Triceratops is on most peoples' short lists of the most popular and recognizable dinosaurs, but there's a lot about this beast that's still shrouded in mystery. Here are 10 things you may (or may not) have known about Triceratops. (See also a gallery of Triceratops pictures.)
1. The name "Triceratops" is a bit misleading.
Triceratops is Greek for "three-horned face," but this dinosaur had only two real horns; the third, much shorter "horn" on its snout was actually made from soft proteins, and wouldn't have been much use in a tussle. (By the way, fossils have been discovered of a related, two-horned dinosaur called Diceratops, but some paleontologists think this was really a growth stage of Triceratops.)
2. Triceratops was on T. Rex's lunch menu.
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). 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. (See Tyrannosaurus Rex vs. Triceratops - Who Wins?)
3. Triceratops' skull 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 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.
4. The paleontologist who named Triceratops thought it was an ancient bison.
In 1887, the famous paleontologist Othniel C. Marsh examined a partial Triceratops skull, complete with horns--and promptly assigned the remains to the grazing mammal Bison alticornis, which didn't evolve until tens of millions of years later. Fortunately for his reputation, Marsh quickly reversed the error. (See more about the discovery and naming of Triceratops.)
5. 65 million years ago, Triceratops was one of the last dinosaurs standing.
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, dinosaur evolution had slowed to a crawl, and the resulting loss of diversity virtually guaranteed their quick extinction. Along with other herbivores, Triceratops was doomed by the loss of its accustomed vegetation, as clouds of dust circled the globe in the wake of the K/T meteor impact.
6. Triceratops wasn't the only dinosaur of its kind.
The ceratopsians--"horned faces"--were a large family of herbivorous dinosaurs, of which Triceratops is only the most notable genus. Oddly enough, the ceratopsians of the late Cretaceous period are believed to have evolved from the much smaller (and probably bipedal) Psittacosaurus, which had a distinctly parrot-like head, and which itself had even tinier forebears dating all the way back to the end of the Jurassic period.
7. Torosaurus may have been a species of Triceratops.
Recently, several dinosaur genera have been reinterpreted as different "growth stages" of existing species. This appears to be the case with specimens of the two-horned ceratopsian Torosaurus, which some paleontologists argue are 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 change its name to Torosaurus, the way Brontosaurus changed its name to Apatosaurus.)
8. Triceratops bones sell for big bucks.
Because the skull and horns of Triceratops are so distinctive and resistant to natural erosion--and because so many specimens have been discovered--museums and individual collectors are willing 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.
9. No one knows how Triceratops used its horns.
For generations, paleontologists assumed that Triceratops evolved its horns for one reason--to keep hungry raptors and tyrannosaurs at bay. Now, though, some experts believe these horns may have been primarily a sexually selected characteristic: that is, male Triceratops with bigger, sharper horns had a better chance of mating with available females.
10. Next to T. Rex, Triceratops is the most popular movie dinosaur.
Tyrannosaurus Rex always seems to have the starring role, but any dinosaur movie worth its Mesozoic salt is sure to include a Triceratops or two. The most famous recent example is the first Jurassic Park, with its sick, scene-stealing Triceratops laying prostrate next to an enormous pile of its own poop. (Oddly, though, the 2013 release Walking with Dinosaurs: The 3D Movie spotlights the much less well-known ceratopsian Pachyrhinosaurus.)