌmiːs-, ˌmiːz-/

adjective

Geology
  • relating to or denoting the era between the Palaeozoic and Cenozoic eras, comprising the Triassic, Jurassic, and Cretaceous periods.
  • (as noun the Mesozoic) the Mesozoic era or the system of rocks deposited during it.
  • The Mesozoic lasted from about 245 to 65 million years ago. Large reptiles were dominant on land and sea and the first mammals, birds, and flowering plants appeared

Origin:

mid 19th century: from meso- 'intermediate' + Greek zōion 'animal' (referring to the appearance of the first mammals) + -ic