[sometimeso-] designating or of the second geologic period of the Paleozoic Era, characterized by the development of abundant marine invertebrates and the first vertebrates
Origin of Ordovicianfrom Classical Latin Ordovices, ancient Celtic tribe in Wales
the Ordovician Period or its rocks
Of, relating to, or being the period of geologic time from about 488 to 444 million years ago, the second period of the Paleozoic Era. It is characterized by a major increase in marine biodiversity and the appearance of the supercontinent Gondwana. Some evidence suggests that the first land plants appeared at this time. geologic time
The Ordovician Period.
Origin of OrdovicianFrom Latin Ordovicēs an ancient Celtic tribe of Wales from Celtic Ordovices ; see weik-3 in Indo-European roots.