Ordovician Hear it!

Ordovician Definition

Or·do·vi·cian (ôr′də vis̸h′ən)

adjective

designating or of the second geologic period of the Paleozoic Era, characterized by the development of abundant marine invertebrates and the first vertebrates

Etymology: < L Ordovices, ancient Celtic tribe in Wales

Ordovician Idioms

the Ordovician

the Ordovician Period or its rocks