Quaesitosaurus, which means “extraordinary lizard”, is a genus nemegtosaurid sauropod that only contains the type species Q. orientalis. Kurzanov, Bannikov, 1983, first described it. It lived between 75 and 73 million years ago in the Late Cretaceous (Santonian-Maastrichtian ages). The Barun Goyot Formation, near Shar Tsav in Mongolia, contained only a fragment of its skull, designated as the PIN 3906/2. The skull of Quaesitosaurus, which is long, low, and horse-like, has frontally placed peg-teeth. This suggests that it was similar to Diplodocus’ skull.

PaleoNeolitic, CC BY 4.0, via Wikimedia Commons

It is possible that Nemegtosaurus is very similar to Quaesitosaurus.

Source: Wikipedia