Tyrannosaurus rex had a built-in air conditioner: study

PanARMENIAN.Net - One of the largest predators to ever walk the Earth needed to cool off every now and then, CNN reports.

Researchers believe they have now unlocked the secret to how Tyrannosaurus rex maintained a cool head. The carnivorous dinosaur had something akin to an air conditioner in its skull, according to a new study published Wednesday in the The Anatomical Record.

Previously discovered skulls belonging to T. rex included two large holes at the top. These were referred to a dorsotemporal fenestra. In the past, scientists believed this part at the roof of the skull was equipped with muscles that aided in T. rex's powerful jaw movements.

The researchers involved in the new study, including University of Missouri-Columbia professor of anatomy Casey Holliday, had a more difficult time making that connection.

"It's really weird for a muscle to come up from the jaw, make a 90-degree turn, and go along the roof of the skull," said Holliday, lead resaercher. "Yet, we now have a lot of compelling evidence for blood vessels in this area, based on our work with alligators and other reptiles."

To understand what might have been going on in T. rex's head, the researchers applied thermal imaging to modern reptiles.

Thermal imaging allows heat to be translated into visible light. The researchers used this technique on alligators at the St. Augustine Alligator Farm Zoological Park in Florida.

"An alligator's body heat depends on its environment," said Kent Vliet, study author and coordinator of laboratories at the University of Florida's Department of Biology. "Therefore, we noticed when it was cooler and the alligators are trying to warm up, our thermal imaging showed big hot spots in these holes in the roof of their skull, indicating a rise in temperature. Yet, later in the day when it's warmer, the holes appear dark, like they were turned off to keep cool."

This matches up with previous research on alligators and their cross-current circulatory system, "or an internal thermostat, so to speak,' Vliet said.