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. See Table at geologic time.
The Ordovician Period.
[From Latin Ordovicēs, an ancient Celtic tribe of Wales, from Celtic Ordovices; see weik-3 in the Appendix of Indo-European roots.]
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