10 Cool Facts About Triceratops
With its three horns and its giant frill, Triceratops is one of those outsized dinosaurs that can be spotted from a mile away, either in the wild or in a collection of figurines. But how much do you really know about this horned, frilled behemoth, other than that its plastic model looks cool posed next to your scale-model Stegosaurus and Tyrannosaurus rex?
1. Triceratops Had Two Horns, Not Three
The name Triceratops is Greek for "three-horned face," but the fact is that this dinosaur had only two genuine horns; the third, much shorter "horn" on the end of its snout was actually made from a soft protein called keratin, the kind found in human fingernails, and wouldn't have been of much use in a tussle against a hungry raptor. (By the way, paleontologists have identified the remains of a two-horned dinosaur called Diceratops, but these may represent a juvenile growth stage of Triceratops; see slide #8.)
2. The Skull of Triceratops Was One-Third the Length of its Entire Body
Part of what makes Triceratops such a recognizable dinosaur is the enormous size of its skull, which, with its backward-pointing frill, could easily attain a length of over seven feet. Unbelievably, the skulls of other ceratopsians, such as Centrosaurus and Styracosaurus, were even bigger and more elaborate, most likely as a result of sexual selection, as males with bigger heads were more attractive to females during mating season and passed down this trait to their offspring. Appropriately enough, the biggest skull of all horned, frilled dinosaurs belonged to the allusively named Titanoceratops.
3. Triceratops Was on the Lunch Menu of Tyrannosaurus Rex
As any dinosaur fan knows, Triceratops and Tyrannosaurus rex occupied the same ecosystem (the marshes and forests of western North America) at the same time (about 65 million years ago, just before the K/T Extinction that wiped out the dinosaurs). Therefore, it's reasonable to assume that T. rex occasionally preyed on Triceratops, though only Hollywood special-effects wizards know how it managed to evade this plant-eater's sharp horns, assuming it was hungry enough to take the risk.
4. Triceratops Had a Hard, Parrot-Like Beak
One of the lesser-known facts about horned, frilled dinosaurs like Triceratops is that they possessed bird-like beaks, which they used to clip off hundreds of pounds of tough vegetation (including cycads, ginkgoes and conifers) every day. Triceratops also had "batteries" of shearing teeth embedded in its jaws, of which a few hundred were in use at any given time. As one set of teeth wore down from constant chewing, they would be replaced by those from the adjacent battery, a process that continued throughout this dinosaur's lifetime.
5. The Ancestors of Triceratops Were the Size of House Cats
By the time ceratopsian dinosaurs reached North America, during the late Cretaceous period, they had evolved to the size of cattle--but their distant progenitors were small, occasionally bipedal, and slightly comical-looking plant-eaters that roamed the expanse of central and eastern Asia. One of the earliest identified ceratopsians is the late Jurassic Chaoyangsaurus, which weighed 30 pounds soaking wet and had only the most rudimentary hint of a horn and frill; other early members of the horned, frilled dinosaur family may have been even smaller!
6. Triceratops Used its Frill to Signal Other Members of the Herd
Why did Triceratops have such a prominent frill? As with all such anatomical structures in the animal kingdom, this thin flap of skin scaffolded on solid bone likely served a dual (or even triple) purpose, but the most probable explanation is that it was used to signal other members of the herd. A brightly colored frill, flushed pink by the numerous blood vessels lying under its surface, may have signaled sexual availability or warned about the approach of a hungry Tyrannosaurus rex; the frill may also have had some temperature-regulation function, assuming that Triceratops was cold-blooded.
7. Triceratops May Be the Same Dinosaur as Torosaurus
In recent years, many dinosaur species have been reinterpreted as "growth stages" of already-named genera. This appears to be the case with the two-horned Torosaurus, which some paleontologists argue represents the remains of unusually long-lived Triceratops males whose frills continued to grow into old age. (Despite what you may have heard, though, it's not true that Triceratops will have to change its name to Torosaurus, the same way Brontosaurus suddenly became Apatosaurus when no one was looking.)
8. Triceratops Was Once Mistaken for a Giant Bison
In 1887, the famous American paleontologist Othniel C. Marsh examined a partial Triceratops skull, complete with horns, discovered in the American west—and promptly and incorrectly assigned the remains to the grazing mammal Bison alticornis, which didn't evolve until tens of millions of years later, long after the dinosaurs had gone extinct. Fortunately for his reputation, Marsh quickly reversed this embarrassing blunder, though some of his other mistakes (pertaining to other dinosaurs) weren't so easily erased. (See more about the discovery and naming of Triceratops.)
9. Triceratops Fossils Are Prized Collector's Items
Because the skull and horns of Triceratops are so large, so distinctive and so resistant to natural erosion—and because so many fossil specimens have been discovered in the American west—museums and individual collectors tend to dig deep to enrich their collections. The most famous recent example is Triceratops Cliff, purchased for $1 million in 2008 by a wealthy dinosaur fan and donated to the Boston Museum of Science. Unfortunately, the hunger for Triceratops bones has also resulted in a thriving grey market, as unscrupulous fossil-hunters try to poach and sell this dinosaur's remains.
10. Triceratops Lived Up to the Brink of the K/T Extinction
The fossil remains of Triceratops date to the very end of the Cretaceous period, only slightly before the meteor impact that killed the dinosaurs. By this time, paleontologists believe, the pace of dinosaur evolution had slowed to a crawl, and the resulting loss of diversity (combined with various other factors) virtually guaranteed their quick extinction. Along with its fellow plant-eaters, Triceratops was doomed by the loss of its accustomed vegetation, as clouds of dust circled the globe in the wake of the K/T catastrophe and blotted out the sun.