Early in the Cretaceous, hordes of parrot dinosaurs – the psittacosaurs – lived in China and Mongolia. Not much heavier than a big turkey, psittacosaurs used their long, strong hind claws to dig burrows where they curled up to escape unpleasant weather. Some psittacosaurs fossilized as entire crèches – groups of youngsters who had hatched together, huddled side by side. Sudden floods buried the babies in a thick blanket of mud. Parrot dinosaurs had, for their size, the strongest bite force of any dinosaur herbivore. Tall, strong beaks and enlarged jaw muscles let the psittacosaurs cut through hard-shelled fruit and tough leaves. At first sight, psittacosaurs, with their long hind limbs and short front legs, seem quite different from gigantic quadrupedal dinosaurs like Triceraptops. But if you look closely at the psittacosaurs beak, you’ll see a clue to its close relationship.