Djadochta Formation

Djadochta Formation
Stratigraphic range: Campanian, ~75–71  Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Bayn Dzak (Flaming Cliffs), the type locality of the Djadochta Formation
Type	Geological formation
Unit of	Shamo Group
Sub-units	Bayn Dzak Member, Tugrugyin Member
Underlies	Barun Goyot Formation
Overlies	Alagteeg Formation
Area	Nemegt Basin, Ulan Nur Basin
Thickness	over 90 m (300 ft)
Lithology
Primary	Sandstone
Other	Mudstone
Type section
Named for	Shabarakh Usu (Bayn Dzak)
Named by	Berkey & Morris
Location	Flaming Cliffs
Year defined	1927
Coordinates	44°08′19″N103°43′40″E / 44.13861°N 103.72778°E / 44.13861; 103.72778
Approximate paleocoordinates	30°42′N9°12′E / 30.7°N 9.2°E / 30.7; 9.2
Region	Ömnögov
Country	Mongolia
Thickness at type section	about 90 m (300 ft)

The Djadochta Formation (sometimes transcribed and also known as Djadokhta, Djadokata, or Dzhadokhtskaya) is a highly fossiliferous geological formation situated in Central Asia, Gobi Desert, dating from the Late Cretaceous period, about 75 million to 71 million years ago. The type locality is the Bayn Dzak locality, famously known as the Flaming Cliffs. Reptile (including dinosaur) and mammal remains are among the fossils recovered from the formation.

Excavation history

Cretaceous-aged dinosaur fossil localities of Mongolia. Djadochta localities at area B.

The Djadochta Formation was first documented and explored—though only a single locality—during paleontological expeditions of the American Museum of Natural History in 1922–1925, which were part of the Central Asiatic Expeditions. The expeditions were led by Roy Chapman Andrews, in company of Walter Willis Granger as chief paleontologist and field team. The team did extensive exploration at the Bayn Dzak (formerly Shabarakh Usu) region, which they nicknamed Flaming Cliffs given that at sunset the sediments of this locality had a characteristic reddish color. Notable finds included the first known fossils of Oviraptor , Protoceratops , Saurornithoides , and Velociraptor , the first confirmed dinosaur eggs (a partial nest of Oviraptor), as well as fossil mammals. Some of these were briefly described by Henry Fairfield Osborn during the ongoing years of the expeditions. In 1927 the formation was formally described and established by Berkey and Morris, with Bayn Dzak as the type locality. ^{[1] [2]}

In 1963, the Mongolian paleontologist Demberelyin Dashzeveg reported the discovery of a new fossiliferous locality of the Djadochta Formation: Tugriken Shireh. ^[3] During the 1960s to 1970s, Polish-Mongolian and Russian-Mongolian paleontological expeditions collected new, partial to complete specimens of Protoceratops and Velociraptor at this locality, making these dinosaur species a common occurrence in Tugriken Shireh. ^[4] Some of the most notable excavations made at Tugriken Shireh include the Fighting Dinosaurs (Protoceratops and Velociraptor locked in combat), ^{[5] [6]} and abundant articulated, in situ (in the original pose), and sometimes complete skeletons of Protoceratops. ^{[7] [8]}

During the 1980s, a joint Soviet-Mongolian paleontological expedition discovered several Mesozoic fossil-rich localities in the Gobi Desert of Mongolia. Among these sites, Udyn Sayr was discovered and examined by the expedition, regarding its age as Late Cretaceous. This new locality was predominantly rich in avimimid fossils, with a lesser abundance of mammal and other dinosaur fossils. ^[4]

In 1993 teams of a collaborative Mongolian-North American expedition (supported by the Mongolian Academy of Sciences and American Museum of Natural History) discovered a new fossil locality of the Djadochta Formation called Ukhaa Tolgod (meaning "Brown Hills"). Like previous localities, Ukhaa Tolgod has yielded a prominent abundance of well-preserved fossils, including high concentrations of mammal, dinosaur, lizard, and egg remains. A vast majority of specimens from this locality are usually found in near-complete articulation. Overall, when compared to other Mesozoic fossil sites, the diversity of fossils in Ukhaa Tolgod is unusually high. ^{[9] [10]}

Description

The modern-day Djadochta Formation is set in an arid habitat of sand dunes with little freshwater apart from oases and arroyos, in the Gobi Desert. The dominant lithology of the Djadochta Formation is represented by non-marine, cemented reddish-orange and pale orange to light gray, medium to fine-grained sands and sandstones, which include minor deposits of calcareous concretions and orange-brown silty clay. Less abundant sedimentation comprises conglomerates, siltstones, fluvial (water-deposited) sandstones, and mudstones. The entire thickness of the formation in the Ulan Nur Basin is at least 80 m (260 ft). Several aeolian processes (wind works) indicate the presence of large straight-crested dune-like structures, and smaller barchan (crescent-shaped) and parabolic (poorly U-shaped) dunes across the formation. ^{[11] [12] [10]} Reddish sandstones are observed in numerous localities. ^{[12] [10]}

Exposures at the Flaming Cliffs

• Bayn Dzak (also spelled Bain Dzak, Bayanzag, Bayn Zag, Bayan Zag, or Shabarakh Usu; locally known as Flaming Cliffs): It is dominated by reddish-orange sandstones and well-sorted, unbedded, and medium-grained sands. The thickness of the strata at the Flaming Cliffs at least more than 30 m (98 ft). Less abundant lithology of Bayn Dzak includes cemented and poorly-cemented siltstones, mudstones, and grayish conglomerates. The latter are better exposed at western escarpments of the Flaming Cliffs. ^{[13] [12]} Bayn Dzak is about 90 m (300 ft) in total thickness and can be divided into two sections: alternations of horizontally-bedded sandstone and mudstone in the lowermost part, and sandstone-dominated successions in the upper or main part. ^[14]
• Tugriken Shireh (also spelled Tugrik, Toogreeg, Toogreek, Tugreek, Tugrug, Turgrugyin, Tugrugeen, Tögrögiin, Tugrikiin, or Tugrikin): This locality is about 30 m (98 ft) in thickness and characterized by poorly cemented, fine-grained sandstones that have colors varying from pink to yellowish-white. The predominant mineral is quartz, and lesser common minerals are represented by feldspars and lithic fragments. Both cross-stratified and structureless sandstones are scattered across Tugriken Shireh. ^{[15] [12]}
• Udyn Sayr (also spelled Udan Sayr, Udan Sair, Ulaan Sair, or Üüden Sair): Sediments of this locality are exposed across a region of more than 60 km² (23 sq mi). It is divided into lower (thickness of at least more than 10 m (33 ft)) and upper (thickness of about 50 m (160 ft)) beds. The lower beds are fluvial originated and dominated by sandstones and mudstones. The upper beds are likely of aeolian origin and consist of reddish, cross-stratified and structureless sandstones. ^[16]
• Ukhaa Tolgod (also spelled Oka Tolga): The strata exposed at Ukhaa Tolgod is dominated by reddish sandstones, with some sandstones containing small amounts of conglomeratic lenses and/or cobbles and pebbles. Conglomerate itself is in this site, and to a lesser level are mudstones and siltstones, which are thin and laterally restricted. Cross-stratified and fine-structured sandstones are particularly abundant at Ukhaa Tolgod. ^{[17] [10]}
• Zamyn Khondt (also spelled Dzamyn Khondt, Zamin Khond, or Dzamin Khond): This locality is characterized by reddish, well-sorted, and fine-grained sandstones with calcareous concretions. Some aeolian beds are present and are finely stratified to massive, having a visible thickness of about 20 m (66 ft). ^[16]

Stratigraphy and age

The Djadochta Formation occurs in the Late Cretaceous period of the Campanian stage. Magnetostratigraphic datings from the Bayn Dzak and Tugriken Shireh localities suggest that the Djadochta Formation was deposited during a time of rapidly changing polarity at about 75 million to 71 million years ago. ^[12]

The Djadochta Formation is separated into a lower Bayn Dzak Member and an upper Turgrugyin Member, which represent very similar depositional environments. ^[12] Further strata from the Bayn Dzak Member includes that of the Ukhaa Tolgod locality, and its overall age is regarded also within the Campanian. ^[10]

Based on the superposition of the members, the Tugrugyin Member overlies the Bayn Dzak Member making it somewhat younger, which indicates that the Bayn Dzak paleofauna lived somewhat earlier than that from Tugriken Shireh. However, it is not yet understood the precise temporal difference: ^[12] Localities within the Djadochta Formation are considered to represent a sequence of progressively younger sediments and thereby paleofaunas. Ukhaa Tolgod may be younger than both Bayn Dzak and Tugriken Shireh. ^[18] Based on their fossil record and strata, Udyn Sayr and Zamyn Khondt have been correlated with other Djadokhta localities, though fossils of Udyn Sayr may indicate that this locality is younger than Bayn Dzak and Tugriken Shireh. ^[19]

Examinations on the strata of the Alag Teg (also spelled Alag Teeg or Alag Teer) locality, once considered part of this formation, indicates that it belongs to a different geological formation: the Alagteeg Formation, which is slightly older than the overlying Djadochta Formation. Based on sediments and stratigraphic relationships, the lower part of the Bayn Dzak locality is correlated with the Alag Teg locality, making both sections part of the Alagteeg Formation. The upper or main part of the former locality is considered part of the Djadochta Formation itself, as it shares similar lithology and stratigraphic relationships with Tugriken Shireh. ^[14]

