revealed a significant rise in marine oxygenation during the Late Paleozoic era (400 million ... evidence indicating the oxygenation of the ocean at the same time, support the hypothesis that ...

3 min read During the Ordovician period, part of the Paleozoic era ... which was separated from Gondwana by the narrow Iapitus Ocean. Proto-North America straddled the Equator, though to begin ...

The Devonian, part of the Paleozoic era, is otherwise known as the Age of Fishes, as it spawned a remarkable variety of fish. The most formidable of them were the armored placoderms, a group that ...