See the skeleton Tyrannosaurus rex Kingdom Animalia (animals) Phylum Chordata (animals with spinal nerve cords) Subphylum Vertebrata (chordates with backbones) Class Archosauria ("ruling reptiles") Subclass Dinosauria (extinct reptiles, "terrible lizards") Order Saurischia (lizard-hipped) Suborder Theropoda (beast-footed) Family Tyrannosauridae Carnosauria (tyrant meat-eating lizard) Genus Tyrannosaurus (tyrant) Species rex (king)

Meet Stan the T. rex

Stan is a Tyrannosaurus rex (T. rex) which means "tyrant lizard king."

Stan lived in the Late Cretaceous Period, around 65 million years ago. Tyrannosaurs like Stan could be found in parts of western North America.

Unlike Bucky the Teenage T. rex, Stan is an adult T. rex.

T. rex was a carnivore, which means it ate meat instead of plants. Its teeth and strength came in handy when it ate. It had more than 50 teeth, the largest of which were up to 7 inches long and sharp like saw-edged steak knives. Its upper teeth were curved and very sharp like butcher's knives. T. rex didn't eat tiny, polite bites. Its teeth and strong jaw muscles enabled it to tear off and eat large chunks of meat from its prey.

From studying the way T. rex teeth were worn down, scientists believe that it likely ate tough, fresh meat instead of rotting meat from animals already dead. This means that T. rex was a predator rather than a scavenger.

As a tyrannosaur's teeth got old, the long roots of the teeth dissolved so they could fall out and be replaced by new teeth.

Interesting Things About Stan

Stan has probably the best preserved and most complete dinosaur skull ever discovered. Nearly every fossilized bone of Stan's skull was discovered during excavation.

The fossilized bones in Stan's skull were found separated from each other. This is important because it allowed the bones to be preserved for millions of years in excellent condition with little distortion or crushing. It also gave scientists the opportunity to study each fossilized bone and determine how the bones connected and moved in relation to each other.

Forty-seven separate fossilized bones and 35 loose fossilized teeth were assembled in the reconstruction of Stan's skull. The only missing bones were two small skull pieces from Stan's lower jaw.

The study of Stan's skull led scientists to believe T. rex had the largest brain, the best eyesight, the best sense of smell, the strongest teeth and the most powerful jaw of all the dinosaurs in the Late Cretaceous Period at the end of the Age of Dinosaurs.

Stan had several broken and healed ribs, a broken neck and a hole in the back of its skull.

Stan's Discovery

In 1987, amateur paleontologist Stan Sacrison was exploring in the Hell Creek Formation near the town of Buffalo, South Dakota, when he discovered a large fossilized bone sticking out of a sandy cliff face 100 feet above the prairie. He had discovered the T. rex later to be named after him, Stan.

Dinosphere's Stan is a cast of the original Stan in the collection of the Black Hills Institute.

You can learn more about Stan on the Black Hills Institute website.