Stratigraphy of the Djadochta Formation ^{[12] [14]}

Formation	Time period	Member	Lithology	Thickness	Image
Barun Goyot	Early Maastrichtian		Poorly cemented, fine and medium-grained red to reddish-brown sandstones.	~110 m (360 ft)
Djadochta	Campanian
		Turgrugyin	Pale orange to light gray (sometimes yellowish-white) sands and sandstones.	30 m (98 ft)
		Bayn Dzak	Reddish-orange, crossbedded, and structureless sandstones, with minor deposits of brown siltstones and mudstones.	90 m (300 ft)
Alagteeg	Early Campanian Santonian	"lower Bayn Dzak"	Alternating reddish brown mudstone and horizontally laminated sandstone, with ripple cross laminations and rhizoliths.	~15 m (49 ft)

Depositional environment

Based on strata and rock facies (such as sandstones and caliche) of the formation and coeval units (Bayan Mandahu) it is currently agreed that sediments of the Djadochta Formation were deposited by wind activity in arid paleoenvironments comprising sand dunes with a warm semi-arid climate. ^{[20] [12] [14]} Fluvial sedimentation at the Ukhaa Tolgod locality indicates the presence of short-lived water bodies during the times of the formation, which also contributed to its deposition. ^[10]

Taphonomy

Examples of the Djadochta Formation preservation: articulated Citipati (top) and Protoceratops (bottom) specimens

A vast majority of articulated specimens from the Djadochta Formation are found in unstructured sandstones, indicating burial in situ by high-energy sand-bearing events. Some buried Protoceratops individuals are preserved in distinctive postures involving the body and head arched upwards, suggesting that the animals died in the process of trying to free themselves from the body of sand, where they eventually fossilized. As they were unable to escape burial, the sandy mass prevented carcasses from being scavenged by vertebrates. Most of these "buried" specimens are found with bite traces and large borings (tunnel-like holes made by small invertebrates) on bone joints areas and other surfaces, indicating that after death they were largely scavenged by invertebrates, such as skin beetles. ^{[21] [22] [23]}

It has been suggested that the repeated occurrence of these feeding traces at limb joints may reflect that the responsible scavengers focused on collagen at the joint cartilage of dried dinosaur carcasses as a source of nitrogen, which was very low in the arid Djadochta Formation environments. ^[24]

Examinations at the fossil preservation and sediments of Ukhaa Tolgod indicates that preserved animals were buried alive by catastrophic dune collapses. It is thought to have occurred when sand dunes became oversaturated with water resulting in their sudden downfall; heavy rainfall events likely acted as the triggering mechanism for this collapse. ^{[9] [25] [10]} Examples from the Ukhaa Tolgod preservation include Citipati (brooding adults entombed atop nests and eggs); ^{[26] [27]} Khaan (a pair in close proximity likely killed by a single collapse event); ^[28] and Saichangurvel (individual buried alive by a muddy dune). ^[29]

Paleobiota of the Djadochta Formation

Articulated Protoceratops from Tugriken Shireh. This dinosaur is one of the most common occurrences in the Djadochta Formation

Among fossils, Protoceratops is extremely common in Djadochta localities. Bayn Dzak is reported as one of the localities with the highest concentration of Protoceratops fossils and has been noted as the "Protoceratops fauna". ^[30] Adjacent to Bayn Dzak, at Tugriken Shireh, Protoceratops is also abundant. ^[15] Other common dinosaur components of the paleofauna include Pinacosaurus and Velociraptor . ^[11] Small vertebrates like lizards and mammals are rather abundant and diverse, with Adamisaurus and Kryptobaatar being the most abundant representatives. ^{[29] [31] [30]} The paleofauna of the Djadochta Formation is very similar in composition to the nearby and coeval-regarded Bayan Mandahu Formation of Inner Mongolia. The two formations share many of the same genera, but differ in species. For instance, the most common mammal in Djadochta is Kryptobaatar dashzevegi, while in Bayan Mandahu it is the closely related K. mandahuensis. Similarly, the dinosaur fauna of Djadochta includes Protoceratops andrewsi and Velociraptor mongoliensis, which Bayan Mandahu yields P. hellenikorhinus and V. osmolskae. ^{[20] [32]}

Although fossil plants are extremely rare in the Djadochta Formation, the great abundancy of herbivorous Protoceratops at the arid-deposited Tugriken Shireh locality indicates that it had a moderate coverage of bushes or other low-growing plants. ^[15]

The relatively low paleobiodiversity and climate settings of the Djadochta suggest that these conditions contributed to stressed paleoenvironments. Most of the fossil occurrences in the formation are occupied by Protoceratops, and small to medium-sized ankylosaurs, oviraptorids, and dromaeosaurids make much of the overall paleofauna. Large-bodied animals are absent or extremely rare in the formation. Comparisons with the Nemegt Formation further reflects stressed paleoenvironments. In contrast to Djadochta, Nemegt has yielded an extensive diversity of large dinosaur taxa, such as Deinocheirus , Nemegtosaurus , Saurolophus , Tarbosaurus , or Therizinosaurus . Most of these taxa are herbivorous, which combined with the mesic (well-watered) settings of the Nemegt Formation allowed the development of giant herbivores, in contrast to the stressed Djadochta Formation. Another indicative of stressed paleoenvironments is the almost non-existent amount of fully aquatic animals. Turtles are rarely recovered, and most are terrestrial such as Zangerlia . ^[30]

Tyrannosaurids found in the formation may belong to an indeterminate species of Tarbosaurus , possibly extending the time range of the genus. ^[33] It is suggested that most of the fragmented hadrosaur, tyrannosaur and sauropod remains across the formation likely belong to non-endemic, passing by species. ^[30]

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.

Flora

Genus	Species	Location	Material	Notes	Images
Radicites	R. gobiensis	Bayn Dzak	"Twenty plant roots." [34]	A tracheophyte, likely conifer.

Amphibians

Genus	Species	Location	Material	Notes	Images
Gobiates	Indeterminate	Udyn Sayr	"Partial skeleton with partial urostyle." [35]	A frog.

Crocodylomorphs

Genus	Species	Location	Material	Notes	Images
Artzosuchus	A. brachicephalus	Udyn Sayr	"Partial skull." [36]	A crocodylomorph.
Gobiosuchus	G. kielanae	Bayn Dzak	"Multiple specimens with partial skulls and skeletons." [37] [38]	A gobisuchid.
	G.? parvus	Udyn Sayr	"Partial skull and skeleton." [39] [40]	A gobisuchid.
Shamosuchus	S. djadochtaensis	Bayn Dzak, Ukhaa Tolgod	"Two skulls and partial skeleton." [41] [42]	A paralligatorid.

Lizards

Genus	Species	Location	Material	Notes	Images
Adamisaurus	A. magnidentatus	Bayn Dzak, Tugriken Shireh, Ukhaa Tolgod	"Skulls and skeletons from multiple specimens." [43] [29]	A teiid. Also present in the Barun Goyot Formation and Bayan Mandahu Formation.
Aiolosaurus	A. oriens	Ukhaa Tolgod	"Incomplete skull and partial skeleton." [29]	A varanoid.
Carusia	C. intermedia	Bayn Dzak, Ukhaa Tolgod	"Skulls from multiple specimens." [29]	A carusiid. Also present in the Barun Goyot Formation and Bayan Mandahu Formation.
Cherminotus	C. longifrons	Tugriken Shireh, Ukhaa Tolgod	"Skulls and partial skeleton." [29]	A varanoid. Also present in the Barun Goyot Formation.
Ctenomastax	C. parva	Zos	"Incomplete skull." [29]	An iguanid. Also present in the Barun Goyot Formation.
Dzhadochtosaurus	D. giganteus	Tugriken Shireh	"Partially complete skull." [44]	A macrocephalosaur.
Eoxanta	E. lacertifrons	Ukhaa Tolgod	"Incomplete skull." [29]	A scincomorph. Also present in the Barun Goyot Formation.
Estesia	E. mongoliensis	Bayn Dzak, Ukhaa Tolgod	"Partial skulls and teeth." [29]	A monstersaur. Also present in the Barun Goyot Formation.
Flaviagama	F. dzerzhinskii	Tugriken Shireh	"Skull and two vertebrae." [45]	A priscagamid.
Globaura	G. venusta	Bayn Dzak, Ukhaa Tolgod	"Partial skulls." [29]	A scincomorph. Also present in the Barun Goyot Formation.
Gobiderma	G. pulchrum	Udyn Sayr, Ukhaa Tolgod	"Skulls and skin impressions." [29]	A monstersaur. Also present in the Barun Goyot Formation.
Gobinatus	G. arenosus	Ukhaa Tolgod	"Partial skull." [29]	A teiid. Also present in the Barun Goyot Formation.
Hymenosaurus	H. clarki	Ukhaa Tolgod	"Partial skull." [29]	A scincomorph.
Isodontosaurus	I. gracilis	Bayn Dzak, Tugriken Shireh, Ukhaa Tolgod, Zos	"Numerous skulls and a partial skeleton." [29]	An iguanian. Also present in the Bayan Mandahu Formation.
Macrocephalosaurus	Indeterminate	Ukhaa Tolgod	"Partial skull and skeleton." [29]	A teiid. Also present in the Barun Goyot Formation.
Mimeosaurus	M. crassus	Bayn Dzak, Ukhaa Tolgod, Zos Wash	"Partially complete skulls." [29]	An acrodont. Also present in the Bayan Mandahu Formation.
Myrmecodaptria	M. microphagosa	Ukhaa Tolgod	"Single skull." [29]	A gekkotan.
Ovoo	O. gurval	Little Ukhaa Tolgod	"Partial skull." [46]	A varanid.
Parmeosaurus	P. scutatus	Ukhaa Tolgod	"Articulated skull and skeleton." [29]	A scincomorph.
Phrynosomimus	P. asper	Ukhaa Tolgod	"Two partial skulls." [29]	An acrodont. Also present in the Barun Goyot Formation.
Priscagama	P. gobiensis	Bayn Dzak, Ukhaa Tolgod	"Incomplete skulls." [29]	An priscagamid. Also present in the Barun Goyot Formation.
Saichangurvel	S. davidsoni	Ukhaa Tolgod	"Complete skull and skeleton in articulation." [47]	An iguanian.
Slavoia	S. darevskii	Ukhaa Tolgod	"Skulls and skeleton." [29]	A scincomorph. Also present in the Barun Goyot Formation.
Telmasaurus	T. grangeri	Bayn Dzak	"Partial skull and skeleton." [48] [29]	A varanid.
Temujinia	T. ellisoni	Tugriken Shireh, Ukhaa Tolgod	"Several partial skulls." [29]	An iguanid.
Tchingisaurus	T. multivagus	Ukhaa Tolgod	"Partial skull." [29]	A teiid.
Unnamed scincomorph	Indeterminate	Ukhaa Tolgod	"Partial skull." [29]	A scincomorph.
Varanoidea indet.	Indeterminate	Ukhaa Tolgod	"Partial maxilla and vertebra." [29]	A varanoid.
Zapsosaurus	Z. sceliphros	Tugriken Shireh	"Two partial skulls." [29]	An iguanid.

