Palentologist Fernando Novas poses with a bone from Puertasaurus reuili, a giant plant-eating dinosaur. The dorsal (back) vertebra, about 3.5 feet (1 meter) tall and 5.5 feet (1.7 meters) wide, is one of four fossils from the species unearthed in Argentina's Patagonia region.

Only another titanosaur, Argentinosaurus huinculensis, rivals Puertasaurus in size, scientists say. Argentinosaurus was also found in Argentina's Patagonia region and dates back to 90 million years ago.

• More Photos in the News
• Today's Top 15 Most Popular Stories
• Free Email Newsletter: "Focus on Photography"