Not the Biggest Meat-Eating Dinosaur
Most people assume that the North American Tyrannosaurus rex was the biggest carnivorous dinosaur that ever lived. However, T. rex was equaled or outclassed by not one but two dinosaurs: the South American Giganotosaurus, and the northern African Spinosaurus.
Arms Not as Tiny as Once Thought
One feature of Tyrannosaurus rex that everyone makes fun of is its arms, which seem disproportionately tiny compared to the rest of its massive body. T. rex's arms were over three feet long, however, and may have been capable of bench pressing 400 pounds each.
Very Bad Breath
What is known about the four-foot jaws and mouth of Tyrannosaurus rex is it contained about 60 serrated teeth (some 12 inches long) ready for tearing meat and its breath was most likely horrendous.
Females Bigger Than Males
There's a good reason to believe, based on fossils and the shapes of the hips, that the female T. rex outweighed the male by a few thousand pounds.