Aublysodon

From Wikipedia, the free encyclopedia

Aublysodon
Fossil range: Late Cretaceous

Extinct (fossil)

Scientific classification

Kingdom:	Animalia
Phylum:	Chordata
Class:	Sauropsida
Order:	Saurischia
Superfamily:	Tyrannosauroidea
Family:	Tyrannosauridae
Genus:	Aublysodon

Binomial name

Aublysodon mirandus
Leidy, 1868

Aublysodon (uncertain derivation; perhaps "backwards-flowing tooth"?) is a carnivorous dinosaur taxon named by Joseph Leidy in 1868. It is a dubious name, since the type specimen consists only of isolated fossil teeth, found in strata from the Late Cretaceous Period [1]. These teeth almost certainly belong to a tyrannosaurid, but cannot be identified with any more specificity.

In the mid and late 1800s (19th century) many dinosaur taxa were named for isolated teeth; such genera include Trachodon, Palaeoscincus, and Troodon. Even before the badlands of North America started revealing the bones of Tyrannosaurus, many paleontologists of that time agreed that long, pointed teeth turning up in many localities in the Western United States belonged to the deadliest, most ferocious dinosaurs that ever lived. The tendency then was to give each set of remains its own name and Leidy named one set of teeth Aublysodon in 1868. Since then, over a dozen species of this supposedly fearsome theropod have been described.

The first post-dentary remains of Aublysodon was a partial skull unearthed in Montana in the 1980s. The skull bore the same pointed teeth attached to a long narrow skull the length of an average human arm. This adaptation resembles that of theropods designed for eating fish. Famous dinosaurologist and paleoartist Gregory S. Paul decided the skull should belong to a new species, Aublysodon molnari. Unfortunately, with only this partial skull and isolated teeth, very few other details can be given about this elusive animal. We do know that Aublysodon was widespread; its remains have been found in many locations.

As with some other theropods, many paleontologists no longer use Aublysodon as a valid genus. It is now widely considered to be just a juvenile Tyrannosaurus, due to longer teeth and larger eyes characteristic of younger specimens of that species.

[edit] Species

Type:

Aublysodon mirandus Leidy, 1868 (including Ornithomimus mirandus and Deinodon horridus, in part); teeth only

Other Species:

A. amplus (Marsh, 1892) and
A. cristatus (Marsh, 1892) were at one stage included with A. mirandus, but have now been referred to the corresponding Stygivenator (=Tyrannosaurus rex) species.
A. explanatus (Cope, 1876/Hatcher, 1903); nomen dubium included with Paronychodon explanatus.
A. (= Deinodon) grandis (Marsh, 1890/von Huene, 1932); nomen dubium
A. (= Deinodon) horridus (Leidy, 1856/Cope, 1868); nomen dubium
A. (= Deinodon) lateralis (Cope, 1876); nomen dubium
A. huoyanshanensis (Dong, 1977/Paul, 1988); from Shanshanosaurus, now believed to be a juvenile Tarbosaurus bataar.
A. lancensis (Gilmore, 1946/Charig, 1967); included with Nanotyrannus lancensis.
A. lancinator (Maleev, 1955/Charig, 1967); = Tarbosaurus bataar.
The "Jordan theropod", from Montana, originally A. molnari (Paul, 1988), was made the type species for Stygivenator by Olshevsky in 1992, but appears to be a juvenile Tyrannosaurus rex.
A. novojilovi (Maleev, 1955/Charig, 1967) is considered to be a juvenile Tarbosaurus bataar.