Marine animals evolve toward larger bodies over time: Study

The average size of marine animals has increased by a factor of 150 since the Cambrian Period began about 542 million years ago, a US study has said.

Some dinosaurs followed Cope’s Rule and became larger over time

In the evolutionary long run, small critters tend to evolve into bigger beasts—at least according to the idea attributed to paleontologist Edward Cope, now known as Cope’s Rule.