Bayan Mandahu Formation | |
---|---|
Stratigraphic range: Campanian, | |
Type | Geological formation |
Unit of | Gobi Desert |
Lithology | |
Primary | Sandstone |
Location | |
Coordinates | 41.75N 106.75E |
Region | Inner Mongolia |
Country | China |
Type section | |
Named for | Bayan Mandahu, Urad Rear Banner, Inner Mongolia |
The Bayan Mandahu Formation (also known as Wulansuhai Formation or Wuliangsuhai Formation) is a geological unit of "redbeds" located near the village of Bayan Mandahu in Inner Mongolia and China (in the Gobi Desert) and dates from the late Cretaceous Period. Laid down in the Campanian, it is dated somewhat uncertainly to between 75 and 71 mya (million years ago). [1]
The paleoenvironment it preserves was semi-arid and characterized by alluvial (stream-deposited) and eolian (wind-deposited) sediments. The formation is known for its vertebrate fossils, most of which are preserved in unstructured sandstone, indicating burial by wind-blown sandstorms. [2]
The fauna of the Bayan Mandahu is very similar in composition to the nearby Djadochta Formation, and the two may have been deposited at roughly the same time. These two formations share many of the same genera, but differ in the makeup of species. For example, the most common mammal in the Djadochta is Kryptobaatar dashzevegi , while in the Bayan Mandahu, it is the closely related Kryptobaatar mandahuensis . Similarly, the dinosaur fauna of the Djadochta includes Protoceratops andrewsi and Velociraptor mongoliensis , while the Bayan Mandahu contains Protoceratops hellenikorhinus and Velociraptor osmolskae . [1]
Color key
| Notes Uncertain or tentative taxa are in small text; |
Crocodylomorphs of the Bayan Mandahu Formation | ||||||
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Genus | Species | Location | Material | Notes | Images | |
Shamosuchus [2] | A mesoeucrocodylian. | |||||
An amphisbaenian species is known from the formation. [2] An iguanian species is known from the formation. [2]
Lizards of the Bayan Mandahu Formation | ||||||
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Genus | Species | Location | Material | Notes | Images | |
Adamisaurus [2] | A. magnidentatus [2] | An agamid. | ||||
Bainguis [2] | A diploglossan. | |||||
Telmasaurus [2] | A monitor lizard. | |||||
Turtles of the Bayan Mandahu Formation | ||||||
---|---|---|---|---|---|---|
Genus | Species | Location | Material | Notes | Images | |
Basilemys [2] | A softshell turtle. | |||||
"Zangerlia" | "Z." neimongolensis | Bayan Mandahu | "Partial to complete skeletons of multiple individuals." [3] | A nanhsiungchelyid. | ||
A taeniolabidoidea multituberculate is known from the formation. [2]
Mammals of the Bayan Mandahu Formation | ||||||
---|---|---|---|---|---|---|
Genus | Species | Location | Material | Notes | Images | |
Guibaatar [4] | G. castellanus | A djadochtatheriid multituberculate. | ||||
Kennalestes [2] | K. gobiensis [2] | A placental. Also present in the Djadochta Formation. | ||||
Kryptobaatar [1] | K. mandahuensis | A multituberculate. | ||||
Genus | Species | Location | Material | Notes | Images |
---|---|---|---|---|---|
Alvarezsauridae indet. [5] | Indeterminate [5] | Bayan Mandahu [5] | An articulated series of partial anterior cervical vertebrae, an anterior cervical vertebra, isolated fragmentary anterior caudal vertebrae, a partial scapula, and pedal phalanges. [5] | An unnamed parvicursorine alvarezsaurid. [5] | |
Linhenykus | L. monodactylus [6] | Wuliangsuhai [6] | Cervical vertebrae, dorsal vertebrae, sacral vertebrae, caudal vertebrae, a scapulocoracoid, a sternum, much of the forelimbs, a partial pelvis, nearly complete hindlimbs, and some unidentified fragments. [6] | A monodactyl parvicursorine alvarezsaurid. [6] | |
Genus | Species | Location | Material | Notes | Images |
---|---|---|---|---|---|
Pinacosaurus | P. grangeri [7] | Bayan Mandahu [7] | [Four] juvenile specimens consisting of skulls, manidibles, cervical half-rings and almost complete skeletons, and an incomplete subadult skull. [7] | A basal ankylosaurine ankylosaurid also known from the Djadochta Formation. | |
P. mephistocephalus [8] | Bayan Mandahu [8] | A nearly complete articulated skeleton, with in situ cervical dermal armour and tail-club, that lies in a natural with limb bones doubled under the body. [8] | A basal ankylosaurine ankylosaurid. | ||
Genus | Species | Location | Material | Notes | Images |