Mammals

Genus	Species	Location	Material	Notes	Images
Asiatherium	A. reshetovi	Udyn Sayr	"Articulated skull and skeleton." [49]	A metatherian.
Bulganbaatar	B. nemegtbaataroides	Bayn Dzak, Ukhaa Tolgod	"Partial skull, and other remains." [50] [9]	A multituberculate.
Catopsbaatar	C. catopsaloides	Ukhaa Tolgod	Not specified. [9]	A djadochtatheriid. Also present in the Barun Goyot Formation.
Chulsanbaatar	C. vulgaris	Ukhaa Tolgod	"Skull and partial skeleton." [9]	A multituberculate. Also present in the Barun Goyot Formation.
Deltatheridium	D. pretrituberculare	Bayn Dzak, Ukhaa Tolgod	"Partial skull and skeleton remains." [51] [52]	A tribosphenid.
Deltatheroides	D. cretacicus	Bayn Dzak	"Partial skull." [51]	A djadochtatheriid.
Djadochtatherium	D. matthewi	Bayn Dzak, Tugriken Shireh	"Partial skulls." [53] [54]	A djadochtatheriid.
Hyotheridium	H. dobsoni	Bayn Dzak	"Partial skull." [51]	A therian.
	Indeterminate	Ukhaa Tolgod	Not specified. [9]	A therian.
Kamptobaatar	K. kuczynskii	Bayn Dzak, Ukhaa Tolgod	"Partial skull, and other remains." [55] [9]	A multituberculate.
Kennalestes	K. gobiensis	Bayn Dzak, Ukhaa Tolgod	"Nearly complete skull, and other remains." [56] [9]	An eutherian.
Kryptobaatar	K. dashzevegi	Bayn Dzak, Tugriken Shireh, Ukhaa Tolgod	"Skulls and skeleton remains from several specimens." [55] [31]	A djadochtatheriid. Gobibaatar and Tugrigbaatar are considered synonyms of this taxon. [57]
Maelestes	M. gobiensis	Ukhaa Tolgod	"Partial skull with skeleton." [58]	A cimolestid.
Mangasbaatar	M. udanii	Udyn Sayr	"Skulls and partial skeleton from two specimens." [59]	A djadochtatheriid.
Nemegtbaatar	N. gobiensis	Ukhaa Tolgod	Not specified. [9]	A multituberculate. Also present in the Barun Goyot Formation.
Sloanbaatar	S. mirabilis	Bayn Dzak, Ukhaa Tolgod	"Complete skull, and other remains." [55] [9]	A multituberculate.
Tombaatar	T. sabuli	Ukhaa Tolgod	"Partial skull." [60]	A djadochtatheriid.
Ukhaatherium	U. nessovi	Ukhaa Tolgod	"Partial to nearly complete skeletons from several specimens." [61] [62] [63]	An eutherian.
Zalambdalestes	Z. lechei	Bayn Dzak, Tugriken Shireh	"Skulls and skeletons from several specimens." [51] [64]	An eutherian.

Pterosaurs

Genus	Species	Location	Material	Notes	Images
Azhdarchidae indet.	Indeterminate	Tugriken Shireh	"Indeterminate bone inside the gut cavity of a Velociraptor." [65]	An azhdarchid.

Turtles

Genus	Species	Location	Material	Notes	Images
Nanhsiungchelyidae indet.	Indeterminate	Abdrant Nuru	"Three shell fragments." [66]	A nanhsiungchelyid.
	Indeterminate	Bayn Dzak	"Partial shells." [66]	A nanhsiungchelyid.
	Indeterminate	Udyn Sayr	"Two shell fragments." [66]	A nanhsiungchelyid.
Zangerlia	Z. dzamynchondi	Zamyn Khondt	"Partial shell." [67]	A nanhsiungchelyid.
	Z. ukhaachelys	Ukhaa Tolgod	"Partial skull and skeleton." [68]	A nanhsiungchelyid.

Dinosaurs

Alvarezsaurs

Genus	Species	Location	Material	Notes	Images
Alvarezsauridae indet.	Indeterminate	Tugriken Shireh	"Partial skull, braincase, and skeleton elements of two specimens." [69] [70]	An alvarezsaurid also known as the Tugriken Shireh alvarezsaur. Uncertainly referred as Parvicursor sp. [70]
Kol	K. ghuva	Ukhaa Tolgod	"A well-preserved right foot." [71]	A large alvarezsaurid. Its classification has been criticized. [72]
Shuvuuia	S. deserti	Ukhaa Tolgod	"Multiple specimens with skull and skeletons." [73] [74] [75] [76] [77]	An alvarezsaurid.
Undescribed Alvarezsauridae	Indeterminate	Bayn Dzak	"Partial pelvic girdle and hindlimb." [78]	An alvarezsaurid.
	Indeterminate	Gilvent Wash	Not given. [76]	An alvarezsaurid.

Ankylosaurids

Genus	Species	Location	Material	Notes	Images
Minotaurasaurus	M. ramachandrani	Ukhaa Tolgod	[Two] complete skulls, mandibles, and first cervical half-ring. [79] [80]	An ankylosaurid previously thought to be a junior synonym of Tarchia, but is now considered to be a valid and distinct taxon.
Pinacosaurus	P. grangeri	Bayn Dzak, Ukhaa Tolgod	[Three] skulls, mandibles, predentary, cervical vertebrae, dorsal vertebrae, caudal vertebrae, ribs, scapula, coracoids, humerus, radius, ulna, ilium, femora, tibia, fibula, pelvis, manus, tail club handles, cervical half-rings, osteoderms, and a nearly complete skeleton lacking a skull. [81] [82] [83]	An ankylosaurid also known from the Alagteeg Formation and Bayan Mandahu Formation.
Ankylosauridae indet.	Indeterminate	Zamyn Khondt	Partially complete postcranial skeleton with in situ osteoderms. [84]	Previously referred to Saichania, but is now referred to as Ankylosauridae indet., or cf. Pinacosaurus . [84]

Birds

Genus	Species	Location	Material	Notes	Images
Apsaravis	A. ukhaana	Ukhaa Tolgod	"Partial postcranial skeleton." [85]	A basal ornithurine bird.
Elsornis	E. keni	Tugriken Shireh	"Partial articulated skeleton lacking the skull." [86]	An enantiornithe.
Gobipteryx	G. minuta	Ukhaa Tolgod	"Partial skull." [87]	An enantiornithine. Also present in the Barun Goyot Formation.
Protoceratopsidovum'	P. fluxuosum	Bayn Dzak	"Partial eggs." [88]	Eggs probably laid by a bird. [89]
	P. minimum	Baga Tariach, Tugriken Shireh	"Clutch of four eggs and one pole of egg." [88]	Eggs probably laid by a bird. [89]
	P. sincerum	Bayn Dzak, Tugriken Shireh	"Multiple eggs and shells." [88]	Eggs probably laid by a bird. [89]
Styloolithus	S. sabathi	Bayn Dzak	"Partial to complete eggs." [89]	Eggs probably laid by a bird.

Ceratopsians

Genus	Species	Location	Material	Notes	Images
Bainoceratops	B. efremovi	Bayn Dzak	"Partial vertebrae." [90]	A protoceratopsid. May be synonymous with Protoceratops. [91]
Bagaceratops	Indeterminate	Udyn Sayr	"Skull with partial skeleton." [19]	A protoceratopsid. Indeterminate between Bagaceratops and Protoceratops. [19]
Protoceratops	P. andrewsi	Bayn Dzak, Tugriken Shireh, Udyn Sayr, Zamyn Khondt	"Multiple partial to complete specimens." [92] [7] [93] [8] [19]	A protoceratopsid.
	P. hellenikorhinus	Bor Tolgoi, Udyn Sayr	"Partial cranial remains." [94]	A protoceratopsid.
Protoceratopsidae indet.	Indeterminate	Ukhaa Tolgod	"Numerous skulls and remains." [95] [96]	A protoceratopsid.
Udanoceratops	U. tschizhovi	Udyn Sayr	"Skull and fragmented skeleton elements." [97]	A giant leptoceratopsid.

