Paleozoic Era Fossils
The Paleozoic was a time much different than today. The animals that lived on Earth were mainly invertebrate animals meaning they didn’t have a backbone. Many descendents of those animals live on our planet today but there is also an abundance of vertebrate animals, those with backbones. Animals in the early Paleozoic lived almost exclusively in marine habitats. By the end of the Devonian, however, vertebrate animals had begun to migrate onto land through new evolutionary traits. The Late Paleozoic contained a boom in global land plants, forming much of the coal mined on the planet today.