---|---|---|---|---|---|
cf. Gobipteryx | Indeterminate | "Eggs similar to those attributed to Gobipteryx minuta from the Djadochta Formation." [2] | |||
Genus | Species | Location | Material | Notes | Images |
---|---|---|---|---|---|
Genus | Species | Location | Material | Notes | Images |
Bagaceratops | B. rozhdestvenskyi | Bayan Mandahu | A partial skull. [9] | A protoceratopsid also known from the Barun Goyot Formation and possibly the Djadochta Formation. | |
Magnirostris [1] | M. dodsoni [1] | Bayan Mandahu [10] | A partial skull. | A protoceratopsid now considered synonym of Bagaceratops. [9] | |
Protoceratops | P. hellenikorhinus [11] | Bayan Mandahu [11] | Skulls and sparse body remains from multiple individuals. [12] [11] | A protoceratopsid. | |
Udanoceratops ? | Indeterminate | Bayan Mandahu | "Nearly 1 meter long skull." [2] | A giant leptoceratopsid. Reported remains probably represent Protoceratops hellenikorhinus. [13] | |
Genus | Species | Location | Material | Notes | Images |
---|---|---|---|---|---|
Linheraptor [14] | L. exquisitus [14] | Wuliangsuhai [14] | A skull, cervical vertebrae, caudal vertebrae, a scapula, a humerus, a radius, metacarpals, manual phalanxes, sternal plate, a pubis, a femur, a tibiotarsus, metatarsals, and pedal phalanxes. [14] | A possible velociraptorine dromaeosaurid. [14] | |
Velociraptor | V. osmolskae [15] | Bayan Mandahu [1] | A paired maxillae and left lacrimal. [1] | A velociraptorine dromaeosaurid. [1] | |
Genus | Species | Location | Material | Notes | Images |
---|---|---|---|---|---|
Undescribed Hadrosauridae [10] | Indeterminate [10] | Bayan Mandahu [10] | A hadrosaurid. | ||
Genus | Species | Location | Material | Notes | Images |
---|---|---|---|---|---|
Machairasaurus | M. leptonychus [10] | Bayan Mandahu [10] | A nearly complete articulated right forearm and manus, pedal phalanges, manual phalanges, caudal vertebrae, dorsal ribs, chevrons, and fragments of metatarsals III and IV. [10] | A heyuanniine oviraptorid. [10] | |
Oviraptoridae indet. | Indeterminate | Bayan Mandahu | "Partial individual sitting atop an egg clutch." [16] | An oviraptorid that represent the second nesting oviraptorid. Sometimes referred to Machairasaurus. [10] [17] | |
Wulatelong | W. gobiensis [18] | Wuliangsuhai [18] | A partial skull, dorsal vertebrae, caudal vertebrae, partial scapulocoracoids, a partial sternum, a partial humerus, an incomplete manus, a nearly complete pelvic girdle, and the right hindlimb. [18] | A basal oviraptorid oviraptorosaur. [18] | |
Genus | Species | Location | Material | Notes | Images |
---|---|---|---|---|---|
Undescribed Sauropoda [10] | Indeterminate [10] | Bayan Mandahu [10] | A sauropod. | ||
Genus | Species | Location | Material | Notes | Images |
---|---|---|---|---|---|
Linhevenator [19] | L. tani [19] | Wuliangsuhai [19] | A skull and mandible, anterior dorsal vertebrae, middle dorsal vertebrae, a scapula, a humerus, incomplete ischia, a femur, nearly complete pes, and other fragmentary bones. [19] | A troodontid with short forearms. [19] | |
Papiliovenator | P. neimengguensis [20] | Bayan Mandahu [20] | An almost complete skull, cervical vertebrae, anterior dorsal vertebrae, partial scapulae, partial coracoid, fragmentary pelvic girdle, partial humeri, ulna, radius, partial manus, femur, tibia, fibula, pes, and a pedal phalanx II-3. [20] | A troodontid that is part of a clad that includes all other Late Cretaceous troodontids except Almas . [20] | |
Philovenator | P. curriei [21] | Wuliangsuhai [21] | A nearly complete femur, a partial tibia, a partial fibula, astragalus-calcaneum complex, distal tarsals, metatarsals, and pedal phalanges. [21] | A troodontid. [21] | |
Genus | Species | Location | Material | Notes | Images |
---|---|---|---|---|---|
Undescribed Tyrannosauridae [10] | Indeterminate [10] | Bayan Mandahu [10] | A tyrannosaurid. | ||
Velociraptor is a genus of small dromaeosaurid dinosaurs that lived in Asia during the Late Cretaceous epoch, about 75 million to 71 million years ago. Two species are currently recognized, although others have been assigned in the past. The type species is V. mongoliensis, named and described in 1924. Fossils of this species have been discovered in the Djadochta Formation, Mongolia. A second species, V. osmolskae, was named in 2008 for skull material from the Bayan Mandahu Formation, China.
