Ultrasaurus was a large sauropod dinosaur that lived during the Early Cretaceous Period in what is now South Korea. A holotype specimen of Ultrasaurus from the Jurassic period in Colorado turned out to be a mixture of Supersaurus and Brachiosaurus, meaning it was not even a true genus. Ultrasaurus is now just an alternate name for the dinosaur officially known as Supersaurus.
The Ultrasaurus are located in a section called Ultrasaur Lagoon. They spend most of their in the water, eating aquatic plants. One Ultrasaurus is an adult, the other a smaller infant. They share their section with Psittacosaurus.