Because of the size of the specimens, the bones were originally categorized by the New Mexico Museum of Natural History & Science as T. rex, which grew up to 39 feet (12 meters) long and 10 tons ...

A more slender jaw, even with the big teeth, means that it would have less bite force.” The other big difference was that, unlike T. rex, T. mcraeensis didn’t have a prominent ridge over its eyes.