Acrocanthosaurus (meaning “high-spine lizard” because of the spikes growing out of its spine) was a fierce predator that was roughly 30-40 feet (9-12 m) long and weighed about 5,000 pounds (2300 kg). It had a big head, with a 4.5 foot (1.4 m) long skull and 68 thin, sharp, serrated teeth. It had 17-inch (43 cm) spikes extending from its vertebrae, along the neck and tail, that may have formed a thick, fleshy sail on its back. It had powerful arms, and each hand had three fingers, equipped with long, sickle-like claws.
When Acrocanthosaurus lived
Acrocanthosaurus lived during the early Cretaceous period, roughly 115-105 million years ago, in the tropics near sea level.
Acrocanthosaurus may have been a carnosaur, whose intelligence (as measured by its relative brain to body weight, or EQ) was high among the dinosaurs.
Acrocanthosaurus was a carnivore, a meat eater. It was a large, fierce predator that could kill even large sauropods. Acrocanthosaurus may also have been a scavenger.
Acrocanthosaurus walked on two long, muscular legs.
Discovery and naming of fossils
Acrocanthosaurus fossils have been found in what is now the USA, in Oklahoma, Texas, and Utah. Acrocanthosaurus is known from incomplete skeletons and teeth and was named by paleontologists Stovall and Langston in 1950. Acrocanthosaurus atokensis is the type species. Many Acrocanthosaurus tracks have also been found.
Acrocanthosaurus was a Saurischian (“lizard-hipped”) dinosaur. It was a theropod, and may have been a carnosaur and an allosaurid (huge carnivores with bony head ridges that may have hunted in packs; they included Allosaurus, Saurophaganax, and Neovenator).
Other Dinosaur Information Sheets
Names with an asterisk (*) were not dinosaurs.