Getting Around

People once thought that many dinosaurs were too heavy to live out of water and had to wallow in lakes, their long necks serving as snorkels. But careful studies have shown that all dinosaurs lived and walked on land. The biggest were four-legged with heavy club feet, so they probably moved slowly like elephants. Smaller two-legged dinosaurs were swifter and more nimble. The long-legged ornithomimids ("ostrich mimics") were probably the quickest, capable of sprinting at sustained high speeds.

Road runners

Perhaps no dinosaur outsprinted Gallimimus ("chicken mimic"), the largest ornithomimid. This tall, athletic animal might have run at 50 mph (80 kmh) - faster that the fastest racehorse. Gallimimus usually paced around slowly, snapping up seeds, insects, or small mammals, but it was always ready to dash off quickly if a predator appeared.

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Gallimimus skull

Gallimimus's skull resembled a bird's, with a long, flat, toothless beak and wide eye sockets. A ring of little bony plates protected each eye (a feature still seen in birds). The eyes faced

Run like an ostrich sideways, enabling

Gallimimus probably ran like an ostrich, using Gallimimus to spot enemies its powerful hindlegs to pound the ground in ^^ Toothless beak approaching from almost any long strides. Unlike an ostrich, though, it had a direction. The braincase held a long tail that acted as a rudder, keeping it balanced brain about the size of a golf ball if it had to make sudden turns to outwit a predator. (a little larger than an ostrich's).

getting around

Living in herds

Apart from fossil footprints, there is little direct evidence that dinosaurs lived in herds. But so many animals today live in groups - from schools of fish to prides of lions - that paleontologists (fossil experts) think some dinosaurs probably did so, too. With more eyes and ears on the alert, it is easier for a herd to spot predators and find food. Gallimimus lived in a desert and may have had to travel long distances in search of food or water. Perhaps herds

Muscular tail

Intestines

S-shaped neck Scientists can tell this

Stomach ^^^ dinosaur was built for

Lungs Heart speed by comparing

Fossil finds

Muscular tail

Intestines

Thigh bone. Shin_

S-shaped neck Scientists can tell this

Stomach ^^^ dinosaur was built for

Lungs Heart speed by comparing animals. The chief clues are its lightly built body and ^^^ /- long legs and feet. Gallimimus had shins longer than its Rib thighs, a hallmark of fast sprinters like gazelles. Inside, it probably had a heart, lungs, and digestive organs like a bird's. We can guess this because birds are the closest living relatives of Gallimimus.

Fossil finds

Gallimimus

248 205 144

Million years ago

248 205 144

Million years ago

Cloaca

Ankle

Foot

Thigh bone.

Shin bone

Ankle joint

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