The curious minds at What If transport us to the Paleozoic Era and envision what life would be like in this ancient period.

This may have been what life looked like in an oxygen-rich environment during a period of the early Paleozoic Era (541 million years ago to 252 million years ago), showcasing the largest creepy ...

“The Permian was the last period of the Paleozoic Era. “Dinosaurs lived during the Mesozoic Era from around 251 to 66 million years ago.” Shepperd said the distinction between the Paleozoic ...

The animal in question is Pleurocystites, a genus of marine invertebrate that lived about 450 million years ago during the Paleozoic era and is thought to be one of the first groups of echinoderms ...

“The Richards Spur locality in Oklahoma preserves the richest, most diverse assemblage of exclusively terrestrial vertebrates for the Paleozoic Era,” according to the study. The piece of ...

The ancient fish lived about 305 million years ago during the Late Pennsylvanian period of the Paleozoic Era, the New Mexico Department of Cultural Affairs said in a Jan. 10 news release.

Horseshoe crabs first developed 540 million years ago in the Paleozoic era, more closely related to arachnids than crabs. The amazing arthropods lived through the age and extinction of dinosaurs and ...

By Rebecca Dzombak Most modern scorpions would fit in the palm of your hand. But in the oceans of the Paleozoic era more than 400 million years ago, animals known popularly as sea scorpions were ...