Dromaeosaurs

Genus	Species	Location	Material	Notes	Images
Tsaagan	T. mangas	Ukhaa Tolgod	"Skull and partial skeleton." [98]	A dromaeosaurid
Velociraptor	V. mongoliensis	Bayn Dzak, Chimney Buttes, Gilvent Wash, Tugriken Shireh, Udyn Sayr, Ukhaa Tolgod	"Multiple partial to complete specimens." [99] [100] [101] [102] [103] [104]	A dromaeosaurid.
Undescribed Dromaeosauridae	Indeterminate	Abdrant Nuru	"Claw." [105]	A dromaeosaurid.
	Indeterminate	Zos Wash	"Frontal region." [98]	A dromaeosaurid. Differs from Tsaagan . [98]

Hadrosaurs

Genus	Species	Location	Material	Notes	Images
Hadrosauroidea indet.	Indeterminate	Tugriken Shireh	"Fragmented remains from juveniles." [106] [107]	A hadrosauroid.
Plesiohadros	P. djadokhtaensis	Alag Teeg	"Skull and partial body elements." [107]	A hadrosauroid. Actually hails from the Alagteeg Formation. [108]

Halszkaraptorines

Genus	Species	Location	Material	Notes	Images
Halszkaraptor	H. escuilliei	Ukhaa Tolgod	"Partial skeleton with complete skull." [109]	A halszkaraptorine.
Mahakala	M. omnogovae	Tugriken Shireh	"Fragmented skull and skeleton." [110]	A halszkaraptorine.

Ornithomimosaurs

Genus	Species	Location	Material	Notes	Images
Aepyornithomimus	A. tugrikinensis	Tugriken Shireh	"Nearly complete foot." [111]	An ornithomimid.
Ornithomimosauria indet.	Indeterminate	Ukhaa Tolgod	"Partial braincase, jaw tips, ribs, and vertebral fragments". [112] [113]	An ornithomimid.

Oviraptorosaurs

Genus	Species	Location	Material	Notes	Images
Avimimus	A. portentonsus	Udyn Sayr	"Partial skull and skeleton." [114] [115]	An avimimid. Its locality origin has been disputed and may hail from the Nemegt Formation. [116]
Citipati	C. osmolskae	Ukhaa Tolgod	"Multiple specimens with partial to nearly complete skeletons, an embryo, eggs and nesting individuals." [117] [118] [119] [27]	An oviraptorid.
Elongatoolithus	E. frustrabilis
	E. subtitectorius
Khaan	K. mckennai	Ukhaa Tolgod	"Several specimens with partial to complete skeletons and skulls." [118] [120] [28]	An oviraptorid.
Macroolithus	M. mutabilis		"Eggs."	Eggs probably laid by an oviraptorid
Oviraptor	O. philoceratops	Bayn Dzak	"Partial skeleton with skull, associated with a nest and juvenile." [121] [119] [27]	An oviraptorid.
Oviraptoridae indet.	Indeterminate	Zamyn Khondt	"Nearly complete skeleton with skull." [122]	An oviraptorid also known as the Zamyn Khondt oviraptorid. Uncertainly referred to Citipati . [118] [119]
	Indeterminate	Zamyn Khondt	"Nearly complete skull with atlas and axis." [123]	An oviraptorid.
	Indeterminate	Udyn Sayr	"Assemblage of individuals." [27]	An oviraptorid.
	Indeterminate	Not specified.	"Two skulls with characteristic high crest." [124] [125] [126]	An oviraptorid.

Pachycephalosaurs

Genus	Species	Location	Material	Notes	Images
Goyocephale	G. lattimorei	Boro Khovil	"Partial skull and skeleton." [127]	A pachycephalosaurid. Locality sediments may belong to this formation. [127] [128]
Prenocephale	P. prenes	Bayn Dzak	"Complete skull and partial postcranium of several specimens."	A pachycephalosaurid also known from the Nemegt Formation.

Troodontids

Genus	Species	Location	Material	Notes	Images
Almas	A. ukhaa	Ukhaa Tolgod	"Skull with partial skeleton." [129]	A troodontid.
Archaeornithoides	A. deinosauriscus	Bayn Dzak	"Partial skull." [130]	A troodontid? Uncertain relationships among coelurosaurs. [130] [131]
Byronosaurus	B. jaffei	Ukhaa Tolgod	"Skull and fragmentary skeleton." [132]	A troodontid.
Gobivenator	G. mongoliensis	Zamyn Khondt	"Almost complete skeleton." [133]	A troodontid.
Saurornithoides	S. mongoliensis	Bayn Dzak	"Skull with fragmentary skeleton." [134]	A troodontid.
Troodontidae indet.	Indeterminate	Ukhaa Tolgod	"Partial skeleton." [135]	A troodontid.
	Indeterminate	Ukhaa Tolgod	"Juvenile skulls, skeleton, and one nest." [136] [131]	A troodontid. Referred to either Almas, [137] [129] or Byronosaurus. [131]
	Indeterminate	Ukhaa Tolgod	"Fragmented skull and skeleton remains." [138]	A troodontid. Provisionally referred to Saurornithoides, [138] but now excluded. [134]
	Indeterminate	Ukhaa Tolgod	"Partial skull and skeletons from two specimens." [74]	A troodontid.

Tyrannosaurids

Genus	Species	Location	Material	Notes	Images
Tyrannosauridae indet.	Indeterminate	Bayn Dzak	Not specified. [32]	A tyrannosaurid.
	Indeterminate	Khongil	"Supraorbital, vertebra, rib, femur and metatarsals." [139]	A tyrannosaurid.
	Indeterminate	Not specified.	"Partial right ilium." [140]	A tyrannosaurid.
	Indeterminate	Not specified.	"Teeth." [20]	A tyrannosaurid.

Sauropods

Genus	Species	Location	Material	Notes	Images
Sauropoda indet.	Indeterminate	Not specified. [141]	Not specified. [141]	A sauropod.

Gallery

Panoramic view of the Flaming Cliffs (Bayn Dzak), type locality of the Djadochta Formation

• 
• 
• 
• 
• 

See also

• List of dinosaur-bearing rock formations
• List of fossil sites (with link directory)
• Barun Goyot Formation
• Bayan Mandahu Formation
• Nemegt Formation
• Fighting Dinosaurs

