Surprisingly, Earth’s creatures were highly diverse during the Carboniferous and Permian Eras (the time before dinosaurs) and also enormous. Unearth the nine massive prehistoric animals that ...

Less than 5 percent of the animal species in the seas survived ... For years scientists have known that the deep ocean lacked oxygen in the late Permian. But most life is concentrated in shallow ...

Crinoids are a group of eerie, perfectly symmetrical creatures that include sea lilies and sea feathers ... with 95% of life on Earth — during the Permian mass extinction roughly 251 million ...