Something dramatic happened about 500 million years ago called the Cambrian "explosion," during which an incredible diversity ...
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 ...
Then, about 540 million years ago, something else changed ... dramatically. It was the time of the Cambrian Explosion, an eruption of life when Earth’s very first animals began appearing in the ...