Why did This Dinosaur Have a 'Crazy Straw' Inside its Head?

Ankylosaurs thick full-body armor protected them from predators, but it did not allow much heat to escape from their huge body. Paleontologists were puzzled at how these animals were able to regulate their temperature and survive under the blazing Cretaceous-period sun. That is, they were puzzled until they scanned its huge, bony skull.