The stegosaurus was an armored dinosaur that lived about 150 million years ago. It had a heavily rounded back, short forelimbs, head held low to the ground and a stiffened tail held high in the air. The double plates along its back were most likely used for defense and may also have regulated its temperature. Stegosaurus weighed about 6,800 pounds and was 9 feet tall.
The name from Greek means 3 horned face. This dinosaur was about 30 feet long, 10 feet tall and weighed 4 to 6 tons. Stout limbs supported its girth but it was unlikely the dinosaur could move very quickly. Like a modern-day rhinoceros, it probably spent much of its time grazing on plant matter.
Pteranodon is a genus of pterosaurs which included some of the largest known flying reptiles with wingspans over 6 meters. They lived about 80 million years ago in North America in present day Kansas, Alabama, Nebraska, Wyoming, and South Dakota.