Fossil skull of Carcharodontosaurus
Carcharodontosaurus ( altgr. " Sharptooth lizard" or " shark tooth lizard" ) is a genus of theropod dinosaur from the Early Cretaceous of Africa.
It was one of the largest known terrestrial carnivores of the Earth's history. He is the eponymous representative of Carcharodontosauridae and was closely related to the genera also gigantic Giganotosaurus and Mapusaurus. The first finds of this dinosaur paleontologist Ernst Stromer made the German von Reichenbach in Algeria and Egypt. All of this material was destroyed during an allied air raid on Munich 1944.
Currently, two types are distinguished - the type species of Carcharodontosaurus saharicus and discovered in Niger in 2007 Carcharodontosaurus iguidensis.
- 2.1 brain
- 3.1 List of important discoveries
Lange was unclear which group Carcharodontosaurus is classified. Had Stromer assigned him to the taxon named after him Carcharodontosauridae, so this was regarded by other scientists as invalid and Carcharodontosaurus assigned to Allosauridae or Tyrannosauridae. In 1995, Oliver WM Rauhut published a detailed work on the currently accepted classification of Carcharodontosaurus and the related with it Bahariasaurus. This publication was based mainly on the records Stromers since the original fossils were destroyed during the Second World War.
Due to many similarities can be assumed that among the Carcharodontosauridae Allosauroidea; of other representatives of this group, the Allosauridae and Sinraptoridae, they split at ease from the Middle Jurassic. They are probably closer to the Allosauridae used as the Sinraptoridae. The Carcharodontosauridae were the most derived ( advanced ) Representatives of Allosauroidea.
Distinction saharicus C. and C. inguidensis
In Niger were fossils of a second type, C. inguidensis discovered. This finding shows that teeth and other material from the area of the discovery site, which has been asked to C. saharicus, in reality belonged to C. iguidensis. In the vicinity also fossils were found by Rugops primus and Spinosaurus and it is considered unlikely that more than three large theropods lived together in such a small space. So many fossils from the area have now been assigned to C. iguidensis.
C. iguidensis and C. saharicus differ inter alia in the construction of the lacrimal bone and the maxilla. Both types show grooved teeth, wherein the groove in C. saharicus are more pronounced than that of C. iguidensis. In addition, C. iguidensis has about 15% more brain volume than C. saharicus; However, both types had less brain mass than Tyrannosaurus.
Carcharodontosaurus was up to 13.7 meters long, had strong claws and serrated on both sides, usually hardly curved teeth.
However, in the different regions of Africa occurred on regional characteristics. Characteristic of Carcharodontosauriden next Pleurocoelen ( lateral openings ) in the caudal vertebrae, which is a rarity among theropods, especially the extremely wide and flat neck vertebrae.
Prefrontal brain and skull of Carcharodontosaurus show significant differences from those of the Allosauridae and Sinraptoridae and are similar to those of Giganotosaurus and Acrocanthosaurus. Also, an air filled extension of the middle ear is characteristic of Carcharodontosaurus, Acrocanthosaurus and Giganotosaurus possibly.
The anatomy of the inner ear of Carcharodontosaurus is comparable to today's crocodiles, the lower jaw similar in structure to the other Carcharodontosauridae and optic nerve and eye movement strong.
In 2000, a research team created by Hans Larsson Schädelausgüsse of Tyrannosaurus, Allosaurus and Carcharodontosaurus and compared here, among other things, the size ratio of the cerebrum compared to the entire brain. As with most dinosaurs, this ratio was comparable with that of today's reptiles at Carcharodontosaurus and Allosaurus, while the cerebrum occupied more space in Tyrannosaurus. This can be explained that Tyrannosaurus is much closer related to birds than the two Allosauroidea. Birds have a significantly larger cerebrum than reptiles in comparison to body size. In addition, it can be assumed that Tyrannosaurus with similar size and a higher overall volume of the brain had as Carcharodontosaurus.
Discovery and finds
The first belonging to Carcharodontosaurus fossils were two teeth found in Algeria who falsely Megalosaurus were first allocated and how all the material found at that time, were lost in the Second World War.
Later this dinosaur fossils have been found in Egypt, Morocco, Tunisia, Libya and Niger.
List of important discoveries
Among the fossils of Carcharodontosaurus include a skull fragment, the nasal bone, fragments of the left maxilla, three cervical vertebrae, several teeth, a tail vertebrae, a rib fragment, foot bones, fragments of the left ischium, both pubes (destroyed), both femurs ( destroyed ) and the left fibula. Stromer mentioned in his notes also a Hüftbeinknochen whose membership has not been clarified to Carcharodontosaurus.