Book 32, Question 113
Why does a frilled lizard open a giant frill?
When an Australian frilled lizard is startled, it opens its mouth wide and flares a big collar of skin around its neck.
The frill is held out by thin rods of cartilage, and it makes the lizard look much bigger. Then it may hiss and race away on two legs. The frill may also help the lizard warm up by catching sunlight.