Protoceratops is a genus of small protoceratopsid dinosaurs that lived in Asia during the Late Cretaceous, around 75 to 71 million years ago. The genus Protoceratops includes two species: P. andrewsi and the larger P. hellenikorhinus. The former was described in 1923 with fossils from the Mongolian Djadokhta Formation, and the latter in 2001 with fossils from the Chinese Bayan Mandahu Formation. Protoceratops was initially believed to be an ancestor of ankylosaurians and larger ceratopsians, such as Triceratops and relatives, until the discoveries of other protoceratopsids. Populations of P. andrewsi may have evolved into Bagaceratops through anagenesis.
Bagaceratops is a genus of small protoceratopsid dinosaurs that lived in Asia during the Late Cretaceous, around 72 to 71 million years ago. Bagaceratops remains have been reported from the Barun Goyot Formation and Bayan Mandahu Formation. One specimen may argue the possible presence of Bagaceratops in the Djadochta Formation.
Udanoceratops is a genus of large leptoceratopsid dinosaur that lived during the Late Cretaceous period of Mongolia.
The Barun Goyot Formation is a geological formation dating to the Late Cretaceous Period. It is located within and is widely represented in the Gobi Desert Basin, in the Ömnögovi Province of Mongolia.
The Djadochta Formation 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 and mammal remains are among the fossils recovered from the formation.
Tsaagan is a genus of dromaeosaurid dinosaur from the Djadokhta Formation of the Late Cretaceous of Mongolia.
Mahakala is a genus of halszkaraptorine theropod dinosaur from the Campanian-age Upper Cretaceous Djadokhta Formation of Ömnögovi, Mongolia. It is based on a partial skeleton found in the Gobi Desert. Mahakala was a small dromaeosaurid, and its skeleton shows features that are also found in early troodontids and avialans. Despite its late appearance, it is among the most basal dromaeosaurids. Its small size, and the small size of other basal deinonychosaurians, suggests that small size appeared before flight capability in birds. The genus is named for Mahakala, one of eight protector deities (dharmapalas) in Tibetan Buddhism.
The Iren Dabasu Formation is a Late Cretaceous geologic formation in the Iren Nor region of Inner Mongolia. Dinosaur remains diagnostic to the genus level are among the fossils that have been recovered from the formation. The formation was first described and defined by Henry Fairfield Osborn in 1922 and it is located in the Iren Nor region of China.
The Bayin-Gobi Formation is a geological formation in Inner Mongolia, north China, whose strata date back to Albian of the Early Cretaceous period. Dinosaur remains are among the fossils that have been recovered from the formation.
Minotaurasaurus is a monospecific genus of ankylosaurid dinosaur that lived in Mongolia during the Late Cretaceous in what is now the Djadochta Formation. The type and only species, Minotaurasaurus ramachandrani, is known from two skulls, a cervical vertebra and a cervical half ring. It was named and described in 2009 by Clifford Miles and Clark Miles. The first fossils of Minotaurasaurus were illegally exported out of Mongolia.It has been suggested to be a synonym of Tarchia but more recent publications consider it as a distinct genus.
Linheraptor is a genus of dromaeosaurid dinosaur which lived in what is now China in the Late Cretaceous. It was named by Xu Xing and colleagues in 2010, and contains the species Linheraptor exquisitus. This bird-like dinosaur was less than 2 m (6.5 ft) long and was found in Inner Mongolia. It is known from a single, nearly complete skeleton.
Machairasaurus is a genus of oviraptorid dinosaur which was found in the Bayan Mandahu Formation, China, dating to the late Cretaceous period.
Linhevenator is a genus of short-armed troodontid theropod dinosaur from the Late Cretaceous (Campanian) Bayan Mandahu Formation of Bayan Mandahu, Inner Mongolia, China.
Wulatelong is an extinct genus of basal oviraptorid dinosaur known from the Late Cretaceous Wulansuhai Formation of Bayan Mandahu, Linhe District of Inner Mongolia, northern China. It contains a single species, Wulatelong gobiensis.
This timeline of oviraptorosaur research is a chronological listing of events in the history of paleontology focused on the oviraptorosaurs, a group of beaked, bird-like theropod dinosaurs. The early history of oviraptorosaur paleontology is characterized by taxonomic confusion due to the unusual characteristics of these dinosaurs. When initially described in 1924 Oviraptor itself was thought to be a member of the Ornithomimidae, popularly known as the "ostrich" dinosaurs, because both taxa share toothless beaks. Early caenagnathid oviraptorosaur discoveries like Caenagnathus itself were also incorrectly classified at the time, having been misidentified as birds.
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The China-Canada Dinosaur Project was a six-year series of palaeontological expeditions carried out by scientists from China and Canada.