オルドビス紀
Also known as Ordovician Period, Ordovician System
The Ordovician ( ) is a geologic period and system, the second of six periods of the Paleozoic Era, and the second of twelve periods of the Phanerozoic Eon. The Ordovician spans 43.75 million years from the end of the Cambrian Period Ma (million years ago) to the start of the Silurian Period Ma.
AI overview
The Ordovician is a geologic period that occurred roughly 485 to 444 million years ago, making it the second major division of the Paleozoic Era. It matters because it represents a significant chapter in Earth's history when the planet's geology and life forms were evolving in important ways between the Cambrian and Silurian periods.
AI-generated from the Wikipedia summary — may contain errors.
Key facts
- Geologic timespan.name
- Ordovician
- Geologic timespan.color
- Ordovician
- Geologic timespan.image_map
- Mollweide Paleographic Map of Earth, 465 Ma (Darriwilian Age).png
- Geologic timespan.caption_map
- A map of Earth as it appeared 465 million years ago during the Middle Ordovician Epoch
- Geologic timespan.timeline
- Ordovician
- Geologic timespan.name_formality
- Formal
- Geologic timespan.name_accept_date
- 1960
- Geologic timespan.celestial_body
- earth
- Geologic timespan.usage
- Global (ICS)
- Geologic timespan.timescales_used
- ICS Time Scale
- Geologic timespan.chrono_unit
- Period
- Geologic timespan.strat_unit
Article · 日本語
オルドビス紀（オルドビスき、Ordovician period）とは、地質時代、古生代前期における区分で、約4億8830万年前から約4億4370万年前までを指す。オルドビスの名前は、模式地であるウェールズ地方に住んでいた古代ケルト系部族「」(Ordovices) からついた。奥陶紀（おうとうき）ともいう。 オルドビス紀は、生物の多様化がカンブリア紀並に進んだ時代である。オウムガイに代表される軟体動物や三葉虫のような節足動物、筆石のような半索動物が栄えた。また、オルドビス紀後期には顎を持つ魚類が登場した。 オルドビス紀末には大量絶滅が起こった。
Abstract from DBpedia / Wikipedia · CC BY-SA
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