References

1. Berkey, C.P., Morris, F.K., 1927. Geology of Mongolia, Natural History of Central Asia. American Museum of Natural History, New York. p. 475.
2. Andrews, R. C. (1932). Reeds, C. A. (ed.). The New Conquest of Central Asia: a Narrative of the Explorations of the Central Asiatic Expeditions in Mongolia and China, 1921-1930. Vol. 1 (1st ed.). New York: American Museum of Natural History. pp. 1−549. OCLC   766770.
3. Dashzeveg, D. (1963). "Яйца динозавров" [Dinosaur eggs]. Priroda (in Russian). 9: 100.
4. Kurochkin, E. N.; Barsbold, R. (2000). "The Russian-Mongolian expeditions and research in vertebrate palaeontology" (PDF). In Benton, M. J.; Shishkin, M. A.; Unwin, D. M.; Kurochkin, E. N. (eds.). The Age of Dinosaurs in Russia and Mongolia. Cambridge University Press. p. 235−255.
5. Kielan-Jaworowska, Z.; Barsbold, R. (1972). "Narrative of the Polish-Mongolian Palaeontological Expeditions, 1967-1971" (PDF). Palaeontologia Polonica. 27: 1−12.
6. Barsbold, R. (2016). "The Fighting Dinosaurs: The position of their bodies before and after death". Paleontological Journal. 50 (12): 1412−1417. doi:10.1134/S0031030116120042. S2CID   90811750.
7. Fastovsky, D. E.; Weishampel, D. B.; Watabe, M.; Barsbold, R.; Tsogtbaatar, K.; Narmandakh, P. (2011). "A nest of Protoceratops andrewsi (Dinosauria, Ornithischia)". Journal of Paleontology. 85 (6): 1035−1041. doi:10.1666/11-008.1. JSTOR   41409110. S2CID   129085129.
8. Hone, D. W. E.; Farke, A. A.; Watabe, M.; Shigeru, S.; Tsogtbaatar, K. (2014). "A New Mass Mortality of Juvenile Protoceratops and Size-Segregated Aggregation Behaviour in Juvenile Non-Avian Dinosaurs". PLOS ONE. 9 (11): e113306. Bibcode:2014PLoSO...9k3306H. doi: 10.1371/journal.pone.0113306 . PMC   4245121 . PMID   25426957.
9. Dashzeveg, D.; Novacek, M. J.; Norell, M. A.; Clark, J. M.; Chiappe, L. M.; Davidson, A.; McKenna, M. C.; Dingus, L.; Swisher, C.; Perle, A. (1995). "Extraordinary preservation in a new vertebrate assemblage from the Late Cretaceous of Mongolia". Nature. 374 (6521): 446–449. Bibcode:1995Natur.374..446D. doi:10.1038/374446a0. S2CID   4245878.
10. Dingus, L.; Loope, D. B.; Dashzeveg, D.; Swisher III, C. C.; Minjin, C.; Novacek, M. J.; Norell, M. A. (2008). "The Geology of Ukhaa Tolgod (Djadokhta Formation, Upper Cretaceous, Nemegt Basin, Mongolia)". American Museum Novitates (3616): 1−40. doi:10.1206/442.1. hdl: 2246/5916 . S2CID   129735494.
11. Jerzykiewicz, T. (1997). "Djadokhta Formation". In Currie, P. J.; Padian, K. (eds.). Encyclopedia of Dinosaurs. San Diego: Academic Press. pp. 188−191. ISBN   978-0-12-226810-6.
12. Dashzeveg, D.; Dingus, L.; Loope, D. B.; Swisher III, C. C.; Dulam, T.; Sweeney, M. R. (2005). "New Stratigraphic Subdivision, Depositional Environment, and Age Estimate for the Upper Cretaceous Djadokhta Formation, Southern Ulan Nur Basin, Mongolia" (PDF). American Museum Novitates (3498): 1−31. doi:10.1206/0003-0082(2005)498[0001:NSSDEA]2.0.CO;2. hdl: 2246/5667 . S2CID   55836458.
13. Lefeld, J. (1971). "Geology of the Djadokhta Formation at Bayn Dzak (Mongolia)" (PDF). Palaeontologia Polonica. 25: 101−127.
14. Hasegawa, H.; Tada, R.; Ichinnorov, N.; Minjin, C. (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.
15. Fastovsky, D. E. (1997). "The Paleoenvironments of Tugrikin-Shireh (Gobi Desert, Mongolia) and Aspects of the Taphonomy and Paleoecology of Protoceratops (Dinosauria: Ornithishichia)". PALAIOS. 12 (1): 59−70. Bibcode:1997Palai..12...59F. doi:10.2307/3515294. JSTOR   3515294.
16. Watabe, M.; Tsogtbaatar, K.; Suzuki, S.; Saneyoshi, M. (2010). "Geology of dinosaur fossil-bearing localities (Jurassic and Cretaceous: Mesozoic) in the Gobi Desert: Results of the HMNS-MPC Joint Paleontological Expedition". Hayashibara Museum of Natural Sciences Research Bulletin. 3: 41–118.
17. Loope, D. B.; Dingus, L.; Swisher III, C. C.; Minjin, C. (1998). "Life and death in a Late Cretaceous dune field, Nemegt Basin, Mongolia" (PDF). Geology. 28 (1): 27−30. Bibcode:1998Geo....26...27L. doi:10.1130/0091-7613(1998)026<0027:LADIAL>2.3.CO;2.
18. Makovicky, P. J. (2008). "Telling time from fossils: a phylogeny-based approach to chronological ordering of paleobiotas". Cladistics. 24 (3): 350−351. doi: 10.1111/j.1096-0031.2007.00184.x .
19. Czepiński, Ł. (2020). "New protoceratopsid specimens improve the age correlation of the Upper Cretaceous Gobi Desert strata" (PDF). Acta Palaeontologica Polonica. 65 (3): 481−497. doi: 10.4202/app.00701.2019 .
20. Jerzykiewicz, T.; Currie, P. J.; Eberth, D. A.; Johnston, P. A.; Koster, E. H.; Zheng, J.-J. (1993). "Djadokhta Formation correlative strata in Chinese Inner Mongolia: an overview of the stratigraphy, sedimentary geology, and paleontology and comparisons with the type locality in the pre-Altai Gobi". Canadian Journal of Earth Sciences. 30 (10): 2180−2195. Bibcode:1993CaJES..30.2180J. doi:10.1139/e93-190.
21. Kirkland, J. I.; Bader, K. (2010). "Insect Trace Fossils Associated with Protoceratops Carcasses in the Djadokhta Formation (Upper Cretaceous), Mongolia". In Ryan, M. J.; Chinnery-Allgeier, B. J.; Eberth, D. A. (eds.). New Perspectives on Horned Dinosaurs: The Royal Tyrrell Museum Ceratopsian Symposium. Indiana University Press. pp. 509–519. ISBN   9780253353580. JSTOR   j.ctt16gzgng.
22. Matsumoto, Y.; Saneyoshi, M. (2010). "Bored dinosaur skeletons". The Journal of the Geological Society of Japan. 116 (1): I–II. doi: 10.5575/geosoc.116.1.I_II .
23. Takeuchi, M.; Saneyoshi, M.; Tsogtbaatar, K.; Mainbayar, B.; Ulziitseren, S. (2016). "Trace fossils on dinosaur skeletons from the Upper Cretaceous of Gobi desert, Mongolia". Bulletin of Research Institute of Natural Sciences, Okayama University of Science (46): 1−6.
24. Saneyoshi, M.; Watabe, M.; Suzuki, S.; Tsogtbaatar, K. (2011). "Trace fossils on dinosaur bones from Upper Cretaceous eolian deposits in Mongolia: Taphonomic interpretation of paleoecosystems in ancient desert environments". Palaeogeography, Palaeoclimatology, Palaeoecology. 311 (1–2): 38−47. Bibcode:2011PPP...311...38S. doi:10.1016/j.palaeo.2011.07.024.
25. Loope, D. B.; Mason, J. A.; Dingus, L. (1999). "Lethal Sandslides from Eolian Dunes". The Journal of Geology. 10 (6): 707–713. Bibcode:1999JG....107..707L. doi:10.1086/314377. PMID   10517885. S2CID   45715054.
26. Clark, J. M.; Norell, M. A.; Chiappe, L. M. (1999). "An oviraptorid skeleton from the Late Cretaceous of Ukhaa Tolgod, Mongolia, preserved in an avianlike brooding position over an oviraptorid nest". American Museum Novitates (3265): 1–36. hdl: 2246/3102 .
27. Norell, M. A.; Balanoff, A. M.; Barta, D. E.; Erickson, G. M. (2018). "A second specimen of Citipati osmolskae associated with a nest of eggs from Ukhaa Tolgod, Omnogov Aimag, Mongolia". American Museum Novitates (3899): 1−44. doi:10.1206/3899.1. hdl: 2246/6858 . S2CID   53057001.
28. Scott Persons IV, W.; Funston, G. F.; Currie, P. J.; Norell, M. A. (2015). "A possible instance of sexual dimorphism in the tails of two oviraptorosaur dinosaurs". Scientific Reports. 5 (9472): 16247. Bibcode:2015NatSR...5E9472P. doi: 10.1038/srep09472 . PMC   4379468 . PMID   25824625.
29. Keqin, G.; Norell, M. A. (2000). "Taxonomic composition and systematics of late Cretaceous lizard assemblages from Ukhaa Tolgod and adjacent localities, Mongolian Gobi Desert". American Museum Novitates (249): 1−118. doi:10.1206/0003-0090(2000)249<0001:TCASOL>2.0.CO;2. hdl: 2246/1596 . S2CID   129367764.
30. Longrich, N. R. (2010). "The Function of Large Eyes in Protoceratops: A Nocturnal Ceratopsian?". In Ryan, M. J.; Chinnery-Allgeier, B. J.; Eberth, D. A. (eds.). New Perspectives on Horned Dinosaurs: The Royal Tyrrell Museum Ceratopsian Symposium. Indiana University Press. pp. 308−327. ISBN   978-0-253-35358-0.
31. Kielan-Jaworowska, Z.; Hurum, J. H.; Badamgarav, D. (2003). "An extended range of the multituberculate Kryptobaatar and distribution of mammals in the Upper Cretaceous of the Gobi Desert" (PDF). Acta Palaeontologica Polonica. 48 (2): 273−278.
32. Longrich, N. R.; Currie, P. J.; Dong, Z. (2010). "A new oviraptorid (Dinosauria: Theropoda) from the Upper Cretaceous of Bayan Mandahu, Inner Mongolia". Palaeontology. 53 (5): 945−960. doi: 10.1111/j.1475-4983.2010.00968.x .
