Tyrannosaurus

Type Species: Tyrannosaurus rex
Classification: Dinosauria - Saurischia - Theropoda - Tetanurae - Tyrannosauridae
Time Period: late Cretaceous
Location: North America
Diet: Carnivore

From storybooks to kids' drawings, to professional art and worldwide cinematic hits, Tyrannosaurus rex is worshiped and revered as the titan of the dinosaur world. Its very name means "tyrant lizard," and media harps upon this fact. Remains of more than fifty skeletons have been discovered throughout North America, in Wyoming, Colorado, Texas, South Dakota, and as far north as Alberta, Canada. Tyrannosaurus was one of the largest carnivores of dinosauria (the current title of carnivorous heavyweight champ goes to Spinosaurus, and Tyrannosaurus ranks tenth). Although he's lost the championship title, Tyrannosaurus remains an imposing figure:

"What are we to make of those scrawny forearms?" The first Tyrannosaurus skeletons were incomplete, and paleontologists speculated that it had larger three-fingered arms like that of Allosaurus. When complete skeletons were found, including the world-famous "Sue", it became apparent that Tyrannosaurus did indeed have (what appeared to be) scrawny arms. Biomechanical analyses of the arms, however, imply they may not have been that scrawny after all. The cortical bones in the arm were thick, implying an ability to withstand intense pressure and heavy loads; the bicep muscles would've been able to lift 439 pounds. I don't know any human who can do that, and if humans were as large as Tyrannosaurus, this dinosaur would still be able to lift 3.5 times as much weight as a human would. These arms weren't scrawny at all; despite their size, they could be used to grapple and hold prey while the jaws went to work. It's been said that what matters isn't size but how you use it; Tyrannosaurus' arms are a Case Study of this fact. 

fighting over a carcass? or defending a kill? Read more below!

An ongoing debate regarding Tyrannosaurus has to do with its diet: "Was it a scavenger or a predator?" Some have argued that because of its short forearms and awkward build, it wouldn't have made a good predator; if it fell, for instance (as might happen in a contest against an armored herbivore), it would have a hell of a time getting back to its feet. For a time the evidence lie with those arguing for a scavenging diet, but lately this has gone out-of-style. Tyrannosaurus seems built for hunting: its eyes face forward and not to the side as with most carnivorous dinosaurs, allowing for depth and distance to be gauged; the strong yet lightweight skull made for a formidable attack; and its muscular jaw, with specialized hinges that allowed the bottom jaw to be lowered unusually low to take in large chunks of meat, could've served as a "grappling hook" against struggling prey. Its legs were extremely muscular; at a walking pace, it could move close to five miles an hour, and it could top thirty miles per hour in a brisk jog. The nail in the coffin of the Pro-Scavengers came in 2013; up to that point, there were hints here-and-there that Tyrannosaurus was a hunter: bones with bite marks, broken teeth near skeletal remains, and foot tracks indicating pursuits. In 2013, however, a remarkable find was made: a Tyrannosaurus rex tooth was found embedded in the tailbone of a hadrosaur. The hadrosaur's tailbone had healed over the tooth, indicating that it had escaped its predator to live another day. 

an Anatotitan Rodeo!