Crossword clue: of or relating to or denoting the third period of the mesozoic era
1 answer found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).
Possible answers
cretaceous
10 letters
wn-def
from 135 million to 63 million years ago; end of the age of reptiles; appearance of modern insects and flowering plants