Earth formed and oxygen levels rose in the foundational years of the Precambrian. The productive Paleozoic era gave rise to hard-shelled organisms, vertebrates, amphibians, and reptiles.

Many different representations of the timeline have been created, and many approaches developed by informed ... The largest extinction events define a change in era. The end of the Paleozoic and ...

This type of CO₂ reconstruction from Earth's deep geologic past is entirely novel. Crucially, the reconstruction has a ...

3 min read During the Ordovician period, part of the Paleozoic era, a rich variety of marine life flourished in the vast seas and the first primitive plants began to appear on land—before the ...