Khuren Dukh Formation

The Khuren Dukh Formation, also known as the Khukhtyk Formation, Khukhteeg Formation, or Hühteeg Svita, (Mongolian: Хөхтээг формаци, Khökhteeg Formatsi), is a geological formation in Mongolia whose strata date back to the Aptian–Albian ages of the Early Cretaceous.^[2][3] Dinosaur remains are among the fossils that have been recovered from the formation.^[4]

Khuren Dukh Formation
Stratigraphic range: Early Cretaceous (Aptian–Albian),[1] 119.7–100 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Type	Geological formation
Sub-units	Lower, Middle & Upper Members
Underlies	Terrace deposit, Basalt
Overlies	Khalzan Uul Formation, Basement
Thickness	Over 100 m (330 ft)
Lithology
Primary	Sandstone, conglomerate, siltstone, mudstone
Location
Coordinates	45.9°N 108.4°E / 45.9; 108.4
Approximate paleocoordinates	49.3°N 100.2°E / 49.3; 100.2
Region	Dornogovi Province
Country	Mongolia
Extent	Choyr Basin
Khuren Dukh Formation (Mongolia)

Vertebrate paleofauna

Dinosaurs

The earliest record of Pachycephalosauria.^[5]

Dinosaurs of the Khuren Dukh Formation (Hühteeg Svita)
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Altirhinus	A. kurzanovi			"Complete skull, partial skull, associated postcrania, several individuals."[6]	A hadrosauroid ornithopod
Choyrodon[7]	C. barsboldi			Partial skull, cervical ribs	A hadrosauroid ornithopod
Iguanodon	I. orientalis				An indeterminate Iguanodont. A referred skull was reclassified as Altirhinus.
Harpymimus[8]	H. okladnikovi			Partial skeleton	An ornithomimosaur

Choristoderes

Choristoderes of the Khuren Dukh Formation (Hühteeg Svita)
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Khurendukhosaurus	K. orlovi, Indeterminate			Partial skeleton	Long-necked choristodere
Tchoiria	T. namsarai				Crocodile-like neochoristoderan.

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.

See also

• List of dinosaur-bearing rock formations