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. 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 sandy braided river, floodplain and ephemeral lake depositional environments, as opposed to the desert depositional environment of the Djadochta Formation.

Color key Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon		Notes Uncertain or tentative taxa are in small text; crossed out taxa are discredited.

Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Abdarainurus	A. barsboldi				A titanosaurian sauropod

Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Pinacosaurus	P. grangeri				A ankylosaurid thyreophoran
Plesiohadros	P. djadokhtaensis				A hadrosauroid ornithopod
Protoceratops	P. andrewsi				A protoceratopsid ceratopsian

Turtles of the Alagteeg Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Trionychidae Indet.	Indeterminate

• List of dinosaur-bearing rock formations

• Averianov, Alexander O.; Lopatin, Alexey V. (2020), "An unusual new sauropod dinosaur from the Late Cretaceous of Mongolia", Journal of Systematic Palaeontology, 18 (12): 1009–1032, Bibcode:2020JSPal..18.1009A, doi:10.1080/14772019.2020.1716402
• Hasegawa, Hitoshi; Tada, Ryuji; Ichinnorov, Niiden; Minjin, Chuluun (2009), "Lithostratigraphy and depositional environments of the Upper Cretaceous Djadokhta Formation, Ulan Nuur basin, southern Mongolia, and its paleoclimatic implication", Journal of Asian Earth Sciences, 35 (1): 13–26, Bibcode:2009JAESc..35...13H, doi:10.1016/j.jseaes.2008.11.010
• Weishampel, David B.; Dodson, Peter; Osmólska, Halszka (2004), The Dinosauria, 2nd edition, Berkeley: University of California Press, pp. 1–880, ISBN 0-520-24209-2, retrieved 2019-02-21