The earliest amniotes were reptiles, and are thought to have emerged from prehistoric amphibians in the late Carboniferous period roughly 318 million years ago. These early amniotes saw many ...

Amniotes began to radiate in the Carboniferous into many niches previously held by amphibians, plus new niches. The initial split was into synapsids (mammals and their relatives) and sauropsids ...

This time period took place 359 to 299 million years ago. 3 min read The Carboniferous period, part of the late Paleozoic era, takes its name from large underground coal deposits that date to it.