The Story in a Skull — Microsoft Dinosaurs

The Story in a Skull

A dinosaur's skull is a treasure map — read it right and it tells you how the animal lived, what it ate, and how smart it was.

KindDinosaur science

All dinosaur skulls are built on the same basic plan, with hollows for the eyes, a space inside for the brain, channels and holes for nerves and blood vessels, and marks showing where the muscles for the jaws, tongue, and face were attached. By studying the teeth in the two skulls shown here, we know the owner of the skull on the left was a plant-eater, while the one on the right ate meat. By comparing skulls from other dinosaurs, and from reptiles and other animals alive today, we can make some good guesses about what the dinosaurs looked like.

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Airheads

Some dinosaurs had air pockets in their skulls, which presumably made their heads lighter and easier to move about on their long necks.

CompsognathusLike most theropods, Compsognathus had a lightweight skull that ended in a sharp snout. Large open spaces in the skull allowed powerful jaw muscles to move freely, and big eye sockets mean that this speedy hunter probably had large eyes.

CamarasaurusThis sauropod must have had a good sense of smell and perhaps keen eyesight as well, because it had huge nasal cavities and large eye sockets.

Musical Skulls

Some dinosaurs had odd-looking skulls with bony crests that may have been used to produce or amplify sounds.

LambeosaurusHadrosaurs were famous for their strangely shaped heads, and Lambeosaurus was no exception. This dinosaur had both a large crest and a backward-pointing spike on its skull. These strange structures enclosed hollow tubes that passed down to the dinosaur's nostrils, so it's a natural assumption that Lambeosaurus used these devices to make noise.

ParasaurolophusThe long hollow crest on this dinosaur's skull puzzled experts for years. At various times it was thought to be a snorkel for underwater swimming, a reserve air tank, or a nostril extension to enhance the sense of smell. Now scientists think that the tube was probably a resonator that allowed Parasaurolophus to hoot or bellow in a special way.

Skull Like a Crocodile

Baryonyx had an unusually narrow head for a dinosaur. The number of sharp teeth and the curiously curved line of the dinosaur's mouth give Baryonyx a profile that is remarkably similar to that of a crocodile. And, like a crocodile, this dinosaur is thought to have hunted and eaten fish.

Judging Eyesight and Intelligence

Most dinosaurs did not have very large spaces in their skulls for their brains. Does this mean they weren't very smart? Dinosaurs lived for millions of years, so they must have been intelligent enough to cope well with the world they lived in.

AllosaurusThe big sockets in the skull of Allosaurus probably indicate that the dinosaur had large eyes. Most of the other spaces in the skull seem to have been for weight reduction. Allosaurus probably did more eating than thinking.

Pea brainsStegosaurs are known for their tiny brains. Some people believe they had a second brain hidden in their hipbone area.

TroodonThis man-sized dinosaur had a large brain cavity in its lightweight skull. Its brain size, in combination with its large eyes, mean that Troodon was a keen hunter by day or night.

All in Our Heads

All animal skulls have similarities: they have eye sockets, nasal cavities, teeth, jawbones, and space for a brain. But you can tell from the overall shape of this skull that its owner didn't look much like a dinosaur!

Brain domeA human skull is more dome-shaped and bulging than any of our animal relatives, leaving ample room for a large brain. Are we smarter than all other animals on Earth?

Mobile jawsThe joint where the lower jaw joins the skull is remarkably mobile in humans. We can open and close our mouths, stick out our chins, and move our lower jaws from side to side. Many animals can only move their lower jaw up and down.

TeethHumans have several different types of teeth: incisors for cutting and snipping, canine teeth for piercing and tearing, and molars for crushing and chewing. This variety of teeth, combined with the flexibility of our jaws, allows us to eat almost any type of food.

Growing with Time

Just like humans, the shape of the dinosaurs' skulls changed as they grew older. Bumps and crests tended to become more pronounced as the dinosaur aged. Scientists use not only the size but also the proportions of a skull to determine if a dinosaur was an adult or a juvenile.

CorythosaurusThe crest of an adult Corythosaurus was noticeably larger than that of a juvenile dinosaur of the same type.

ProtoceratopsCompared to juveniles, adult Protoceratops had larger nose ridges, which they probably used to butt rivals. Adults also developed larger neck frills.

Frills and Muscles

A skull of a ceratopsian, or horned dinosaur, is distinctive not only for its horns but for the bony "frill" or collar that covered the dinosaur's neck. This frill made an impressive display to other dinosaurs, but its main purpose was to anchor the ceratopsian's powerful jaw muscles.

Heavy headThe skull of Triceratops can tell us a lot about the dinosaur's way of life. Its jaw was built to tackle very tough and fibrous plant matter, and was powered by large jaw muscles that were anchored to the neck frill. It used its narrow hooked beak to snip off plants, which it then sliced up with its sharp, scissor-like teeth. Triceratops used its horns not only for defense against predators, but also to head-wrestle with other dinosaurs of its own kind.

Hard-headed

The head dome of Pachycephalosaurus was made of solid bone and was nearly a foot thick! This dinosaur used its helmet-like skull to butt its rivals in much the same way that sheep and goats do today.

Head-butting contestsSuch contests among "bonehead" dinosaurs may have settled territorial disputes, or determined which dinosaur had the right to be leader of the herd, or which had the right to mate.

Wrong-headed

For many years, museums displayed the body bones of Apatosaurus with the skull of a relative named Camarasaurus. It was not until the 1970s the mix-up was discovered. The Camarasaurus's skull was removed and the proper skull was then placed on Apatosaurus's body.

More like thisExperts now agree that Apatosaurus had an elongated skull more similar to this one, which belongs to another relative, Diplodocus.

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Deinosuchus Compsognathus Saurolophus Baryonyx Troodon Life After Dinosaurs Protoceratops Triceratops Pachycephalosaurus Myths and Legends

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