Dinosaurs galore!

Make no bones about it—on today’s etymological dig, we’re uncovering the origins of dinosaur names!


Let’s start with “dinosaur” itself. This word was coined by anatomist Sir Richard Owen following the first recognized discoveries of dinosaur fossils in the 1820s. It combines the Greek words deinos (“monstrous” or “fearful”) and sauros (“lizard”)—an understandable reaction to finding such extraordinary creatures!

Tyrannosaurus rex

As for the T. rex, he’s the “tyrant lizard king”! (Turannos is the Greek word for “tyrant,” while rēx is the Latin word for “king.”) It’s an apt name for what was long thought to be the largest carnivorous dinosaur, which could grow to an estimated 39 feet (12 meters) in length and 10 metric tons in weight. The T. rex also had jaws that could open four-feet wide and were filled with 60 eight-inch-long serrated teeth—certainly the sort of monstrous traits fit for a tyrant king!

Brontosaurus and Apatosaurus

The Brontosaurus may be one of the best-known dinosaurs today, but it’s had a bit of an identity crisis over the years. Let’s start in 1877, when paleontologist O. C. Marsh named a specimen he’d found Apatosaurus. The Greek word apatē means “untruth” or “deceptive,” though what was “deceptive” about this dino is unclear. It may be that Marsh initially thought he’d found a different dinosaur.
Fast-forward two years, when Marsh discovered the bones of another dinosaur. He gave this huge creature the name Brontosaurus, meaning “thunder lizard." (Brontē is the Greek word for “thunder.”) There was just one small problem: the Apatosaurus and the Brontosaurus were later determined to be the same dinosaur. Whoops!
The first published name for an organism is the one that must be used scientifically, so this dinosaur is officially an Apatosaurus. In the court of public opinion, though, Brontosaurus steals its thunder and experts have begun to agree—there have been recent arguments that the skeletons of both dinosaurs are different enough that they should be classified separately.


This dino had a pair of horns above its eyes and a single horn on its nose, and its name reflects that. "Triceratops" is made up of three parts: the prefix “tri-” (“three”) and the Greek words keras (“horn”) and ōps (“eye” or “face”). So its name roughly means “three-horn face” or “three-horn eye.” A three-part name for the dinosaur with the three-horn face!


The Velociraptor was only about six feet in length, but it offset its height disadvantage with deadly claws and great speed, traits reflected in the meaning of its name. The Latin word vēlōx means “fast” (see also: “velocity”), while raptor in Latin means “one who seizes” (which is why we also use “raptor” to mean “bird of prey”). They are also classed as “theropods,” which comes from Greek and roughly translates as “beast feet.” Eek.


Raise the roof for the “roof lizard”! Yep, that’s the Stegosaurusstegos is the Greek word for “roof,” likely referring to the large bony plates that lined this dinosaur’s back. The purpose of these plates is not definitively known, but one theory is that they helped stegosauruses to recognize each other. ’Sup, stego bro!


If it flies like a bird and has hollow bones like a bird… well, in this case, it’s not a bird. Pterodactyls (what most people call pterosaurs) actually developed completely separately from birds, even though they are best known for their ability to fly. This trait even gives them their name: pterodactyl literally means “winged finger,” referring to how its wings attached to the fourth finger of each hand. (Pteron is the Greek word for “wing” and daktulos is the Greek word for “finger.”) Pterodactyls also had a unique “pteroid” bone that helped to support their wings. Non-birds of a feather flock together?

The Mighty Thesaurus rex!

What’s every dictionary editor’s favorite dinosaur? Why, the magnificent, exalted, resplendent Thesaurus, of course! (Though we must admit that this “saurus” comes from the Greek thēsaurós, meaning “treasury.”) It’s possible that we were so preoccupied with whether or not we could, we didn’t stop to think if we should....
Don’t let these facts go the way of the dinosaur—share ’em!
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