Paleozoic Era · Ordovician Period
Earth 450 Million Years Ago: The Ordovician
Earth 450 million years ago in the Ordovician: rich seas, the first plants on land, and Gondwana drifting over the South Pole towards an ice age.
Spin it in 3D and move through timeMap: Ancient maps: PALEOMAP PaleoDEMs (Scotese & Wright 2018), CC BY 4.0 · Natural Earth.
In the Ordovician, life in the sea diversified enormously, in what is called the Great Ordovician Biodiversification Event: reefs, nautiloids, sea lilies and the first jawless fish. The first land plants, small and moss-like, had appeared by about 470 million years ago.
Gondwana was drifting over the South Pole. Around 445 million years ago an ice sheet spread across what is now the Sahara, sea levels dropped and the seas cooled, causing the end-Ordovician mass extinction, which killed around 85% of marine species.
The Iapetus Ocean was closing as Baltica and Avalonia approached Laurentia, raising the first stages of the Appalachian and Caledonian mountains.
Events of the time
Ice sheet over the Sahara
445 million years ago · North Africa
Scratched rock and glacial deposits in the Sahara show that ice covered North Africa when it lay over the South Pole. The cold and falling seas killed about 85% of marine species.
Part of the Paleozoic Era & The Cambrian Explosion.