Among dinosaurs, the biggest of the big is Argentinosaurus. This long-necked, puny-headed creature is a member of a group of giants called sauropods. This particular extinct creature measured as much as 140 feet (43 meters) long and weighed up to 90 tons (82 metric tons). 

Beyond inspiring awe, a creature of these proportions inspires all sorts of questions: Why and how did these dinosaurs, which started out relatively small, become so big? How did they feed and maintain their large bodies? A new exhibit at the American Museum of Natural History in New York City explores the mysteries surrounding their enormity.

The exhibit is dominated by a model of Mamenchisaurus, a smaller relative to Argentinosaurus. The skin is peeled back on half of the model to allow a peek into the animal's physiology. On the left side of the abdomen, projected images show body processes, such as the path of fresh air into the lungs and a birdlike system of air-storage sacs.