The Paleozoic era's Silurian period saw animals and plants finally emerge on land. But first there was a period of biological regrouping following the disastrous climax to the Ordovician.

a mere blip in Earth's 4.5-billion-year history. A lot has happened in that time. Earth formed and oxygen levels rose in the foundational years of the Precambrian. The productive Paleozoic era ...

The largest extinction events define a change in era. The end of the Paleozoic and beginning of the Mesozoic 251 million years ago marks the largest mass extinction in the history of the planet, which ...

The ancient fish lived about 305 million years ago during the Late Pennsylvanian period of the Paleozoic Era, the New Mexico ... the New Mexico Museum of Natural History & Science research ...