Armored Dinosaurs Came with Built-In Air Conditioning

Some animals sweat and some pant, while others hide in the shade or, if they're lucky, some body of water. The alternative is, well, death: hyperthermia, heat stroke.

Dinosaurs would've had it rough, what with those shells and all. Sweating won't do much good under there, and can you even imagine some 65 ton dreadnoughtus panting like a dog? According research presented yesterday at the 74th Annual Meeting of The Society of Vertebrate Paleontology, armored dinosaurs came customized with a clever system of air cooling: giant, convoluted nasal passageways.

The fundamental principle isn't unusual in the animal kingdom. Birds and many mammals come equipped with seashell-like bone structures, concha, within their nasal passageways that act to regulate the flow of air across the nose's various climate-controlling tissue. It's not a straight shot from nostril to lung—air is purified, humidified, and warmed first.

Dinosaurs had something a bit different. Using 3D reconstructions of the nasal corridors of two species of ankylosaur (armored dinosaur), the paleontologists found that the additional twists and turns built into dino-noses functioned to regulate the temperature of incoming air. This process allowed heat to be drawn away from blood vessels by the air as it warms to the dinosaur's body temperature, cooling the blood itself. This lower-temperature blood then goes on to cool dino-brains.

"These airflow patterns resulted in increased air transit times that enhanced airway-nasal-wall interactions," the presentation's abstract explains.

"Assuming extensive blood flow to the nasal airway, such airway-nasal-wall interactions indicate that both ankylosaurs had the potential to extensively modify the heat content of respired air, affecting its moisture-holding capacity and reducing respiratory evaporative water loss," the summary continues. "This potential to warm inspired air would, in turn, provide a reservoir of cooled blood that could be shunted to the brain, maintaining stable cerebral temperatures during times of heat stress."

"Our team discovered these 'crazy-straw' airways several years ago," explained Lawrence Witmer, a member of the nose-modeling research team, in a statement. "But only recently have we been able to scientifically test hypotheses on how they functioned. By simulating airflow through these noses, we found that these stretched airways were effective heat exchangers. They would have allowed these multi-tonne beasts to keep their multi-ounce brains from overheating."