The Dead Zoo: Triceratops
Ol' three-horned face wasn't as friendly as we'd like to think.
It couldn’t have been because of Uncle Beazley. That dinosaur was before my time, and I didn’t encounter him at the National Zoo until after I was already grown up. Jurassic Park couldn’t have been it, either. I wish I could have given the sick Triceratops a hug just like Alan Grant did, but I was already ten before I dragged my family to see the epic cinematic dinosaurs. There must have been something else.
Maybe it’s because Triceratops was the natural counterpoint to Tyrannosaurus. The two could be cast as mortal enemies, forever locked in battle, but, as a kid, I felt it was more a choice between the aggressive and the gentle. Triceratops gave off a more laid-back vibe, happy to let you clamber atop its scaly back as it munched on ferns. At five years old, when I was convinced I could dig upfossils in my grandparents’ backyard, I liked to think that maybe I could find some Triceratops eggs and one would hatch so I would have a big, friendly, dinosaurian friend to ride to school. Those horns weren’t offensive weapons, a far as I was concerned. They were only for decoration and so that ravenous tyrants wouldn’t get any ideas. The composite skeleton at the American Museum of Natural History I saw around that age wasn’t braced for combat, but was simply crouching down to grin at all the kids who had come to admire the great three-horned face.
If I had been granted my childhood wish, however, I probably would have been trampled and gored. Herbivores know they’re made of meat and seem grumpy enough about it to be distrustful of strange creatures ambling too close. Just ask any Yellowstone ranger. The biggest point of human-wildlife conflict in the park doesn't involve grizzly bears or wolves, but tourists who get too close to bison and end up being stomped and thrown like ragdolls. Horned herbivores are not your friends, and, as far as Triceratops goes, we know this dinosaur wasn’t as genial as I liked to believe.
Paleontologist Andy Farke figured it out, and it all started with Triceratops toys. It really was an ingenious example of fossil detective work. For decades paleontologists had speculated about whether or not Triceratops used its trio of horns in combat against each other. But how to test it? Without a way to directly observe the Cretaceous, answering the question seemed impossible. That is, until Farke turned to scale models of Triceratops skulls to investigate the range of horn-locks available to the dinosaur. The angles and arrangement of the horns allowed several possibilities, predicting contact between horns and other skull bones at the cheek and lower parts of the shield-like frill jutting from the back of the head.
That’s exactly where damage showed up on real Triceratops skulls. In that first study, as well as a follow-up with paleontologists Ewan Wolff and Darren Tanke, Farke found lesions on Triceratops skulls right where the models predicted they would show up if the dinosaurs really were locking horns in life. These weren’t bite marks or signs of other damage. The most likely scenario was that the marks were created by ornery Triceratops ramming their massive heads together and struggling. (A dinosaur with a very different horn arrangement, Centrosaurus, didn’t show this damage, suggesting that they confronted each other in a different and perhaps less-violent way.) Watch elk or pronghorn joust and you can get a taste of what Triceratops did 68 million years ago.
Why Triceratops fought, no one knows. The duels could have been over territory, access to mates, or something totally unknown to us, like partisan dinosaurian politics. Nevertheless, those signs of damage are clues about the habits of living animals and remind us that dinosaurs are so much more than piles of old bones. Each of their ancient elements has stories to tell, even if they’re not always the stories we most want to hear. It would break my heart, but, if genetic engineering or a time travel slip ever brought me face to face with a live Triceratops, I’d try to admire the grumpy saurian from beyond the range of those terrible horns.
About the author
Brian is the author of My Beloved Brontosaurus, Written in Stone, and other books. He also writes the Laelaps blog for Scientific American and publishes on fossil discoveries in outlets from Smithsonian to the Wall Street Journal.