33. Weishampel, David B.; Barrett, Paul M.; Coria, Rodolfo A.; Le Loueff, Jean; Xu, Xing; Zhao, Xijin; Sahni, Ashok; Gomani, Emily M.P.; Noto, Christopher N. (2004). "Dinosaur distribution". In Weishampel, David B.; Dodson, Peter; Osmólska, Halszka (eds.). The Dinosauria (Second ed.). Berkeley: University of California Press. pp. 596–598. ISBN   978-0-520-24209-8.
34. Naugolnykh, S. V. (2016). "Upper Cretaceous Paleosols of the Bain Dzak Section, Southern Mongolia". Paleontological Journal. 50 (12): 1451−1469. doi:10.1134/s0031030116120133. S2CID   133243515.
35. Roček, Z. (2008). "The Late Cretaceous frog Gobiates from Central Asia: its evolutionary status and possible phylogenetic relationships" (PDF). Cretaceous Research. 29 (4): 577−591. doi:10.1016/j.cretres.2008.01.005.
36. Efimov, N. B. (1983). "Review of crocodilians from Mongolia". Transactions of the Joint Soviet Mongolian Paleontological Expedition (in Russian). 24: 79−96.
37. Osmólska, H. (1972). "Preliminary note on a crocodilian from the Upper Cretaceous of Mongolia" (PDF). Palaeontologia Polonica. 27: 43−47.
38. Osmólska, H.; Hua, S.; Buffetaut, E. (1997). "Gobiosuchus kielanae (Protosuchia) from the Late Cretaceous of Mongolia: anatomy and relationships" (PDF). Acta Palaeontologica Polonica. 42 (2): 257−289.
39. Efimov, M. B. (193). "Revision of fossil crocodiles of Mongolia". Transactions of the Joint Soviet-Mongolian Paleontological Expedition (in Russian). 24: 76−94.
40. Efimov, M. B. (1988). "The fossil crocodiles and champsosaurides of Mongolia and USSR". Transactions of the Joint Soviet-Mongolian Paleontological Expedition (in Russian). 36: 5−105.
41. Pol, D.; Turner, A. H.; Norell, M. A. (2009). "Morphology of the late Cretaceous crocodylomorph Shamosuchus djadochtaensis and a discussion of neosuchian phylogeny as related to the origin of Eusuchia". Bulletin of the American Museum of Natural History (324): 1−103. doi:10.1206/0003-0090-324.1.1. hdl: 2246/5977 . OCLC   421118402. S2CID   83551788.
42. Turner, A. H. (2015). "A review of Shamosuchus and Paralligator (Crocodyliformes, Neosuchia) from the Cretaceous of Asia". PLOS ONE. 10 (2): e0118116. Bibcode:2015PLoSO..1018116T. doi: 10.1371/journal.pone.0118116 . PMC   4340866 . PMID   25714338.
43. Sulimski, A. (1978). "New data on the genus Adamisaurus Sulimski 1972 (Sauria) from the Upper Cretaceous of Mongolia" (PDF). Palaeontologica Polonica. 58: 43−56.
44. Alifanov, V. R. (1993). "Новые ящерицы семейства Macrocephalosauridae (Sauria) из верхнего мела Монголии и критические замечания о системе Teiidae (sensu Estes, 1983)" [New lizards of the family Macrocephalosauridae (Sauria) from the Upper Cretaceous of Mongolia, critical remarks on the systematics of the Teiidae (sensu Estes, 1983)](PDF). Paleontological Journal (in Russian). 27 (1): 57−74.
45. Alifanov, V. R. (1989). "New priscagamas (Lacertilia) from the Upper Cretaceous of Mongolia and their systematic position in the Iguania". Paleontological Journal (in Russian). 4: 73−87.
46. Norell, M. A.; Gao, K.-Q.; Conrad, J. L. (2008). "A new platynotan lizard (Diapsida: Squamata) from the Late Cretaceous Gobi Desert (Ömnögov), Mongolia" (PDF). American Museum Novitates (3605): 1−22. doi:10.1206/0003-0082(2008)3605[1:ANPLDS]2.0.CO;2. hdl: 2246/5910 . S2CID   86423607.
47. Conrad, J. L.; Norell, M. A. (2007). "A Complete Late Cretaceous Iguanian (Squamata, Reptilia) from the Gobi and Identification of a New Iguanian Clade" (PDF). American Museum Novitates (3584): 1−19. doi:10.1206/0003-0082(2007)3584[1:ACLCIS]2.0.CO;2. hdl: 2246/5877 . S2CID   83407564.
48. Gilmore, C. W. (1943). "Fossil lizards of Mongolia". Bulletin of the American Museum of Natural History. 81: 361–384.
49. Trofimov, B. A; Szalay, F. S. (1994). "New Cretaceous marsupial from Mongolia and the early radiation of Metatheria" (PDF). Proceedings of the National Academy of Sciences of the United States of America. 91 (26): 12569−12573. Bibcode:1994PNAS...9112569T. doi: 10.1073/pnas.91.26.12569 . JSTOR   2366383. PMC   45480 . PMID   7809079.
50. Kielan-Jaworowska (1974). "Multituberculate succession in the Late Cretaceous of the Gobi Desert (Mongolia)". Palaeontologica Polonica30: 23-44.
51. Gregory, W. K.; Simpson, G. G. (1926). "Cretaceous Mammal Skulls from Mongolia" (PDF). American Museum Novitates (225): 698–699. Bibcode:1926Natur.118..698G. doi:10.1038/118698a0. hdl: 2246/3193 . S2CID   38785853.
52. Rougier, G. W.; Wible, J. R.; Novacek, M. J. (1998). "Implications of Deltatheridium specimens for early marsupial history". Nature. 396 (6710): 459–463. Bibcode:1998Natur.396..459R. doi:10.1038/24856. PMID   9853752. S2CID   204996216.
53. Simpson, G. G. (1925). "A Mesozoic mammal skull from Mongolia" (PDF). American Museum Novitates (201): 1–12. hdl: 2246/3185 .
54. Kielan-Jaworowska, Z.; Hurum, J. H. (1997). "Djadochtatheria: a new suborder of multituberculate mammals" (PDF). Acta Palaeontologica Polonica. 42 (2): 201–242.
55. Kielan-Jaworowska, Z. (1969). "New Upper Cretaceous multituberculate genera from Bayn Dzak, Gobi Desert" (PDF). Palaeontologica Polonica. 21: 35–49.
56. Kielan-Jaworowska, Z. (1968). "Preliminary data on the Upper Cretaceous eutherian mammals from Bayn Dzak, Gobi Desert" (PDF). Palaeontologica Polonica. 19: 171–191.
57. Kielan-Jaworowska, Z.; Cifelli, R. L.; Luo, Z.-X. (2004). Mammals from the Age of Dinosaurs: Origins, Evolution, and Structure. New York: Columbia University Press. doi:10.7312/kiel11918. ISBN   9780231119184. JSTOR   10.7312/kiel11918.
58. Wible, J. R.; Rougier, G. W.; Novacek, M. J.; Ashek, R. J. (2007). "Cretaceous eutherians and Laurasian origin for placental mammals near the K/T boundary". Nature. 447 (7147): 1003−1006. Bibcode:2007Natur.447.1003W. doi:10.1038/nature05854. PMID   17581585. S2CID   4334424.
59. Rougier, G. W.; Sheth, A. S.; Spurlin, B. K.; Bolortsetseg, M.; Novacek, M. J. (2016). "Craniodental anatomy of a new Late Cretaceous multituberculate mammal from Udan Sayr, Mongolia" (PDF). Palaeontologica Polonica. 67 (3): 197−248. doi: 10.18297/ETD/1317 .
60. Rougier, G. W.; Novacek, M. J.; Dashzeveg, D. (1997). "A New Multituberculate from the Late Cretaceous Locality Ukhaa Tolgod, Mongolia. Considerations on Multituberculate Interrelationships" (PDF). American Museum Novitates (3191): 1–26. hdl: 2246/3591 .
61. Novacek, M. J.; Rougier, G. W.; Wible, J. R.; McKenna, M. C.; Dashzeveg, D.; Horovitz, I. (1997). "Epipubic bones in eutherian mammals from the Late Cretaceous of Mongolia". Nature. 389 (6650): 483−486. Bibcode:1997Natur.389..483N. doi:10.1038/39020. PMID   9333234. S2CID   205026882.
62. Horovitz, I. (2000). "The tarsus of Ukhaatherium nessovi (Eutheria, Mammalia) from the Late Cretaceous of Mongolia: an appraisal of the evolution of the ankle in basal therians". Journal of Vertebrate Paleontology. 20 (3): 547−560. doi:10.1671/0272-4634(2000)020[0547:TTOUNE]2.0.CO;2. JSTOR   4524126. S2CID   86031996.
63. Horovitz, I. (2003). "Postcranial skeleton of Ukhaatherium nessovi (Eutheria, Mammalia) from the Late Cretaceous of Mongolia". Journal of Vertebrate Paleontology. 23 (4): 857−868. doi:10.1671/2399-10. JSTOR   4524387. S2CID   85809847.
64. Wible, J. R.; Novacek, M. J.; Rougier, G. W. (2004). "New data on the skull and dentition in the Mongolian Late Cretaceous eutherian mammal Zalambdalestes" (PDF). Bulletin of the American Museum of Natural History. 281 (281): 1−144. doi:10.1206/0003-0090(2004)281<0001:NDOTSA>2.0.CO;2. hdl: 2246/449 . S2CID   83491778.
65. Hone, D.; Tsuihiji, T.; Watabe, M.; Tsogtbaatr, K. (2012). "Pterosaurs as a food source for small dromaeosaurs". Palaeogeography, Palaeoclimatology, Palaeoecology. 331–332: 27. Bibcode:2012PPP...331...27H. doi:10.1016/j.palaeo.2012.02.021.
66. Danilov, I. G.; Syromyatnikova, E. (2008). "New materials on turtles of the family Nanhsiungchelyidae from the Cretaceous of Uzbekistan and Mongolia, with a review of the nanhsiungchelyid record in Asia" (PDF). Proceedings of the Zoological Institute RAS. 312 (1–2): 3–25. doi:10.31610/trudyzin/2008.312.1-2.3. S2CID   130642652.
67. Sukhanov, V. B.; Narmandakh, P. (2006). "New taxa of Mesozoic turtles from Mongolia". Fossil Turtle Research. 1: 119−127.
68. Joyce, W. G.; Norell, M. A. (2005). "Zangerlia ukhaachelys, New Species, a Nanhsiungchelyid Turtle from the Late Cretaceous of Ukhaa Tolgod, Mongolia" (PDF). American Museum Novitates (3481): 1−19. doi:10.1206/0003-0082(2005)481[0001:ZUNSAN]2.0.CO;2. hdl: 2246/5672 . S2CID   54948634.
