Aublysodon

Aublysodon is an extinct genus of dubious dinosaur theropod that belongs to the Tyrannosauridae family. 

Currently, scientists have recognized only one species in this genus: Aublysodon mirandus. The species was named in 1868 by Joseph Leidy. 

 Fossils 
Paleontologists found Aublysodon fossils in Montana, U.S.A. that are around 75 million years old. At that time, the world was in the Campanian stage of the Upper Cretaceous Period.

Several possible A. mirandus fossils have been found in Asia and Canada.Currie, P. (2005). "Theropods, including birds." Pp. 367-397 in Currie and Koppelhus (eds)., Dinosaur Provincial Park: A Spectacular Ancient Ecosystem Revealed. Bloomington: Indiana University Press.

 Other species 
Other species were named as possible Aublysodon. However, scientists found that they belong to other extinct species, like juvenile Tyrannosaurids such as Tyrannosaurus, Daspletosaurus and Gorgosaurus. 

 Taxonomy 

When Joseph Leidy named Aublysodon mirandus in 1868 by Joseph Leidy, the holotype consisted of a single tooth, named ANSP 9535. In the same year, fossils of Troodon, Trachodon and Deinodon were found in similar localities in the Western United States.

In Judith River Formation, between 1854-1855, archaeologists found a fossil of Deinodon horridus."Aublysodon." Dodson, et al. Page 128. The fossil was formally described in 1866 by Edward Drinker Cope. 

The name Aublysodon mirandus is a junior objective synonym of Deinodon horridus. Because of this, in 1868 Cope renamed the Deinodon horridus as a second species, Aublysodon horridus.Cope, E.D., 1868, "On some Cretaceous Reptilia", Proceedings of the Academy of Natural Sciences of Philadelphia, 20: 233-242 Today, the fossil of Aublysodon is referred as juvenile Tyrannosaurids, such as Daspletosaurus or Tyrannosaurus. New studies replaced Aublysodon as a nomen dubium.

 Referred species 
Apart from A. mirandus and A. horridus, several others species have been named within the genus. In 1876, Cope named the Aublysodon lateralis, based on specimen AMNH 3956,Cope, E.D., 1876, "Descriptions of some vertebrate remains from the Fort Union Beds of Montana", Paleontological Bulletin, 22: 1-14Cope, E.D., 1876, "Descriptions of some vertebrate remains from the Fort Union Beds of Montana", Proceedings of the Academy of Natural Sciences of Philadelphia, 28: 248-261 but now referred to a synonym of Deinodon horridus.Sahni, A. (1972). "The vertebrate fauna of the Judith River Formation, Montana." Bulletin of the AMNH, 147(6). 

In 1963, the paleontologist Alan Jack Charig named three species: Aublysodon lancinator, Aublysodon novojilovi and Aublysodon lacensis. Today they are classified as synonyms of Tarbosaurus and Tyrannosaurus or a separate genus called as Nanotyrannus.Bakker, R.T., Williams, M. & Currie, P.J., 1988, "Nanotyrannus, a new genus of pygmy tyrannosaur, from the latest Cretaceous of Montana", Hunteria 1(5): 1-30

 Size 
Estimates say that Aublysodon was about 4 meters (13 ft) tall. Its maximum size was around 7–8 meters (23–26 ft) long, with a maximum weight of 3 tons (3.1–3.6 short tons).

 References 

Category:Tyrannosaurids
Category:Cretaceous dinosaurs
Category:North America
Category:Animals of North America
Category:Theropods
Category:Dinosaurs of North America
Category:Dinosaurs of Asia