Acrocanthosaurus atokensis Dinosaur Facts

Acrocanthosaurus atokensis is an enormous theropod related to Carcharodontosaurus that lived several million years before during the Lower Cretaceous period in parts of North America. This dinosaur is poorly known by the general public but is one of the largest carnivores of the entire Mesozoic era. With a weight of about 5 tons and a length of more than 30 feet, the stature of Acrocanthosaurus was only surpassed by that of the gigantic Spinosaurus, Giganotosaurus and Tyrannosaurus Rex.

Acrocanthosaurus is easily distinguishable from its close relative Carcharodontosaurus since the vertebrae of its neck, back and tail are decorated with foot-long dorsal spines which almost certainly supported some kind of sail. In addition, computer tomography of the brain of this dinosaur showed that Acrocanthosaurus kept its head down with its snout pointing 25 degrees downward rather than straight ahead.

Origin of Acrocanthosaurus atokensis

The ancestral origins of Acrocanthosaurus atokensis remained for a long time quite mysterious. Resembling a larger and sturdier version of Allosaurus, it has been thought for a long time that it must be the closest relative of this Jurassic predator. It is only since remnants of similar creatures emerged from Africa and South America that Acrocanthosaurus was correctly classified as a carcharodontosaurid. Other animals in the same genus include Carcharodontosaurus, Giganotosaurus and Eocarcharia from Niger. Acrocanthosaurus and Allosaurus are both considered allosaurids but belong to different lineages and share only a distant common ancestor.

The evolutionary precursor of Acrocanthosaurus is Neovenator, one of the earliest carcharodontosaurid present in Europe, which subsequently spread by land to the continents of Africa, Asia and North America. The environmental conditions being different on each continent, several evolutionary lines would have developed and would have given birth to new species of carcharodontosaurids like Acrocanthosaurus.

Footprints at Dinosaur Valley State Park

In the Glen Rose formation in Texas, footprints dating back to the lower Cretaceous and left by a huge theropod abound and are likely to belong to Acrocanthosaurus since it is the only known carnivore of this time and region. According to some researchers, these tracks would record the story of a pack of Acrocanthosaurus chasing a herd of sauropods. However, there is no convincing evidence that this dinosaur hunted in groups.

Acrocanthosaurus atokensis fossil and exhibition

The most complete and well preserved skeleton of an Acrocanthosaurus atokensis was excavated on a private land in McCurtain County, Oklahoma, by amateur fossil collectors and hunters Sid Love and Cephis Hall. It took nearly 3 full years to unearth the bones and these were subsequently acquired by a US geology firm.

The 40-foot-long specimen is exhibited at the Natural Science Museum of North Carolina. The reconstruction is made from an intact skull and more than half of true fossil bones.