Alamosaurus: Thirty million years after sauropod dinosaurs had become extinct in what is now North America, the sauropod Alamosaurus reappeared there. Paleontologists believe their ancestors may have migrated from South America across a new land bridge that joined the two continents.
Name: Alamosaurus ("Alamo lizard")
Length: 69 feet (21 meters)
Weight: 30-33 tons
Time: 74-65 million years ago (Late Cretaceous)
Place: New Mexico, Texas, Utah
Diet: plant-eater (herbivore)
