A major division of geological time; an era is usually divided into two or more periods(noun)
WordNet. Princeton University. 2010.
Use "geological era" in a sentence
"As implied by the word petrefaction, most palæontological remains have been transformed into stone, but leaves and bones completely incrusted in limestone, and therefore petrified, have been found which belong to the present geological era and are, therefore, not considered fossils, whereas the skeletons of the mammoth and rhinoceros frozen in the ice of Siberia, or the insects preserved in amber are."
"Devonians’ takes us back 360 million years, to the geological era when the first forests began to appear."