Direct chemical evidence has shown that T. rex maintained a body temperature of around 36°C. This helps explain how the huge predator could be so large and active.
Researchers at the University of California, Los Angeles determined the figure from chemical traces in tooth enamel. Dinosaurs were once often portrayed as giant lizards whose activity depended on the environment. It is now clear that T. rex could maintain a constant high body temperature, and therefore may have had a fast metabolism and remained active in a range of climates.
Warm-bloodedness also helps explain how T. rex could live in cold regions: its remains have been found even in what is now Alaska.