69. Suzuki, Chiappe, Dyke, Watabe, Barsbold and Tsogtbaatar, 2002. A new specimen of Shuvuuia deserti Chiappe et al., 1998, from the Mongolian Late Cretaceous with a discussion of the relationships of alvarezsaurids to other theropod dinosaurs. Contributions in Science. 494, 1-18.
70. Longrich & Currie (2009). Albertonykus borealis, a new alvarezsaur (Dinosauria: Theropoda) from the Early Maastrichtian of Alberta, Canada: Implications for the systematics and ecology of the Alvarezsauridae. Cretaceous Research. 30(1), 239-252.
71. Turner, A.H.; Nesbitt, S.J.; Norell, M.A. (2009). "A Large Alvarezsaurid from the Cretaceous of Mongolia". American Museum Novitates (3648): 1–14. doi:10.1206/639.1. hdl:2246/5967. S2CID   59459861.
72. Federico L. Agnolin; Jaime E. Powell; Fernando E. Novas; Martin Kundrát (2012). "New alvarezsaurid (Dinosauria, Theropoda) from uppermost Cretaceous of north-western Patagonia with associated eggs". Cretaceous Research. 35: 33–56. doi:10.1016/j.cretres.2011.11.014.
73. Chiappe, L.M., Norell, M. A., and Clark, J. M. (1998). "The skull of a relative of the stem-group bird Mononykus." Nature, 392 (6673): 275-278.
74. Dufeau, 2003. The cranial anatomy of the theropod dinosaur Shuvuuia deserti (Coelurosauria: Alvarezsauridae), and its bearing upon coelurosaurian phylogeny. Masters Thesis, The University of Texas at Austin. 275 pp.
75. Pei, 2015. New paravian fossils from the Mesozoic of east Asia and their bearing on the phylogeny of the Coelurosauria. PhD thesis, Columbia University. 545 pp.
76. Turner, A.H.; Nesbitt, S.J.; Norell, M.A. (2009). "A Large Alvarezsaurid from the Cretaceous of Mongolia". American Museum Novitates (3648): 1−14. doi:10.1206/639.1. hdl:2246/5967. S2CID   59459861.
77. Saitta, E., Fletcher, I., Martin, P.G., Pittman, M., Kaye, T., True, L., Norell, M., Abbott, G., Summons, R., Penkman, K., & Vinther, J. (2018). Preservation of feather fibers from the Late Cretaceous dinosaur Shuvuuia deserti raises concern about immunohistochemical analyses on fossils. Organic Geochemistry. 125: 142-151.
78. Norell, Chiappe and Clark, (1993). New limb on the avian family tree. Natural History. September, 38-43.
79. Alicea, J.; Loewen, M. (2013). "New Minotaurasaurus material from the Djodokta Formation establishes new taxonomic and stratigraphic criteria for the taxon" (PDF). Journal of Vertebrate Paleontology. Program and Abstracts: 76.
80. Penkalski, P.; Tumanova, T. (2017). "The cranial morphology and taxonomic status of Tarchia (Dinosauria: Ankylosauridae) from the Upper Cretaceous of Mongolia". Cretaceous Research. 70: 117−12. doi:10.1016/j.cretres.2016.10.004.
81. Gilmore, C. W. (1933). "Two new dinosaurian reptiles from Mongolia with notes on some fragmentary specimens". American Museum Novitates (679): 1–20. hdl:2246/2076.
82. Hill, R. V.; Witmer, L. W.; Norell, M. A. (2003). "A New Specimen of Pinacosaurus grangeri (Dinosauria: Ornithischia) from the Late Cretaceous of Mongolia: Ontogeny and Phylogeny of Ankylosaurs" (PDF). American Museum Novitates (3395): 1−29. doi:10.1206/0003-0082(2003)395<0001:ANSOPG>2.0.CO;2. hdl: 2246/2821 . S2CID   3253690.
83. Currie, P. J.; Badamgarav, D.; Koppelhus, E. B.; Sissons, R.; Vickaryous, M. K. (2011). "Hands, feet and behaviour in Pinacosaurus (Dinosauria: Ankylosauridae)" (PDF). Acta Palaeontologica Polonica. 56 (3): 489−504. doi: 10.4202/app.2010.0055 . S2CID   129291148.
84. Arbour, V. M.; Currie, P. J. (2013). "The taxonomic identity of a nearly complete ankylosaurid dinosaur skeleton from the Gobi Desert of Mongolia". Cretaceous Research. 46: 24−30. doi:10.1016/j.cretres.2013.08.008.
85. Clarke, Julia A., Norell, Mark A. (2002). "The morphology and phylogenetic position of Apsaravis ukhaana from the Late Cretaceous of Mongolia". American Museum Novitates, No. 3387, American Museum of Natural History, New York, NY.
86. Chiappe, L. M.; Suzuki, S.; Dyke, G. J.; Watabe, M.; Tsogtbaatar, K.; Barsbold, R. (2007). "A new Enantiornithine bird from the Late Cretaceous of the Gobi desert". Journal of Systematic Palaeontology. 5 (2): 193−208. doi:10.1017/S1477201906001969. S2CID   85391743.
87. Chiappe, L, M.; Norell M. A.; Clark, J. M. (2001). A new skull of Gobipteryx minuta (Aves: Enantiornithes) from the Cretaceous of the Gobi Desert. American Museum Novitates. 3346, 1-15.
88. Mikhailov, K. E. (1994). "Theropod and protoceratopsian dinosaur eggs from the Cretaceous of Mongolia and Kazakhstan". Paleontological Journal. 28 (2): 101−120.
89. Varricchio, D.J.; Barta, D.E. (2015). "Revisiting Sabath's "Larger Avian Eggs" from the Gobi Cretaceous". Acta Palaeontologica Polonica. 60 (1): 11–25.
90. Tereshchenko, V.; Alifanov, V. R. (2003). "Bainoceratops efremovi, a New Protoceratopid Dinosaur (Protoceratopidae, Neoceratopsia) from the Bain-Dzak Locality (South Mongolia)". Paleontological Journal. 37 (3): 293–302.
91. Makovicky, P. J.; Norell, M. A. (2006). "Yamaceratops dorngobiensis, a New Primitive Ceratopsian (Dinosauria: Ornithischia) from the Cretaceous of Mongolia" (PDF). American Museum Novitates (3530): 1–42. doi:10.1206/0003-0082(2006)3530[1:YDANPC]2.0.CO;2. hdl: 2246/5808 .
92. Brown, B.; Schlaikjer, E. M. (1940). "The Structure and Relationships of Protoceratops". Annals of the New York Academy of Sciences. 40 (3): 133−266. Bibcode:1940NYASA..40..133B. doi:10.1111/j.2164-0947.1940.tb00068.x. OCLC   1673730.
93. Handa, N.; Watabe, M.; Tsogtbaatar, K. (2012). "New Specimens of Protoceratops (Dinosauria: Neoceratopsia) from the Upper Cretaceous in Udyn Sayr, Southern Gobi Area, Mongolia". Paleontological Research. 16 (3): 179−198. doi:10.2517/1342-8144-16.3.179. S2CID   130903035.
94. Chiba, K.; Ryan, M. J.; Saneyoshi, M.; Konishi, S.; Yamamoto, Y.; Mainbayar, B.; Tsogtbaatar, K. (2020). "Taxonomic re-evaluation of Protoceratops (Dinosauria: Ceratopsia) specimens from Udyn Sayr, Mongolia" (PDF). Journal of Vertebrate Paleontology. Program and Abstracts.
95. Czepiński, Ł. (2019). "Ontogeny and variation of a protoceratopsid dinosaur Bagaceratops rozhdestvenskyi from the Late Cretaceous of the Gobi Desert" (PDF). Historical Biology. 32 (10): 1394–1421. doi:10.1080/08912963.2019.1593404. S2CID   132780322. Archived from the original (PDF) on 2021-07-08. Retrieved 2021-07-03.
96. Prieto-Márquez, A.; Garcia-Porta, J.; Joshi, S. H.; Norell, M. A.; Makovicky, P. J. (2020). "Modularity and heterochrony in the evolution of the ceratopsian dinosaur frill". Ecology and Evolution. 10 (13): 6288–6309. doi: 10.1002/ece3.6361 . PMC   7381594 . PMID   32724514.
97. Kurzanov, S. M. (1992). "A giant protoceratopsid from the Upper Cretaceous of Mongolia". Paleontological Journal (in Russian): 81−93.
98. Norell, M.A.; Clark, J.M.; Turner, A.H.; Makovicky, P.J.; Barsbold, R.; Rowe, T. (2006). "A new dromaeosaurid theropod from Ukhaa Tolgod (Omnogov, Mongolia)". American Museum Novitates (3545): 1–51. doi:10.1206/0003-0082(2006)3545[1:ANDTFU]2.0.CO;2. hdl:2246/5823. ISSN   0003-0082.
99. Norell and Makovicky, 1997. Important features of the dromaeosaur skeleton: Information from a new specimen. American Museum Novitates. 3215, 28 pp.
100. Barsbold and Osmólska, 1999. The skull of Velociraptor (Theropoda) from the Late Cretaceous of Mongolia. Acta Palaeontologica Polonica. 44(2), 189-219.
101. Norell and Makovicky, 1999. Important features of the dromaeosaurid skeleton II: Information from newly collected specimens of Velociraptor mongoliensis. American Museum Novitates. 3282, 45 pp.
102. Watabe and Tsogtbaatar, 2004. Report on the Japan - Mongolia Joint Paleontological Expedition to the Gobi desert, 2000. Hayashibara Museum of Natural Sciences Research Bulletin. 2, 45-67.
103. Turner, Makovicky and Norell, 2007. Feather quill knobs in the dinosaur Velociraptor. Science. 317, 1721.
104. David Hone; Jonah Choiniere; Corwin Sullivan; Xing Xu; Michael Pittman; Qingwei Tan (2010). New evidence for a trophic relationship between the dinosaurs Velociraptor and Protoceratops. , 291(3-4), 0−492. doi:10.1016/j.palaeo.2010.03.028.
105. Watabe and Suzuki, (2000). Report on the Japan - Mongolia Joint Paleontological Expedition to the Gobi desert, 1996. Hayashibara Museum of Natural Sciences Research Bulletin. 1, 58-68.
106. Barsbold, R.; Perle, A. (1983). "On taphonomy of joint burial of juvenile dinosaurs and some aspects of their ecology". Transactions of the Joint Soviet-Mongolian Paleontological Expedition (in Russian). 24: 121−125.
