Not only are Triceratops and Tyrannosaurus Rex the two most popular dinosaurs that ever lived; they were also contemporaries, prowling the plains, creeks and woodlands of late Cretaceous North America, about 65 million years ago. It's inevitable that a hungry T. Rex and a wary Triceratops would have occasionally crossed paths; the question is, which of these dinosaurs would emerge victorious in hand-to-hand (or, rather, claw-to-claw) combat? (Don't be afraid to express your opinion about how this battle turns out, and see more dinosaur death duels.)
In the Near Corner - Tyrannosaurus Rex, the King of the Dinosaurs
T. Rex doesn't really need an introduction, but let's provide one anyway. This "tyrant lizard king" was one of the most fearsome killing machines in the history of life on earth; full-grown adults weighed in the neighborhood of seven or eight tons and were equipped with massively muscled jaws studded with numerous, sharp, shearing teeth. For all that, though, there remains some disagreement about whether T. Rex actively hunted for its food, or scavenged already-dead carcasses.
Advantages. According to recent studies, T. Rex chomped down on its prey with a force of two or three tons per square inch (compare that with 175 pounds or so for the average human). Judging by the size of its olfactory lobes, T. Rex also had a well-developed sense of smell, and its hearing and vision were probably better than average by late Cretaceous standards. One unconventional weapon may have been T. Rex's bad breath; rotting chunks of meat stuck in this theropod's teeth could have transmitted fatal infections to any animal lucky enough to survive an initial bite.
Disadvantages. As "arms races" go, T. Rex was a hands-down loser; this dinosaur's arms were so short and stubby that they would have been nearly useless in a fight (except, perhaps, to clutch near-dead or dying prey close to its chest). Also, despite what you've seen in the movies, T. Rex probably wasn't the swiftest dinosaur on the face of the earth; an adult running at full speed might not have been a match for a five-year-old kindergartner on training wheels.
In the Far Corner - Triceratops, the Horned, Frilled Herbivore
All theropods (the family of meat-eating dinosaurs that includes T. Rex) looked vaguely alike, but Triceratops cut a more distinctive profile. This dinosaur's head was one-third the length of its entire body--some preserved skulls measure well over seven feet long--and it was adorned with an expansive frill, two dangerous, forward-facing horns, and a smaller protrusion on its snout. An adult Triceratops weighed about three or four tons, or half the size of this dinosaur's T. Rex nemesis.
Advantages. Did we mention those horns? Very few dinosaurs, carnivorous or otherwise, would have cared to be gored by Triceratops, though it's unclear how useful these weapons could have been in the heat of combat. Like many large plant-eaters of its day, Triceratops was built low to the ground, endowing it with a stubborn center of gravity that would have made this dinosaur very difficult to dislodge if it chose to stand and fight.
Disadvantages. The plant-eating dinosaurs of the late Cretaceous period weren't the smartest bunch; as a general rule, carnivores tend to have more advanced brains than herbivores, meaning Triceratops would have been far outclassed by T. Rex in the IQ department. Also, while we don't know how swiftly T. Rex could run, it's a sure bet that even the pokiest adult was faster than the lumbering, four-legged Triceratops, which didn't need to pursue anything speedier than a giant fern.
Let's assume for the moment that this particular T. Rex is tired of scavenging its food and wants a hot lunch for a change. Catching a whiff of a grazing Triceratops, it charges at top speed, ramming the herbivore in its flank with its massive head. Triceratops teeters, but manages to stay on its elephant-like feet, and it wheels its own head around in a belated attempt to inflict damage with its horns. T. Rex lunges for Triceratops' throat, but collides with its massive frill instead, and both dinosaurs topple awkwardly to the ground. The battle hangs in the balance; which combatant will get up on his feet first, either to run away or to lunge in for the kill?
And the Winner Is...
Triceratops! Hobbled by its puny arms, T. Rex requires a few precious seconds to lever itself off the ground--by which time Triceratops has lumbered up on all fours and darted off into the brush. Somewhat embarrassed, T. Rex finally gets back up on its own two feet, and stomps off in search of smaller, more tractable prey--or perhaps the nice carcass of a recently deceased hadrosaur.