The Alagteeg Formation is a geological formation in Mongolia whose strata date back to the Late Cretaceous. Dinosaur remains are among the fossils that have been recovered from the formation.[1] It predominantly consists of alternating reddish brown mudstone and horizontally laminated sandstone, with ripple cross laminations and rhizoliths. It was first formally defined as a unit by Hasegawa et al. in 2008 as a distinct unit from the overlying Djadochta Formation. The environment of deposition is suggested to be fluvial, originating in a sandy braided river, floodplain and ephemeral lake depositional environments, as opposed to the desert depositional environment of the Djadochta Formation.[2]
