Ultrasaurus Characteristics

Ultrasaurus was enormous and measured 90 feet (27 metres) in length. Its tall front legs reached a height at the shoulder of perhaps 25 feet. It was heavy-bodied and weighed around 80 tons, twice as much as other sauropods. Ultrasaurus had a extremely long neck which could reach nearly 60 feet above the ground and a small head. Ultra saurus was quadrupedal and walked on all 4 thick, trunk-like legs. Its fore legs were longer than its hind legs which gave it a giraffe-like body structure. The tail was small and short compared to the tails of other diplodocids.

Ultrasaurus was a herbivore and ate prehistoric plant material. It would have had to eat huge amounts of vegetation to sustain its great size. It ate leaves and needles of conifers and tree ferns and any other plant it could reach. Ultrasaurus fed almost constantly, probably always moving to search for food.

Ultrasaurus was preyed upon by the 2 ton carnivorous predator Allosaurus and its relatives such as Ceratosaurus, which were no match for these 80 ton giant sauropods. However, packs of Allosaurus could have followed the herds, attacking juveniles or waiting for a sick sauropod to fall. A healthy adult Ultrasaurus was rarely bothered by predators.

Fossils have been found in South Korea. Ultrasaurus is known from part of an upper forearm (humerus), and some back bones (vertebrae).

Ultrasaurus was named by Kim in 1983. The type species is U. tabriensis. Haang Mook Kim published a paper in 1983, describing a new dinosaur which he named Ultrasaurus tabriensis, because he believed it was an equally giant relative of Jensen's dinosaur. However, Kim's assessment was incorrect. His dinosaur was much smaller than he believed, because he mistook a leg bone (femur) for an arm bone (humerus). However, since Kim was the first to publish the name Ultrasaurus, the name officially applies to the South Korean dinosaur.