Definition of Cretaceous adjective from the Oxford Advanced American Dictionary

 

Cretaceous

 adjective
adjective
NAmE//krɪˈteɪʃəs//
 
(geology)
 
jump to other results
of the period between around 146 to 65 million years ago, when dinosaurs lived (until they died out); of the rocks formed during this time
the Cretaceous
 
jump to other results
 
noun [singular]
See the Oxford Advanced Learner's Dictionary entry: Cretaceous