Hotter Than a Sleepy Crocodile, Cooler than a Soaring Eagle!

Hot-blooded? Check it and see. (Courtesy Paramount Pictures)

Hot-blooded? Check it and see.
(Courtesy Paramount Pictures)

Whether dinosaurs were warm- or cold-blooded has been debated since the first bones were found in the 19th Century, but a new test performed on fossilized titanosaur sauropod and oviraptorid theropod eggs provides new evidence that…

Well, it’s complicated:

“The temperatures we measured suggest that at least some dinosaurs were not fully endotherms like modern birds,” Eagle said. “They may have been intermediate—somewhere between modern alligators and crocodiles and modern birds; certainly that’s the implication for the oviraptorid theropods.”

“This could mean that they produced some heat internally and elevated their body temperatures above that of the environment but didn’t maintain as high temperatures or as controlled temperatures as modern birds,” he added. “If dinosaurs were at least endothermic to a degree, they had more capacity to run around searching for food than an alligator would.”

The study was the first direct measurement of body temperatures in two types of dinosaurs. Tripati said it shows clearly that they are different from each other.

The researchers also analyzed fossil soils, including minerals that formed in the upper layer of the soil on which the oviraptorid theropods’ nests were built. This enabled them to estimate that the environmental temperature in Mongolia shortly before the dinosaurs went extinct was approximately 79 degrees Fahrenheit.

“The oviraptorid dinosaur body temperatures were higher than the environmental temperatures—suggesting they were not truly cold-blooded, but intermediate,” Tripati said.

We may never know until we build a theme park for them.