Aristosuchus ("brave crocodile") is a genus of coelurosaurian compsognathid theropod dinosaur from the Early Cretaceous of England. It had little, sharp, needle-like teeth inside its jaws, for snapping up small animals such as frogs, insects, mammals, lizards, and early birds. Aristosuchus was about 6 feet long and weighed at least 50-100 pounds. It lived along with Iguanodon, Baryonyx, Valdosaurus, Hypsilophodon, Hylaeosaurus, Polacanthus, and Eotyrannus. Its close relatives are Compsognathus, Juravenator, and Sinosauropteryx. It was swift, may have been covered in downy feathers like Sinosauropteryx, and prpbably cared for its young, like a bird.
Discovery[]
Holotype elements as figured by Owen
The type species, Aristosuchus pusillus, was described in 1876 by Richard Owen and named Poekilopleuron pusillus. The specific epithet means "small" in Latin. Harry Govier Seeley (1839–1909) gave it the name Aristosuchus in 1887.
It was found in the Wealden Group dating to the Early Cretaceous (Barremian) in England, on the Isle of Wight, i.e. from about 125 million years ago.
Description[]
Aristosuchus was a bipedal, meat-eating (carnivorous) theropod dinosaur. This predator is thought to have been about 2 metres (6.6 ft) and is estimated to have weighed about 30 kilograms (66 lb). According to Gregory S. Paul, its weight was 7 kilograms (15 lb).
The femur of Aristosuchus has a wing-like anterior trochanter and a markedly reduced fourth trochanter.
Classification[]
Hypothetical restoration as a compsognathid
Aristosuchus was originally named as a new species of Poekilopleuron, P. pusillus, from the Wessex Formation of the Isle of Wight. Woodward and Sherborn (1890) regarded Aristosuchus pusillus as being based on the same specimen that Reverend William D. Fox named Calamospondylus oweni in 1866, and many authors followed suit (some regarding C. oweni as a nomen nudum). However, Naish (1999, 2002) showed that Calamospondylus was based on a different specimen than the Aristosuchus holotype based on letters of correspondence between Richard Owen and Reverend Fox as well as discrepancies in the original description.
Naish (1999, 2002) placed Aristosuchus in Compsognathidae. Aristosuchus is known from holotype NHMUK R.178: a sacrum, a pubis, a femur and a few vertebrae. Two ungual phalanges were found nearby, which may have been from the same animal and would suggest long claws.
Dinosaur Earth Description[]
Aristosuchus was a small meat-eating dinosaur that lived in Europe. It is still being discussed if this is the same as Calamospondylus although the most recent research says that it is a separate dinosaur. Both of these dinosaurs were discovered in the early days of paleontology, in the latter part of the 19th century. Since Calamospondylus was discovered in 1866, and Aristosuchus in 1887, the name of the earlier discovery would be the one accepted by scientists if both dinosaurs prove to be the same creature.
A recent analysis of the remains, along with papers by the original discoverers that came to light in 2000, may have settled the debate and given Aristosuchus legitimacy as a genus. At present, it is considered a valid name and placed in the same family as Compsognathus.
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