Ordovician period
Rare geological term; the standard modern term is オルドビス紀. This kanji form is seldom used outside older or specialized texts.
See also: オルドビス紀
The Ordovician period is a division of the Paleozoic era, also called オルドビス紀.
Borrowed from Chinese 奥陶紀, the Chinese name for the Ordovician period; 奥陶 represents the beginning of the transliterated name 奥陶維斯.