Protoceratops — Microsoft Dinosaurs

Protoceratops

pro-toe-SER-a-tops name means “First-horned face”

The first horned face — a pint-sized dinosaur that hatched in family nests and proved that dinosaurs laid eggs.

KindDinosaur Period Late Cretaceous Diet Herbivore

Although it did not have true horns, this dinosaur was named Protoceratops, or "first horned face," because it is thought to be one of the first horned dinosaurs, called ceratopsians. Fossils of baby, juvenile, and adult Protoceratops have been found close together, which suggests they may have lived in family groups. This family scene shows baby Protoceratops at various stages—some hatching, some taking their first steps, and some struggling to get out of the sand.

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Nest-Building Dinosaurs

The eggs in this sandy nest came from Protoceratops. Several mothers may have laid their eggs in a circle in the same nest. They would then have covered the eggs with earth or sand to protect them until they hatched.

Egg assortmentFossilized dinosaur eggs have been found in many sizes. The largest dinosaur egg was about twelve inches long. The eggs of Protoceratops were only about eight inches long.

The Smallest Horned Dinosaur

Here is Protoceratops with some of its horned relatives. As you can see, not all ceratopsians were as small as Protoceratops. All ceratopsians lived during the Late Cretaceous period, however, Protoceratops is thought of as more primitive than its later relatives you see here.

CentrosaurusThis dinosaur had two spikes that curved forward to protect the "windows" in the dinosaur's skull.

ProtoceratopsThis adult Protoceratops looks like a baby compared to its horned cousins!

ChasmosaurusThe frill of this dinosaur stretched halfway along its back. When the animal lowered its head, the tall frill would have made an impressive display.

StyracosaurusThis dinosaur's name means "spiked lizard." It had six long spikes pointing from its neck frill.

Different Frills for Different Ages

Ceratopsians had hooked beaks, thin sharp teeth, and massive jaw muscles that enabled them to tackle very tough plants. As Protoceratops dinosaurs grew, the shape of their skulls changed.

Skulls through the agesAs shown here, adults had higher nose ridges and larger frills than younger Protoceratops. The frills served as anchor points for the dinosaurs' powerful jaw muscles, as well as for protection.

A Frilly Face

Dinosaurs have very different faces. When you look at Protoceratops face to face with other dinosaurs, you see the predominance of its frill and beak.

StegosaurusAlthough this dinosaur's body was large, it had a small head.

EudimorphodonThis toothy mouth belonged to a flying reptile, not a dinosaur.

EuoplocephalusThis dinosaur's face looks as if it was chiseled out of stone.

A Hard Egg to Crack

Eggs laid by Protoceratops were more elongated than those of birds. Found in Mongolia in the 1920s, Protoceratops eggs were the first evidence that dinosaurs laid eggs in nests. The tough shells, with their coarse pimply surfaces, protected a liquid interior in which the baby developed. The shells had tiny tubes leading from inside the eggs to the outside air, allowing the dinosaur embryos to breathe.

Quail eggThis quail egg contains a baby that would become a tiny bird, while the Protoceratops egg contained a creature that grew as big as a car. Dinosaur eggs couldn't be as massive as you might expect—a gigantic egg would require a shell so thick that air couldn't get in and the baby couldn't get out.

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Faces from the Past

Source: Microsoft Dinosaurs (1993) CD-ROM. Text liberated from original screen art; images & audio restored from disc. Original media is Microsoft/supplier copyright — non-commercial educational preservation. Credits & Acknowledgements