The Ordovician period
486.85 to 443.1 million years ago · Paleozoic era. Ages from the ICS International Chronostratigraphic Chart.
The Earth about 470 million years ago (Merdith et al. 2021 plate model). Explore this period on the timeline: 445 Ma · 470 Ma
| Began | 486.85 million years ago |
|---|---|
| Ended | 443.1 million years ago |
| Era | Paleozoic |
| Epochs | Early Ordovician (486.85–471.3 Ma), Middle Ordovician (471.3–458.2 Ma), Late Ordovician (458.2–443.1 Ma) |
| Duration | 43.8 million years |
About the Ordovician
The Ordovician ( or-də-VISH-ee-ən, -doh-, -VISH-ən) 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 486.85 Ma (million years ago) to the start of the Silurian Period 443.1 Ma.
The Ordovician, named after the Welsh tribe of the Ordovices, was defined by Charles Lapworth in 1879 to resolve a dispute between followers of Adam Sedgwick and Roderick Murchison, who were placing the same rock beds in North Wales in the Cambrian and Silurian systems, respectively. Lapworth recognized that the fossil fauna in the disputed strata were different from those of either the Cambrian or the Silurian systems, and placed them in a system of their own. The Ordovician received international approval in 1960 (forty years after Lapworth's death), when it was adopted as an official period of the Paleozoic Era by the International Geological Congress.
Featured animals of the Ordovician (3)
Text in “About” is quoted from the Wikipedia article Ordovician (revision 1381342902), licensed under CC BY-SA 4.0; introduction excerpted verbatim. Ages and colours: ICS chart (v2024/12) via the Paleobiology Database.