Alagteeg Formation

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 sandy braided river, floodplain and ephemeral lake depositional environments, as opposed to the desert depositional environment of the Djadochta Formation.^[2]

Alagteeg Formation
Stratigraphic range: Santonian-Campanian ~85–72 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Type	Geological formation
Underlies	Djadochta Formation
Thickness	~16 m (52 ft) at the Bayan Zag locality
Lithology
Primary	Sandstone, mudstone
Location
Coordinates	44.3°N 103.3°E / 44.3; 103.3
Approximate paleocoordinates	41.9°N 92.4°E / 41.9; 92.4
Region	Ömnögovi Province
Country	Mongolia
Extent	Ulaan Nuur Basin
Type section
Named for	Alag Teeg
Named by	Hasegawa et al.
Year defined	2009
Thickness at type section	~15 m (49 ft)
Alagteeg Formation (Mongolia)

Fossil content

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.

Dinosaurs

Sauropoda

Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Abdarainurus[3]	A. barsboldi				A titanosaurian sauropod

Ornithischians

Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Pinacosaurus[1]	P. grangeri				A ankylosaurid thyreophoran
Plesiohadros	P. djadokhtaensis				A hadrosauroid ornithopod
Protoceratops[1]	P. andrewsi				A protoceratopsid ceratopsian

Turtles

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

See also

• List of dinosaur-bearing rock formations