Quaesitosaurus

*Quaesitosaurus orientalis*

***Quaesitosaurus*** (meaning "extraordinary lizard") is a genus of nemegtosaurid sauropod containing only the type species, ***Q. orientalis***, described by Kurzanov and Bannikov in 1983. It lived from 75 to 73 million years ago during the Late Cretaceous (Santonian to Maastrichtian ages). Its fossils, consisting solely of a partial skull designated as the holotype PIN 3906/2, were found in the Barun Goyot Formation near Shar Tsav, Mongolia. With long, low and horse-like with frontally located peg-teeth, the skull of *Quaesitosaurus* is similar enough to the skull of *Diplodocus* and its kin to have prompted informed speculation that the missing body was formed like those of diplodocids.

## Discovery

During the Combined Soviet-Mongolian Paleontological Expeditions in 1971, an isolated, incomplete sauropod skull and nearly complete mandible were unearthed at a fossil site in the Upper Cretaceous bluffs of the Barun Goyot Formation near Shar Tsav, Mongolia. The fossils were later transported to the Paleontological Institute of the Russian Academy of Sciences (then the USSR Academy of Sciences) where they were catalogued as PIN 3906/2. The specimen wasn't described until 1983, when S. M. Kurzanov and A. F. Bannikov named it Quaesitosaurus orientalis, the genus name meaning "abnormal lizard" after the abnormal skull anatomy and the species name meaning "eastern", referring to the fossil's origin in Mongolia. It is possible that Nemegtosaurus, also known from only skull material, is a very close relative of Quaesitosaurus.

## Description

It is possible that *Nemegtosaurus*, also known from only skull material, is a very close relative of *Quaesitosaurus*, if not in fact a variation of the same animal. However the remains are less complete than that of Nemegtosaurus . The snout of Q. orientalis appears to be broader than in Nemegtosaurus and the squamosal shorter and does not come into contact with the quadrate-jugal. The dorsal processes of the maxillae and premaxillae are missing, as are the jugals, lacrimals, prefrontals, and part of the frontal, so that no part of the edges of the nares or the antorbital window is preserved, and its forms remain hypothetical. The mandible is essentially complete. In 1994 Hunt and colleagues placed it among the dicreosaurids, but later and with the appearance of several specimens of titanosaur skulls, it was included in this group along with Nemegtosaurus .

## JPInstitute.com Description

Quaesitosaurus was a very large plant-eating, long-necked dinosaur from Asia. Since only part of the skull has been found, very little is known about exactly how big this animal was, or exactly what it looked like.

With such little fossil material with which to work, there has been a great deal of speculation about Quaesitosaurus. It has been variously classified under two different families - diplodocids and titanosaurs. Some scientists believe that its mouth design suggests that it ate mostly soft water plants and have even suggested the animal itself would have lived in the water a great deal of the time.

## Links

http://web.archive.org/web/20031006221956/http://www.jpinstitute.com/dinopedia/dinocards/dc\_quaes.html