A lot has happened in that time. Earth formed and oxygen levels rose in the foundational years of the Precambrian. The productive Paleozoic era gave rise to hard-shelled organisms, vertebrates ...

Earth has existed for so long (about 4.5 billion ... The Phanerozoic Eon is divided into the three eras. The oldest is the Paleozoic Era, which means ‘ancient life’ and occurred between ...

A recent study shows that marine oxygen levels were crucial to the evolution of early Paleozoic trilobite body size, ...

What did the Late Paleozoic climate and CO₂ look like? Our reconstruction showed that for part of this era the Earth's atmosphere sustained relatively low CO₂ (about 330 parts per million or ...

THE following passage from Suess's “Face of the Earth” might be taken as an appropriate ... The Environment of Vertebrate Life in the Late Paleozoic in North America: A Paleogeographic Study.

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 ...

After Keppie (2000). The Appalachian orogen of North America is divisible with some controversy into five tectonolithologic zones which range in age from Late Precambrian through the Early Paleozoic ...