Herbivorous dinosaurs are underrated. Much like animals in Africa, nearly everybody wants to see the giant carnivores - Tyrannosaurus rex, Allosaurus, Velociraptor, etc. - instead of the big plant eaters that can be just as spectacular. A few, however, break the mold; this is one of them.
"Hey, that's Triceratops, right?"
Not quite. Although Torosaurus ("wide-perforated lizard" or, mistranslated, "bull lizard") looks quite a lot like one of the most iconic herbivorous dinosaurs, the story is twisting the other direction. Triceratops and Torosaurus looked so similar that paleontologists were starting to suspect something.
All those Triceratops specimens you saw growing up were immature Torosaurus specimens. Yes, really.
An adult Torosaurus was one massive beast. It reached 25 feet (7.6 meters) from head to tail. The skull alone was the size of a compact car (8.5 feet/2.6 meters). The name Torosaurus probably came from the holes in its massive frill, but the common mistranslation of "bull dinosaur" is a bit more fun. Not all dinosaur names come from Latin; let us call the giant herbivore with pointy horns a bull.
Torosaurus was distinguished from Triceratops primarily by its size. Otherwise, that three-horned face looks almost exactly like good ol' Triceratops. After cross-examining lots of specimens, specifically a bunch found at Hell Creek, Montana, paleontologists finally came to the conclusion that Triceratops and Torosaurus were just different growth stages of the same dinosaur.
What does this mean? For one thing, either Triceratops or Torosaurus is going to go extinct. The Cretaceous was not big enough for the both of them; this discovery proves that dinosaur diversity was down during the time of T.rex and Triceratops. (Sorry, Stegosaurus fans, but they were from the Jurassic.) Low species diversity is never a good thing; don't let it happen to us.