The Namagat Formation ( Namagatu , Nemegt ) is a geological formation (formation) in the Gobi Desert in Mongolia , up to the Upper Cretaceous . It overlaps the Baruun Goyot formation. The formation consists of sand channel beds and contains fossils of fish , turtles , crocodiles , birds and various dinosaurs . The climate here was wetter than in previous formations; there, apparently, there were small forests. Also, plant remains were found here [1] .
There is no absolute dating of the Namagat Formation. Most likely, it was an early Maastricht 71-69 million liters. n Paleontologist Gradzinsky and others consider the Campanian stage possible, but later studies show the opposite. The dating by the Campanian stage does not seem convincing anymore, since the Alag-Teeg layers (or lower Dyadokhta, in the area of Chuluut Uul) were radiometrically dated to approximately 73.5 million liters. n or even younger (newer - 71.6 ± 1.6 million years ago). With 73.5 (or possibly 72) million liters. n Alag-Teeg is separated from Nemagat by the "classical" Dyadokht (for example, Bayan Dzag), the late Dyadokht formation (Uhaa-Tolgod) and Baruun Goyot (Hulsan). All of these intermediate layers almost certainly represent an interval of more than 1.5 million years between Alag-Teeg and the beginning of Maastricht (72.1 million years ago, according to the latest dating). The presence of Saurolophus remains in the formation supports dating to the early Maastrichtian, as this genus occurs in the early Maastricht formation of the Horseshoe Canyon in America [2] .
Content
- 1 Description
- 2 Flora and fauna of the Namagat Formation
- 2.1 Coelurosauria
- 2.1.1 Oviraptorosauria
- 2.1.2 Paravia
- 2.1.3 Other coelurosaurs
- 2.2 Invertebrates
- 2.3 Mammals
- 2.4 Poultry
- 2.5 Zauropods
- 2.6 Fossil Eggs
- 2.1 Coelurosauria
- 3 See also
- 4 notes
Description
Namegat (upper layers) consists of shales and sandstones, which occur on the territory of ancient lakes, streams and floodplains. The Altan Ula area was described by Michael Novachek in 1996 as "a canyon carved from a very rich series of sedimentary rocks" with "steep cliffs and narrow erosions." The presence of petrified wood, and the remnants of Araucariaceae conifers indicate that in Maastricht, the Nemagat Depression is overgrown with forests, with a high canopy formed by tall conifers. An examination of the facies of the rocks of this formation suggests the presence of streams and a river bed, swamps and shallow lakes. Deposits also indicate that there was a rich habitat, with various food in large quantities, which was fed by massive Cretaceous dinosaurs . [3]
Namagat Flora and Fauna
Coelurosauria
Oviraptorosauria
| Oviraptorosaurs from the Namagat Formation | ||||||
|---|---|---|---|---|---|---|
| Kind | View | Location | Stratigraphic position | Material | Notes | Pictures |
Ajancingenia | Ajancingenia yanshini |
|
| "A partial skeleton with a skull [and five] fragments of a skeleton." [four] | Oviraptoride, also found in the Baruun Goyot formation. | Avimimus Rinchenia |
Avimimus | Avimimus portentosus | Avimimid. | ||||
Elmisaurus | Elmisaurus rarus | "[Three] legs [and] hand." [four] | Cenagnatide . | |||
Conchoraptor | C. gracilis |
|
| "Partial skeleton with a skull, [four] partial skulls, [and] fragmentary skull with a skeleton." [four] | Oviraptoride. | |
Nemegtomaia | Nemegtomaia barsboldi | Oviraptoride. | ||||
Nomingia | N. gobiensis | "Partial skeleton." [5] | ||||
Rinchenia | Rinchenia mongoliensis | "Skull and fragmented skeleton." [5] | Oviraptoride. | |||
Paravia
| Paravian of the Namagat Formation | ||||||
|---|---|---|---|---|---|---|
| Kind | View | Location | Stratigraphic position | Material | Notes | Pictures |
Adasaurus [6] | Adasaurus mongoliensis [6] | "Partial skull and skeleton." [7] | Dromaeosaurid. | Zanabazar | ||
Borogovia | Borogovia gracilicrus | "Partial legs." [8] | Troodontid. | |||
Gurilynia | Gurilynia nessovi | "Shoulder girdle and wing elements." [9] | Enantsiornithine. | |||
Judinornis | Judinornis nogontsavensis | "Vertebra." [10] | Hesperornithine. | |||
