Crinoids are often referred to as “sea lilies” even though they’re technically animals, not plants. They have been around since the late Cambrian, some 500 million years ago — 250 million ...

Learn more about a time period marked by an intense burst of evolution. 3 min read The Cambrian period, part of the Paleozoic era, produced the most intense burst of evolution ever known.

All animal evolution for the last half billion years has come from tinkering with these Cambrian body plans. Then, between about 570 and 530 million years ago, another burst of diversification ...