ice ages4

Late Permian - cold. Biggest extinction event ever. Lots of ocean circulation. Plants all died.

Triassic, 170 million years ago. Hot. Dinosaurs love it, and are the biggest ever. The pattern is showing that mass extinctions happen when the Earth plunges into cold, and new things happen when the Earth warms up again.

66 million ago, cold. All the dinos die, no need for a meteor impact. Mammals are happy. Going into the modern age - cold.