The growth and lifespan of Parvancorina minchami, small anchor-shaped animals that lived on the seafloor about 550 million ...

revealed a significant rise in marine oxygenation during the Late Paleozoic era ... the oxygenation of the ocean at the same time, support the hypothesis that animals have evolved in oceans ...

3 min read During the Ordovician period, part of the Paleozoic ... group-living animals that built coral-like structures. Ordovician reefs were also home to large sea lilies, relatives of sea ...

The Paleozoic era's Silurian period saw animals and plants finally emerge on ... way in the oceans as climbing temperatures and rising sea levels reproduced the shallow, marine environments ...