Easily the most famous dinosaur that ever lived, Tyrannosaurus Rex is a case study in how much we know--and how much we don’t know--about how dinosaurs behaved millions of years ago. For example, while we have a pretty good idea what T. Rex looked like, we’re still not sure whether it actively hunted its food, whether it was warm- or cold-blooded (or something in between), or even whether it could run faster than a little old lady on a three-speed bike.
Tyrannosaurus Rex: The Early Years
The first, fragmentary fossils of Tyrannosaurus Rex were discovered by the famous paleontologist Edward Drinker Cope (with Othniel. C. Marsh, one of the participants in the notorious 19th-century Bone Wars) in South Dakota in 1892. Drinker promptly named his find Manospondylus Gigax, which translates roughly as “giant thin vertebra”—and who knows how history might have changed if that name had stuck.
Fortunately, a succession of more complete fossil finds shortly after the turn of the century (by Barnum Brown, the assistant curator of the American Museum of Natural History) spared the king of dinosaurs from being saddled with the plebeian name Manospondylus. In 1905, museum president Henry Fairfield Osborn officially dubbed the species Tyrannosaurus Rex, Greek for “tyrant lizard king.”
The Tyrannosaur Family Grows
Technically, Tyrannosaurus Rex is properly referred to by its full name, because paleontologists have since discovered the fossils of numerous related species, from various parts of the world, which all fall under the category of tyrannosaurs, genus Tyrannosaurus. Other tyrannosaur discoveries--including Gorgosaurus, Albertosaurus and Appalachiosaurus--proved different enough from these various Tyrannosaurus species to merit being assigned to their own genera.
A brief word about another genus that's often included in this list, Nanotyrannus (literally, “tiny tyrant.”) It’s still a matter of some dispute whether this dinosaur, which was identified from a single fossilized skull found in the 1940’s, represents a genuinely new species of tyrannosaur or was simply an unfortunate T. Rex juvenile who died young. That’s the problem with investigating dinosaurs that died out tens of millions of years ago!
A Girl (or Boy) Tyrannosaurus Rex Named Sue
The most spectacular Tyrannosaurus Rex discovery to date was made by the (then) amateur paleontologist Sue Hendrickson, who unearthed a near-complete Tyrannosaurus Rex skeleton in South Dakota in 1990. Named “Sue” in Hendrickson’s honor, this individual apparently perished at the age of 28 from a bite to the head (which counts as natural causes in Cretaceous times), making it the oldest T. Rex yet found. (By the way, don’t let the name fool you—it’s unknown whether Dinosaur Sue was male or female, though paleontologists now believe that female tyrannosaurs tended to be bigger than males.)
Proving that no good T. Rex deed goes unpunished, Hendrickson spent the next few years immersed in legal proceedings pertaining to Sue’s ownership--kind of a dinosaur custody battle. It was finally determined that Sue’s bones belonged to the person who owned the piece of land where she was found, and in 1997 the remains were auctioned off to Chicago’s Field Museum of Natural History for $8 million, a dinosaur record at the time.
So Many Tyrannosaurus Rex Questions…
In a way, the popularity of Tyrannosaurus Rex has been both a blessing and a curse for paleontologists. On the plus side, any scientist who makes a major discovery about T. Rex behavior or physiology is sure to land herself front-page headlines around the world. On the minus side, people don’t like it when their idols are tampered with--especially if a supposedly fearsome, unstoppable dinosaur is shown to be, well, kind of a wimp, or even (heavens forfend) covered with feathers.
For example, nothing gets a Tyrannosaurus Rex fan’s blood boiling like the theory that T. Rex scavenged for its food rather than hunting it down, or that this dinosaur was slower than a New York City bus during rush hour. No matter what the experts say, though, you can be sure that Hollywood will go on portraying Tyrannosaurus Rex the old-fashioned way--as the perpetually grumpy, hungry, fleet-footed king of the dinosaurs.