Amargasaurus (named for La Armaga, in Argentina, where the fossil was found) had spines along the back of its neck, back, and tail, possibly forming a sail that could have been used to regulate its body temperature, ward off predators, or attract mates. The plant-eating sauropod was about 33 feet (10 meters) long and weighed as much as five tons (5,000 kilograms). It may have traveled in herds.

Born in Cuba and educated in Spain, Luis Rey's dinosaur art has been featured in numerous exhibitions and books. He bases his work on rigorous anatomical studies. Check out Rey's Web site to see more of his work. Find out more about his books A Field Guide to Dinosaurs, published in the U.S. by Barron's Educational Series, and available from all bookstores, or direct from the publisher.

Go back to the story "Bizarre Dinosaurs": Go>>

More dinosaur stories from: National Geographic News >>