Until Now
Biology

Sauropods become the largest land animals ever

A cascade of traits — long neck, small head, bird-like lungs, egg-laying — makes 70-tonne bodies possible.

When
Known to
± 15 million years
Era
Jurassic, Mesozoic

Sauropod gigantism was not one adaptation but a self-reinforcing set. A very long neck reached food nothing else could, and required a small head, which meant no chewing, which meant a huge fermenting gut. Bird-like air sacs lightened the skeleton and cooled the body; laying many small eggs allowed fast population turnover. No land animal since has come close — the largest reached perhaps 70 tonnes.

Just before

Just after