Page 64 - The Dinosaur Book and Other Wonders of the Prehistoric World (DK-Smithsonian)

Prosauropods

Fossils of this giant
prosauropod were
found in La Rioja
Province, Argentina.

Riojasaurus Set within its jaws were small,
leaf-shaped teeth that had serrated
edges to help slice through vegetation.
Massospondylus

The long, flexible
neck was well
adapted for browsing
on tree foliage.

The strong back
legs supported all of
the dinosaur’s weight,
leaving its hands free.

Seitaad

The remains of Seitaad, A heavy tail balanced the
meaning “sand monster” in the dinosaur’s body at the hips,
Navajo language, were found enabling it to reach up
near the Grand Canyon. into the trees easily.

Soon after the evolution of the first them reach into trees, but their heads stayed
dinosaurs in the middle Triassic (around relatively small. One of the earliest, Saturnalia,
230–225 million years ago), dinosaurs was only about 6 ft (1.8 m) long, but its relatives
began to diversify into species with were to get a lot bigger; by the late Triassic,
different lifestyles. Some specialized in eating Riojasaurus was about 33 ft (10 m) long and
62 plants. They evolved long necks that helped weighed as much as an elephant. These

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