Udurchukan Formation
Geologic formation in Russia
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The Udurchukan Formation is a geological formation located in Amur Region, Far East Russia. Based on palynomorphs such as Wodehouseia spinata, the Udurchukan is considered of Maastrichtian age of the Late Cretaceous, during the Cretaceous Period.
| Udurchukan Formation | |
|---|---|
| Stratigraphic range: Maastrichtian ~ | |
| Type | Geological formation |
| Unit of | Tsagayan Group |
| Underlies | Bureya Formation |
| Overlies | Kundur Formation |
| Thickness | 11 metres (40 ft) exposed at Kundur locality |
| Lithology | |
| Primary | Conglomerate, mudstone, diamictite |
| Other | Sandstone |
| Location | |
| Coordinates | 49.5°N 129.5°E |
| Approximate paleocoordinates | 51.4°N 115.8°E |
| Region | Amur Oblast |
| Country | Russia |
| Extent | Zeya-Bureya Basin |
  Udurchukan Formation (Russia)  Udurchukan Formation (Amur Oblast) | |
Fossil record
Since Wodehouseia spinata and Aquillapollenites subtilis are known in the Americas only from the Late Maastrichtian, the presence of these palynomorphs in the Udurchukan caused Godefroit to consider the unit and its lambeosaur dominated fauna to be coeval with the Lance Formation and Hell Creek Formation. However, research in the Songliao Basin indicates Wodehouseia spinata is also known from the early (albeit not basal) and middle Maastrichtian of Asia.
Dinosaurs
Color key
|
Notes Uncertain or tentative taxa are in small text; |
Ornithischians
Ankylosaurs
| Ankylosaurs reported from the Udurchukan Formation | ||||||
|---|---|---|---|---|---|---|
| Taxon | Species | Location | Stratigraphic position | Material | Notes | Images |
| Nodosauridae[1] | indet. | Kundur | Upper | A tooth, an incomplete tooth and an osteo dermal scute. | An indeterminate nodosauridae. | |
Hadrosaurs
| Hadrosaurs reported from the Udurchukan Formation | ||||||
|---|---|---|---|---|---|---|
| Taxon | Species | Location | Stratigraphic position | Material | Notes | Images |
| Amurosaurus | A. riabinini | Blagoveschensk | A partial remnants of skull and lower jaw. | A lambeosaurine hadrosaur which was the most common dinosaur in the area, a bonebed containing many specimens was unearthed in 2008.[2] |  | |
| Kerberosaurus | K. manakini | Blagoveschensk | The caudal part of cranium consists of a braincase. | A saurolophine hadrosaur |  | |
| Kundurosaurus | K. nagornyi | Kundur | A partial, disarticulated skull. | A saurolophine hadrosaur; possibly synonymous with Kerberosaurus |  | |
| Hadrosaurinae | Indetermidate | |||||
| Olorotitan | O. arharensis | Kundur | A nearly complete skeleton. | A hadrosaur |  | |
Sauropods
| Sauropods reported from the Udurchukan Formation | ||||||
|---|---|---|---|---|---|---|
| Taxon | Species | Location | Stratigraphic position | Material | Notes | Images |
| Arkharavia[3] | A. heterocoelica | Kundur | Upper | A single tooth and a proximal tail vertebrae, although some remains probably belong to a hadrosaurid. | A Somphospondyli sauropod.[4] |  |
| Opisthocoelicaudiinae | Indetermidate. | |||||
| Titanosauria | Indetermidate | |||||
Theropods
| Theropods reported from the Udurchukan Formation | ||||||
|---|---|---|---|---|---|---|
| Taxon | Species | Location | Stratigraphic position | Material | Notes | Images |
| Albertosaurinae | Indetermidate | |||||
| Dromaeosaurinae | Indetermidate. | |||||
| Indeterminate. | ||||||
| Ornithomimidae[5] | Indetermidate. | Described as being very similar to Qiupalong[5] | ||||
| Richardoestesia | R. sp | |||||
| Saurornitholestes | S. cf. sp. | |||||
| Theropoda | Indeterminate | |||||
| Troodon | T. sp. | |||||
| Tyrannosaurinae | Indetermidate. | Similar in size to Tyrannosaurus[6] | ||||
Reptiles
| Reptiles reported from the Udurchukan Formation | ||||||
|---|---|---|---|---|---|---|
| Taxon | Species | Location | Stratigraphic position | Material | Notes | Images |
| Amuremys | A. planicostata | |||||
| Cimolodonta | indet. | |||||
| Crocodylia | indet. | |||||
| Lindholmemydidae | indet. | |||||
| Shamosuchus | S. sp. | |||||
| Testudines | indet. | |||||
| Trionychidae | indet. | |||||
Insects
| Plants reported from the Udurchukan Formation | ||||||
|---|---|---|---|---|---|---|
| Taxon | Species | Location | Stratigraphic position | Material | Notes | Images |
| Mesosigara | M. kryshtofovichi | |||||
Flora
| Plants reported from the Udurchukan Formation | ||||||
|---|---|---|---|---|---|---|
| Taxon | Species | Location | Stratigraphic position | Material | Notes | Images |
| Cupressinoxylon | C. sp. | |||||