Researchers can trace prehistoric mammal evolution back another 35 million years.

From herds of feather-covered dinosaurs to dragonflies larger than seagulls, new fossils discovered in China have created new questions about prehistoric feathered beasts.

The insects of today are tiny, and the only giant ones are in nightmares; 320 million years ago, though, dragonflies measuring a meter and centipedes the size of a human thrived on Earth.