Armored Dinosaurs Had Built-In Air Conditioning
Sweating, panting, sitting in the shade or taking a nice cold dip are all ways animals try to cool down in the sweltering heat. It's too bad they can't just enjoy a little air conditioning. Well, new research shows that at least for armored dinosaurs, they did, by using their long, winding nasal passages to change the temperature of the air they breathed.
Armor-plated dinosaurs, or ankylosaurs, sported protective plates that covered their head and shoulders, and even in some cases their eyelids, according to BBC Nature. Resembling something of a reptilian armadillo, these ferocious spiked herbivores also wielded a large, heavy club at the end of their tail to be used as a weapon, and as a tool for mate selection, as some scientists suggest.
With all this heavy armor on, these plant-eaters were bound to sweat in the scorching heat, so it's no wonder they had to find a better way to cool down.
A team of scientists at Ohio University used CT scans to document the anatomy of nasal passages in two different ankylosaur species. Following 3D reconstruction of these passages, the researchers discovered that as these dinosaurs inhaled, air was given more time and more surface area to warm up to body temperature. By drawing heat away from nearby blood vessels, the blood would be cooled and travel to the brain to keep its temperature stable, acting as sort of a built-in air conditioner for these prehistoric tanks.
This is an entirely different cooling mechanism compared to modern mammals and birds which use scroll-shaped bones called conchae or turbinates to warm inhaled air.
"There are two ways that animal noses transfer heat while breathing," lead paleontologist Jason Bourke said in a press release. "One is to pack a bunch of conchae into the air field, like most mammals and birds do - it's spatially efficient. The other option is to do what lizards and crocodiles do and simply make the nasal airway much longer. Ankylosaurs took the second approach to the extreme."
If it weren't for these long nasal passages, or "crazy straw" airways as scientists call them, these multi-ton ankylosaurs were bound to overheat.
The findings were presented last week at the 2014 annual meeting of the Society of Vertebrate Paleontology in Berlin.