Nemegtosauridae

Nemegtosauridae is a family of titanosaurian sauropod dinosaurs based on their diplodocid-like skulls. Only three species are known: Nemegtosaurus, Quaesitosaurus and possibly Tapuiasaurus, each from the Cretaceous.

==History of classification== thumb|left|Skull reconstruction of Tapuiasaurus Due to the diplodocid-like nature of the taxa placed in Nemegtosauridae, the systematic position of this family in Sauropoda was disputed until recently. McIntosh (1990) included both these animals in the family Diplodocidae, subfamily Dicraeosaurinae, as they resemble the skull of Dicraeosaurus, although differing in certain details. Although the skull of Nemegtosaurus was found in the same formation as the headless skeleton of Opisthocoelicaudia, McIntosh (1990) kept Nemegtosaurus in Diplodocoidea while keeping Opisthocoelicaudia separate from the former, a position reiterated by Upchurch (1995, 1999), and Upchurch et al. (2004). A cladistic analysis published in 2002 transferred Nemegtosaurus and Opisthocoelicaudia from Diplodocoidea to Titanosauria.