107. Tsogtbaatar, K.; Weishampel, D.; Evans, D. C.; Watabe, M. (2014). "A New Hadrosauroid (Plesiohadros djadokhtaensis) from the Late Cretaceous Djadokhtan Fauna of Southern Mongolia". In Eberth, D. A.; Evans, D. C. (eds.). Hadrosaurs. Indiana University Press. pp. 108−135. ISBN   978-0-253-01385-9.
108. Hasegawa, H.; Tada, R.; Ichinnorov, N.; Minjin, C. (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.
109. Cau, A.; Beyrand, V.; Voeten, D. F. A. E.; Fernandez, V.; Tafforeau, P.; Stein, K.; Barsbold, R.; Tsogtbaatar, K.; Currie, P. J.; Godefroit, P. (2017). "Synchrotron scanning reveals amphibious ecomorphology in a new clade of bird-like dinosaurs" (PDF). Nature. 552 (7685): 395−399. Bibcode:2017Natur.552..395C. doi:10.1038/nature24679. PMID   29211712. S2CID   4471941. Archived from the original (PDF) on 2021-07-08. Retrieved 2021-07-03.
110. Turner, A. H.; Pol, D.; Clarke, J. A.; Erickson, G. M.; Norell, M. A. (2007). "A Basal Dromaeosaurid and Size Evolution Preceding Avian Flight". Science. 317 (5843): 1378−1381. Bibcode:2007Sci...317.1378T. doi: 10.1126/science.1144066 . PMID   17823350.
111. Chinzorig, T.; Kobayashi, Y.; Tsogtbaatar, K.; Currie, P. J.; Watabe, M.; Barsbold, R. (2017). "First Ornithomimid (Theropoda, Ornithomimosauria) from the Upper Cretaceous Djadokhta Formation of Tögrögiin Shiree, Mongolia". Scientific Reports. 7 (5835): 5835. Bibcode:2017NatSR...7.5835C. doi: 10.1038/s41598-017-05272-6 . PMC   5517598 . PMID   28724887.
112. Makovicky, P. J.; Norell, Mark A. (1998). "A partial ornithomimid briancase from Ukhaa Tolgod (Upper Cretaceous, Mongolia)". American Museum Novitates (3247): 1–16.
113. Ksepka, Daniel T.; Norell, Mark A. (2004). "Ornithomimosauria cranial material from Ukhaa Tolgod (Omnogov, Mongolia)". American Museum Novitates (3448): 1–4. doi:10.1206/0003-0082(2004)448<0001:ocmfut>2.0.co;2. hdl:2246/2813. ISSN   0003-0082. S2CID   55019144.
114. Kurzanov, S. M. (1981). "An unusual theropod from the Upper Cretaceous of Mongolia". Transactions, Joint Soviet–Mongolian Palaeontological Expedition (in Russian). 15: 39−49.
115. Funston, G. F.; Mendonca, S. E.; Currie, P. J.; Barsbold, R.; Barsbold, R. (2018). "Oviraptorosaur anatomy, diversity and ecology in the Nemegt Basin". Palaeogeography, Palaeoclimatology, Palaeoecology. 494: 101−120. Bibcode:2018PPP...494..101F. doi:10.1016/j.palaeo.2017.10.023.
116. Watabe, M.; Suzuki, S.; Tsogtbaatar, K. (2006). "Geological and geographical distribution of bird-like theropod, Avimimus in Mongolia". Journal of Vertebrate Paleontology. 26 (supp. 003): 136A−137A. doi:10.1080/02724634.2006.10010069. S2CID   220413406.
117. Norell, M. A.; Clark, J. M.; Dashzeveg, D.; Barsbold, R.; Chiappe, L. M.; Davidson, A. R.; McKenna, M. C.; Altangerel, P.; Novacek, M. J. (1994). "A theropod dinosaur embryo and the affinities of the Flaming Cliffs Dinosaur eggs". Science. 266 (5186): 779−782. Bibcode:1994Sci...266..779N. doi:10.1126/science.266.5186.779. JSTOR   2885545. PMID   17730398. S2CID   22333224.
118. Clark, J. M.; Norell, M. A.; Barsbold, R. (2001). "Two new oviraptorids (Theropoda: Oviraptorosauria) from the Late Cretaceous Djadokta Formation, Ukhaa Tolgod". Journal of Vertebrate Paleontology. 21 (2): 209–213. doi:10.1671/0272-4634(2001)021[0209:TNOTOU]2.0.CO;2. JSTOR   20061948. S2CID   86076568.
119. Clark, J. M.; Norell, M. A.; Rowe, T. (2002). "Cranial Anatomy of Citipati osmolskae (Theropoda, Oviraptorosauria), and a Reinterpretation of the Holotype of Oviraptor philoceratops" (PDF). American Museum Novitates (3364): 1−24. doi:10.1206/0003-0082(2002)364<0001:CAOCOT>2.0.CO;2. hdl: 2246/2853 . S2CID   52247789.
120. Balanoff, A. M.; Norell, M. A. (2012). "Osteology of Khaan mckennai (Oviraptorosauria, Theropoda)". Bulletin of the American Museum of Natural History. 372 (372): 1−77. doi:10.1206/803.1. hdl: 2246/6413 . OCLC   884738416. S2CID   86067306.
121. Osborn, H. F. (1924). "Three new Theropoda, Protoceratops zone, central Mongolia". American Museum Novitates (144): 1−12. hdl: 2246/3223 . OCLC   40272928.
122. Barsbold, R. (1981). "Bezzubyye khishchnyye dinozavry Mongolii" [Toothless carnivorous dinosaurs of Mongolia]. Transactions, Joint Soviet–Mongolian Palaeontological Expedition (in Russian). 15: 28−39. S2CID   195060070. Translated paper
123. Funston, G. F. (2019). "Chapter 4 – Oviraptoridae" (PDF). Anatomy, systematics, and evolution of Oviraptorosauria (Dinosauria, Theropoda) (PhD thesis). University of Alberta. pp. 446−556.
124. Jansen, S. O. K. (2008). Beak morphology in oviraptorids, based on extant birds and turtles (PDF) (Thesis). University of Oslo. pp. 1−48. hdl: 10852/11785 .
125. "Oviraptor philoceratops". WitmerLab Collections. 2012.
126. "Oviraptor philoceratops, skull and hand". Prehistoric Planet Store. 2021.
127. Perle, A.; Maryańska, T.; Osmólska, H. (1982). "Goyocephale lattimorei gen. et sp. n., a new flat-headed pachycephalosaur (Ornithischia, Dinosauria) from the Upper Cretaceous of Mongolia" (PDF). Acta Palaeontologica Polonica. 27 (1–4): 115−127.
128. Sullivan, R. M. (2006). "A taxonomic review of the Pachycephalosauridae (Dinosauria: Ornithischia)". New Mexico Museum of Natural History and Science Bulletin (35): 347–365.
129. Pei, R.; Norell, M.A.; Barta, D.E; Bever, G.S.; Pittman, M.; Xu, Xing (2017). "Osteology of a New Late Cretaceous Troodontid Specimen from Ukhaa Tolgod, Ömnögovi Aimag, Mongolia". American Museum Novitates (3889): 1–47. doi:10.1206/3889.1. S2CID   90883541.
130. Elżanowski, A.; Wellnhofer, P. (1992). "A new link between theropods and birds from the Cretaceous of Mongolia". Nature. 359 (6398): 821−823. Bibcode:1992Natur.359..821E. doi:10.1038/359821a0. S2CID   4350813.
131. Bever, G. S.; Norell, M. A. (2009). "The Perinate Skull of Byronosaurus (Troodontidae) with Observations on the Cranial Ontogeny of Paravian Theropods". American Museum Novitates (3657): 1−51. doi:10.1206/650.1. hdl: 2246/5980 .
132. Makovicky, P. J.; Norell, M. A.; Clark, J. M.; Rowe, T. E. (2003). "Osteology and Relationships of Byronosaurus jaffei (Theropoda: Troodontidae)" (PDF). American Museum Novitates (3402): 1–32. doi:10.1206/0003-0082(2003)402<0001:oarobj>2.0.co;2. hdl: 2246/2828 . S2CID   51824767.
133. Tsuihiji, T.; Barsbold, R.; Watabe, M.; Tsogtbaatar, K.; Chinzorig, T.; Fujiyama, Y.; Suzuki, S. (2014). "An exquisitely preserved troodontid theropod with new information on the palatal structure from the Upper Cretaceous of Mongolia". Naturwissenschaften. 101 (2): 131–142. Bibcode:2014NW....101..131T. doi:10.1007/s00114-014-1143-9. PMID   24441791. S2CID   13920021.
134. Norell, M. A.; Makovicky, P. J.; Bever, G. S.; Balanoff, A. M.; Clark, J. M.; Barsbold, R.; Rowe, T. (2009). "A review of the Mongolian Cretaceous dinosaur Saurornithoides (Troodontidae, Theropoda)". American Museum Novitates (3654): 1−63. doi:10.1206/648.1. hdl: 2246/5973 .
135. Prieto-Marquez, Bolortsetseg and Horner, 2011. A diminutive deinonychosaur (Dinosauria: Theropoda) from the Early Cretaceous of Oosh (Ovorkhangai, Mongolia). Alcheringa. 1-20.
136. Grellet-Tinner, G. (2005). "CHAPTER VII: An Egg Clutch of the Troodontid Byronosaurus jaffei from the Gobi Desert: Novel Perspectives on the Origin of the Avian Reproductive Physiology". A phylogenetic analysis of oological characters: A case study of saurischian dinosaur relationships and avian evolution (PhD thesis). University of Southern California. p. 105.
137. Pei, R.; Norell, M. A. (2011). "A new troodontid (Dinosauria: Theropoda) from the Late Cretaceous Djadokhta Formation of Mongolia". Journal of Vertebrate Paleontology. 31 (supp. 002): 172A. doi:10.1080/02724634.2011.10635174. S2CID   210915628.
138. Norell, M. A.; Hwang, S. H. (2004). "A Troodontid Dinosaur from Ukhaa Tolgod (Late Cretaceous Mongolia)" (PDF). American Museum Novitates (3446): 1−9. doi:10.1206/0003-0082(2004)446<0001:ATDFUT>2.0.CO;2. hdl: 2246/2811 . S2CID   10547745.
139. Watabe, M.; Tsogtbaatar, K. (2004). "Report on the Japan - Mongolia Joint Paleontological Expedition to the Gobi desert, 2000". Hayashibara Museum of Natural Sciences Research Bulletin. 2: 45−67.
140. Gilmore, C. W. (1933). "Two new dinosaurian reptiles from Mongolia with notes on some fragmentary specimens". American Museum Novitates (679): 1−20. hdl: 2246/2076 .
141. Jerzykiewicz, T.; Russell, D. A. (1991). "Late Mesozoic stratigraphy and vertebrates of the Gobi Basin". Cretaceous Research. 12 (4): 345−377. doi:10.1016/0195-6671(91)90015-5.