Paleozoic Era · Devonian Period
Earth 400 Million Years Ago: The Age of Fishes
What Earth looked like 400 million years ago in the Devonian: the Age of Fishes, the first insects, and plants spreading over the land.
Spin it in 3D and move through timeMap: Ancient maps: PALEOMAP PaleoDEMs (Scotese & Wright 2018), CC BY 4.0 · Natural Earth.
The Devonian is called the Age of Fishes: armoured placoderms, sharks and lobe-finned fish filled the seas and rivers. Some lobe-finned fish were the ancestors of the first four-legged animals, which appeared by about 375 million years ago.
On land, plants with veins to carry water were spreading inland. The Rhynie chert of Scotland, about 407 million years old, preserves one of these early ecosystems in detail, with plants, fungi and some of the first insects and spiders.
North America and northern Europe had joined into Laurussia, the “Old Red Sandstone continent”, along the Caledonian mountains. Gondwana still lay to the south across the narrowing Rheic Ocean.
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.
Gilboa fossil forest
385 million years ago · New York, USA
Stumps of some of the earliest known trees, about 8 m tall, which had fronds instead of leaves.
Part of the Paleozoic Era & The Cambrian Explosion.