Saurornithoides | S. junior | Reclassified as Zanabazar junior | ||||
Teviornis | Teviornis gobiensis | Anseriform, related to modern ducks and geese. | ||||
Tochisaurus | Tochisaurus nemegtensis | Metatarsus. [8] | Troodontid. | |||
Zanabazar [11] | Zanabazar junior [6] | "Skull with a fragmented skeleton." [8] | Troodontid. | |||
Other coelurosaurs
| Other Namagt Coelurosaurs | ||||||
|---|---|---|---|---|---|---|
| Kind | View | Location | Stratigraphic position | Material | Notes | Pictures |
Alioramus [6] | Alioramus remotus [6] | Tyrannosaurus, now represented in the layers of Nogoon Tsav. The namegat remains are renamed A. altai . | Alioramus Deinocheirus Mononykus | |||
Alioramus altai | Tyrannosaurid. | |||||
Anserimimus | Anserimimus planinychus | "Incomplete skeleton." [12] | Ornithomimide. | |||
Bagaraatan | Bagaraatan ostromi | "Fragmented skull and related skeleton." [13] | An undefined classification coelurosaurus. | |||
Deinocheirus [6] | Deinocheirus mirificus [6] | "Hand elements, skull. Two new samples make up a relatively complete skeleton." [12] | Giant ornithomimosaurus. | |||
Gallimimus [6] | Gallimimus bullatus [6] | "[Three] Relatively complete skeleton, whole postcranial skeleton, skull with an associated skeleton, [and] other fragments of the skeleton.", [12] and two full skeletons " [14] | Ornithomimide. | |||
Mononykus | Mononykus olecranus | Alvareszavrid. | ||||
Raptorex [15] | Raptorex kreigsteni [15] | Tyrannosaurus, possibly Tarbosaurus . [16] | ||||
Tarbosaurus [6] | Tarbosaurus bataar [6] | "Skull and [two] skeletons [17] | Tyrannosaurid. | |||
Therizinosaurus [6] | Therizinosaurus cheloniformis [6] |
|
| "Elements of the arms [and] legs." [eighteen] | Giant Therizinosaurus. | |
Invertebrates
| Invertebrates from the Namagat Formation | ||||||
|---|---|---|---|---|---|---|
| Kind | View | Location | Stratigraphic position | Abundance | Notes | Pictures |
Nemegtia | Shell | |||||
Mammals
| Mammals from the Namagat Formation | ||||||
|---|---|---|---|---|---|---|
| Kind | View | Location | Stratigraphic position | Abundance | Notes | Pictures |
Buginbaatar | Buginbaatar transaltaiensis | Multi-tuberous | ||||
Poultry
| Namagat Poultry Dinosaurs | ||||||
|---|---|---|---|---|---|---|
| Kind | View | Location | Stratigraphic position | Material | Notes | Pictures |
Barsboldia | Barsboldia sicinskii | "Sacrum [and] pelvis." [19] | Hadrosauride. | Homalocephale . | ||
Dyoplosaurus | Dyoplosaurus giganteus | Ankylosaurus. Previously synonymous with Tarchia kielanae , now designated as nomen dubium . [twenty] | ||||
Homalocephale | Homalocephale calathoceros | Pachycephalosaurids. | ||||
Prenocephale | P. prenes | "A whole skull with a bound skeleton." [21] | Pachycephalosaurids . | |||
Saichania | Saichania chulsanensis | "The whole skull." | Ankylosaurus, also found in the Baruun Goyot formation. | |||
Saaurolophus | Saaurolophus angustirostris | “At least [fifteen] specimens, including an articulated skull and skeleton.” [19] | Hadrosauride. | |||
Tarchia | Tarchia teresae [22] | Ankylosaurus. | ||||
Sauropods
| Zauropods from the Namagat Formation | ||||||
|---|---|---|---|---|---|---|
| Kind | View | Location | Stratigraphic position | Material | Notes | Pictures |
Nemegtosaurus | Nemegtosaurus mongoliensis | "Skull." [23] | Titanosaurus | Nemegtosaurus | ||
Opisthocoelicaudia | Opisthocoelicaudia skarzynskii | "Skeleton without a skull and cervical vertebrae." [24] | Titanosaurus | |||
Fossil Eggs
| Fossil Eggs from Namagat Formation | ||||||
|---|---|---|---|---|---|---|
| Garden | Oowid | Location | Stratigraphic position | Material | Notes | Pictures |
Laevisoolithus [25] | Laevisoolithus sochavai | “A whole egg with a crack” [25] | Postponed by a bird or small theropod. [25] | |||
Subtiliolithus [25] | Subtiliolithus microtuberculatus [25] | "Shell fragments" [25] | ||||
See also
- Baruun Goyot
- Namegat (hollow)
- Namagat (river)
- Hahteeg
- Ural-Mongolian folded belt
Notes
- ↑ Michael Novachek. Dinosaurs of the Flaming Cliff. - 1997.
