Acrocanthosaurus

**Name:** *Acrocanthosaurus*‭ (‬High spined lizard‭)‬.
**Phonetic:** Ak-row-can-fo-sore-us.
**Named By:** John Willis Stovall‭ & ‬Wann Langston,‭ ‬Jr.‭ ‬-‭ ‬1950.
**Classification:** Chordata,‭ ‬Reptilia,‭ ‬Dinosauria,‭ ‬Saurischia,‭ ‬Theropoda,‭ ‬Carcharodontosauridae.
**Species:** *A.‭ ‬atokensis*‭ (‬type‭)‬.
**Type:** Carnivore.‭

**Size:** Up to‭ ‬11.5‭ ‬meters long.
**Known locations:** USA,‭ ‬Oklahoma,‭ ‬Antlers Formation,‭ ‬and the Texas,‭ ‬Twin Mountains Formation.‭ ‬Some specimens from other parts of the US.
**Time period:** Aptian to Albian of the Cretaceous.

**Fossil representation:** Several specimens of partial remains.‭ ‬Combined study of all these specimens has allowed Acrocanthosaurus to be very well reconstructed.

*Acrocanthosaurus* immediately‭ ‬sticks out from other large theropods with its high dorsal spines than run from the neck to the tip of the tail.‭ ‬There have been many artistic representations for this structure from the spines standing proud from the body,‭ ‬to supporting a flap of skin.‭ ‬Modern thinking however comes from the examination of the lower spines that have attachments for muscles.‭ ‬This has led to the suggestion that the spines supported a hump of tissue that ran down the length of *Acrocanthosaurus*.
The purpose of the hump of *Acrocanthosaurus* has been subject to a lot of speculation.‭ ‬Some have said that it would provide a larger surface area than *Acrocanthosaurus* would have had without it,‭ ‬helping with temperature exchange and reducing negative effects of gigantothermy.‭ ‬It could have been composed of fatty tissue and used to keep *Acrocanthosaurus* going for extended periods without eating.‭ ‬It may have also been a form of visual display for other *Acrocanthosaurs* to gauge its level of health,‭ ‬perhaps even having a different colour or markings to the rest of its body.

It is possible that the hump served double duty.‭ ‬If composed of fatty tissue,‭ *‬Acrocanthosaurus* would have had to eat more than the minimum it would have had to just to survive.‭ ‬This would then result in a large and well maintained hump that would speak along the lines of‭ '‬Look at‭ ‬my hump.‭ ‬That is how much of a successful predator I am.‭ ‬That‭’‬s why I am more worthy of passing my genes down to the next generation‭'‬.‭ ‬It could have also worked in dominance displays between two *Acrocanthosaurus*,‭ ‬with the larger hump meaning that they were a more capable hunter‭ ‬and knew what to do when things came to a fight.‭ ‬The *Acrocanthosaurus* with the smaller hump would then probably back down instead of go up against what appeared to be a stronger and more capable *Acrocanthosaurus*.
*Acrocanthosaurus* was big for its time,‭ ‬a family trait that is shared with‭ ‬some other carcharodontosaurids such as *Carcharodontosaurus* and *Giganotosaurus*.‭ ‬At‭ ‬eleven and a half‭ ‬meters,‭ *‬Acrocanthosaurus* would have been the largest predator of its time and locale.‭ ‬Its diet as a result probably consisted of hadrosaurs and smaller sauropods,‭ ‬dinosaurs that were large enough to provide sufficient sustenance,‭ ‬while being too slow to escape.‭ ‬Study of the area that the main *Acrocanthosaurus* remains come from suggest that it was probably the apex predator of its location,‭ ‬with most other predators such as *Deinonychus* being much smaller.

The skull of *Acrocanthosaurus* featured large fenestra,‭ ‬a necessary adaptation to reduce the weight of its huge skull that could approach up to a‭ ‬one hundred and thirty‭ centi‬meters long.‭ ‬The teeth of *Acrocanthosaurus* were curved and serrated like other members of the carcharodontosaurid group.‭ ‬The maxilla and premaxilla contained‭ ‬a total of around thirty-eight teeth.‭ ‬The teeth in the lower jaw are generally smaller than those above and can approach up to thirty in number.‭ ‬Another carcharodontosaurid trait is the bony brow ridge above the eye,‭ ‬formed by the lacrimal and postorbital bones coming together.