the same reason as the other dinosaurs
a t rex was extinct in 5,333
They're not. They're extinct.
The large, extinct, carnivorous dinosaur was named Tyrannosaurus (Latin "tyrant lizard"), or Tyrannosaurus Rex. It could be referred to as either a "tyrannosaurus" or simply "tyrannosaur".
Stegosaurus,Tyrannosaurus and Brontosaurus
approx. 300000 B.C., but they lived in the jurrasic period
Never. Velociraptor went extinct before tyrannosaurus evolved and even then they were far too small to be a threat to something as large as T. rex.
Pterodactyl, Tyrannosaurus Rex, brontosaurus.
Koalas are not extinct.
Tyrannosaurus rex is an acient extinct dinosaur. It was one of the top predetors of it's time.
The Tyrannosaurus Rex died out at the end of the Cretaceous period, 65 million years ago.
With the fishes, so to speak; in other words, they're extinct. If your question is actually "Did tyrannosaurus sleep?", then the answer, though conjecture, would still have to be an emphatic yes. The dinosaurs' closest living relatives are birds, and birds sleep.
Hmm, strongest extinct animal... think giant shark with teeth the size of bananas! That's the Megalodon, and it could chomp through whales like cheese crackers!