- ↑ Mark Norell, Eugene S. Gaffney, Lowell Dingus. Discovering Dinosaurs: Evolution, Extinction, and the Lessons of Prehistory. - 2000 .-- S. 153.
- ↑ Novacek, M. (1996). Dinosaurs of the Flaming Cliffs. Bantam Doubleday Dell Publishing Group Inc. New York, New York. ISBN 978-0-385-47775-8
- ↑ 1 2 3 4 5 "Table 8.1," in Weishampel, et al. (2004). Page 167.
- ↑ 1 2 "Table 8.1," in Weishampel, et al. (2004). Page 166.
- ↑ 1 2 3 4 5 6 7 8 9 10 11 12 13 Barsbold, R. (1983). "Carnivorous dinosaurs from the Cretaceous of Mongolia [in Russian]." Trudy, Sovmestnaâ Sovetsko − Mongol'skaâ paleontologičeskaâ èkspediciâ , 19 : 1–120.
- ↑ "Table 10.1," in Weishampel, et al. (2004). Page 198.
- ↑ 1 2 3 "Table 9.1," in Weishampel, et al. (2004). Page 185.
- ↑ "Table 11.1," in Weishampel, et al. (2004). Page 213.
- ↑ "Table 11.1," in Weishampel, et al. (2004). Page 215.
- ↑ Norell, MA; Makovicky, PJ; Bever, GS; Balanoff, AM; Clark, JM; Barsbold, R .; Rowe, T. A Review of the Mongolian Cretaceous Dinosaur Saurornithoides (Troodontidae: Theropoda) (English) // American Museum Novitates : journal. - American Museum of Natural History , 2009. - Vol. 3654 . - P. 63 . - DOI : 10.1206 / 648.1 .
- ↑ 1 2 3 "Table 6.1," in Weishampel, et al. (2004). Page 138.
- ↑ "Table 5.1," in Weishampel, et al. (2004). Page 112.
- ↑ DVIDS - Images - The "Gallimimus slab" [Image 9 of 9]
- ↑ 1 2 Michael G. Newbrey, Donald B. Brinkman, Dale A. Winkler, Elizabeth A. Freedman, Andrew G. Neuman, Denver W. Fowler and Holly N. Woodward. Teleost centrum and jaw elements from the Upper Cretaceous Nemegt Formation (Campanian-Maastrichtian) of Mongolia and a re-identification of the fish centrum found with the theropod Raptorex kreigsteini // Mesozoic Fishes 5 - Global Diversity and Evolution. - Verlag Dr. Friedrich Pfeil, 2013 .-- P. 291-303. - ISBN 978-3-89937-159-8 .
- ↑ Fowler DW, Woodward HN, Freedman EA, Larson PL, Horner JR (2011) Reanalysis of “Raptorex kriegsteini”: A Juvenile Tyrannosaurid Dinosaur from Mongolia . PLoS ONE 6 (6): e21376. DOI : 10.1371 / journal.pone.0021376
- ↑ DVIDS - Images - Skull of Tarbosaurus baatar [Image 7 of 9]
- ↑ "Table 7.1," in Weishampel, et al. (2004). Page 152.
- ↑ 1 2 "Table 20.1," in Weishampel, et al. (2004). Page 441.
- ↑ Arbor, VM, Currie, PJ and Badamgarav, D. (2014), The ankylosaurid dinosaurs of the Upper Cretaceous Baruungoyot and Nemegt formations of Mongolia. Zoological Journal of the Linnean Society, 172: 631–652. doi: 10.1111 / zoj.12185
- ↑ "Table 21.1," in Weishampel, et al. (2004). Page 465.
- ↑ Paul Penkalski; Tatiana Tumanova (2016). "The cranial morphology and taxonomic status of Tarchia (Dinosauria: Ankylosauridae) from the Upper Cretaceous of Mongolia." Cretaceous Research. in press. doi: 10.1016 / j.cretres.2016.10.00.004.
- ↑ "Table 13.1," in Weishampel, et al. (2004). Page 263.
- ↑ "Table 13.1," in Weishampel, et al. (2004). Page 270.
- ↑ 1 2 3 4 5 6 KE Mikhailov. 1991. Classification of fossil eggshells of amniotic vertebrates. Acta Palaeontologica Polonica 36 (2): 193-238