Alamosaurus lived around 70–66 million years ago, in the very final chapter of the Age of Dinosaurs. A titanosaur, it reached up to 30 meters (98 feet) in length, making it the largest known dinosaur from North America and one of the heaviest animals to ever walk the planet. Its long neck and powerful body allowed it to graze on a wide variety of vegetation, from low shrubs to treetops. Despite its size, Alamosaurus faced threats from predators like Tyrannosaurus rex—but only the youngest.