Carcharodontosaurus

Carcharodontosaurus is a genus of large theropod dinosaurs native to northern Africa during the late Cretaceous period, approximately 100-93 million years ago. Carcharodontosaurus is among the largest known theropods, being comparable in size to Tyrannosaurus, Giganotosaurus and Mapusaurus, but smaller than Spinosaurus.

The name Carcharodontosaurus means "jagged-toothed reptile" (from the Greek καρχαρο karcharo meaning "jagged", οδοντο odonto σαυρος, sauros meaning reptile.

Discovery and fossil record
Carcharodontosaurus fossils were first found by Charles Depéret and J. Savornin in the Continental intercalaire of Algeria (dating to the Albian stage) in 1927. Originally called Megalosaurus saharicus (many theropods were once erroneously referred to as Megalosaurus), its name was changed in 1931 by Ernst Stromer von Reichenbach to that used today. Stromer named Carcharodontosaurus "for its mainly Carcharodon-like teeth", which were "not recurved, almost bilaterally symmetrical but with convex edges."

Specimens
Carcharodontosaurus is known from relatively few specimens. The holotype specimen, discovered by Ernst Stromer in 1931, consisted of several teeth and part of a lower jawbone. Sadly, this specimen was destroyed during World War II along with the holotype specimen of Spinosaurus. All that remains of this specimen are a few illustrations.

The second specimen was discovered in the 1980s. This specimen was more complete, with a number of teeth and part of the rear skull. Based on Allosaurus, this specimen was completed artificially and is on display in Santa Barbara.

Further Carcharodontosaurus saharicus specimens have been found. These consist mostly of teeth, with a few fragments from the skull, toes, and ribs. However, C. saharicus remains quite a mysterious dinosaur, as nothing even close to a complete skeleton has been discovered.

In 2006, material from a very large Carcharodontosaurus skull was discovered. Due to minor, but noticeable, differences between the new material and the C. saharicus skull, it was described as a new species, C. iguidensis. Current estimates place C. iguidensis at around 10 metres in length; noticeably smaller than C. saharicus. Not all paleontologists accept C. iguidensis as a scientifically valid species. Other views are that C. iguidensis was simply a large specimen of C. saharicus, or even a chimera.

Description and Paleoecology
Carcharodontosaurus was a very large theropod; yet sorting out its exact size is an issue, due to the fact that the proportionate size of the skull relative to the rest of the body is unknown. Carcharodontosaurus remains are fragmentary, and much of what is known about it is based on its close relative, Giganotosaurus. The total size of C. saharicus may have been anywhere between 11 and 14 metres long; weight estimates range from 6.3 to 15.1 metric tons; however, the upper weight estimates have been criticized by a number of authors.

Two species of Carcharodontosaurus have been named. The type species is Carcharodontosaurus saharicus, and the other is known as ''Carcharodontosaurus iguidensis. ''Both species appear to be adapted for hunting large prey, such as ornithopods and sauropods. Carcharodontosaurus species coexisted with sauropods as large as Paralititan stromeri, as well as smaller species including Aegyptosaurus baharijensis. Remains of related animals (Mapusaurus roseae found in groups or congregations may suggest a gregarious or pack-hunting way of life; a behaviour that may have extended to Carcharodontosaurus itself.

Carcharodontosaurus' temporal and geographical range also overlapped with that of the closely related Sauroniops as well as the massive, semiaquatic Spinosaurus aegyptiacus and the abelisaurid Rugops primus. Each of these predators likely exploited a different niche, allowing them to coexist while keeping competition to a minimum.

In popular culture
Carcharodontosaurus was featured in an episode of the television series Dinosaur Planet, titled "Alpha's Egg". The program erroneously depicted Carcharodontosaurus living in South America and preying on the sauropod Saltasaurus. In reality, Carcharodontosaurus remains have only been found in northern Africa. Carcharodontosaurus also appears in Jurassic Park: Operation Genesis as a four-star large carnivore. Yet another appearance is made in the first episode of Planet Dinosaur where it is despicted to fight for land and loses to Spinosaurus over a fight for an Ouranosaurus corps. It reappears in New Giants where it fights a Sarcosuchus over a juvenile Paralititan.