English
wikipedia
Adjective
en-adj
- geology Of a geologic period within the Paleozoic era; comprises lower, middle and upper epochs from about 488 to 443 million years ago.
Proper noun
en-proper noun
- geology The Ordovician period.
See also
Wiktionary appendix:Geologic timescale
fa:Ordovician
zh:Ordovician
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