Dinosaur skulls have something in common with Swiss cheese—they’re both full of holes. From Tyrannosaurus to Triceratops, the skulls of the terrible lizards have the same eye and nasal passages common in many vertebrates, as well as additional pockets unique to reptiles. For example, a hole at the top and rear of the skull anchored jaw muscles for chomping through the Mesozoic world—and a new study suggests there was more to this peculiar anatomical window than just biting. The prehistoric skulls of dinos may have held special blood vessels that allowed the animals to keep their brains at just the right temperature.
Digging in further, the research team compared the past to the present. In addition to detailed examinations of fossil dinosaur skulls, the paleontologists also looked to some of dinosaurs’ closest living relatives—American alligators and wild turkeys—to see if there might be unidentified soft tissues in this skeletal divot. Their results were published today in The Anatomical Record.
The blood vessel networks may have had another advantage as well. Dinosaurs like the triple-horned carnivore Ceratosaurus and many tyrannosaurs had skull ornaments, or lavish head displays, in the vicinity of these blood vessels. The bone would have been covered in keratin in life, nourished by the same cardiovascular system that controls temperature. The blood vessels that helped dino brains warm or cool could have also allowed these animals to develop extravagant headgear, co-opting a temperature function into something flashy, such as the tube-like crest of Parasaurolophus or the long brow horns of Pentaceratops.
https://www.smithsonianmag.com/science-nature/special-skull-windows-helped-dinosaurs-keep-their-brains-keep-cool-180973036/