Natovenator Temporal range: Maastrichtian, | |
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Skeletal reconstruction, based on the holotype | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Clade: | Dinosauria |
Clade: | Saurischia |
Clade: | Theropoda |
Family: | † Dromaeosauridae |
Subfamily: | † Halszkaraptorinae |
Genus: | † Natovenator Lee et al., 2022 |
Species: | †N. polydontus |
Binomial name | |
†Natovenator polydontus Lee et al., 2022 | |
Natovenator is a genus of halszkaraptorine dromaeosaurid dinosaur from the Late Cretaceous Barun Goyot Formation of Mongolia. The genus is known from a single species, N. polydontus. Natovenator is crucial to the understanding of halszkaraptorines due to it providing more support for the semi-aquatic lifestyle that has been proposed for this clade. [1] This discovery is important as the semi-aquatic lifestyles of halszkaraptorines (mainly Halszkaraptor ) was contested in early 2022. [2]
The Natovenator holotype specimen, MPC-D 102/114, was found in sediments of the Barun Goyot Formation of Omnogovi Province, Mongolia. It consists of a mostly articulated skeleton with a nearly complete skull. [1]
The specimen was first mentioned in a 2019 abstract. [3] In 2022, Natovenator polydontus was described as a new genus and species of halszkaraptorine theropod dinosaurs by Sungjin Lee, Yuong-Nam Lee, Philip J. Currie, Robin Sissons, Jin-Young Park, Su-Hwan Kim, Rinchen Barsbold, and Khishigjav Tsogtbaatar based on these remains. The generic name, "Natovenator", is derived from the Latin words "nato", meaning "to swim", and "venator", meaning "hunter", in reference to its piscivorous diet and possible swimming behaviour. The specific name, "polydontus", is derived from the Greek words "polys", meaning "many", and "odous", meaning "tooth". [1]
Natovenator was a very small theropod, comparable in appearance to extant waterfowl, like other members of the Halszkaraptorinae. In the third edition of The Princeton Field Guide to Dinosaurs, Gregory S. Paul stated its length at 0.7 metres (2.3 ft) and weight at 0.3 kilograms (0.66 lb). [4] Natovenator is different from other halszkaraptorines due to features such as a wide groove delimited by a pair of ridges on the anterodorsal surface of the premaxilla, a premaxilla with an elongated internarial process that overlies nasal and extends posterior to the external naris, 13 premaxillary teeth with large and incisiviform crowns, the absence of pleurocoels in cervical vertebrae, and an hourglass-shaped metacarpal II, among other features. The parapophyses in its vertebrae are similar to the extinct Hesperornithiformes, which were toothed diving birds. [1]
In their phylogenetic analyses, Lee et al. (2022) recovered Natovenator as a derived member of the Halszkaraptorinae, with Halszkaraptor being the most basal member of the group. The cladogram below displays the results of their phylogenetic analyses. [1]
In 2022, Lee and colleagues regarded Natovenator as an efficient swimming dromaeosaurid with a semiaquatic lifestyle. The multiple convergences with other aquatic vertebrates include an elongated snout with numerous teeth, delayed replacement pattern of premaxillary teeth, a complex neurovascular system on the snout tip, elongated neck and vertebral zygapophyses, and a retracted, long naris (nostril opening). The team indicated that the delayed pattern of the premaxillary dentition could have allowed it to keep providing enlarged teeth in Natovenator, in a similar way to sauropterygians. Similar to many modern-day diving birds, the neck of Natovenator was rather long, likely useful in catching/snatching prey. Most notably, its dorsal rib cage had posteriorly-oriented ribs, providing a streamlined shape that is also known in efficient diving birds, mosasaurs, choristoderes, and spinosaurids. Even though the exact aquatic locomotion of Natovenator is unknown, Lee and colleagues suggested that its forelimbs acted as flippers for propulsion when swimming. [1]
The Barun Goyot Formation is regarded as Late Cretaceous in age (Upper Campanian) based on sediments and fossil content. This formation is mostly characterized by red beds, mostly light-coloured sands (yellowish, grey-brown, and to a lesser extent reddish) that are well-cemented. Sandy claystones (often red-coloured), siltstones, conglomerates, and large-scale trough cross-stratification in sands are also common across the unit. In addition, structureless, medium-grained, fine-grained and very fine-grained sandstones predominate in sediments of the Barun Goyot Formation. Overall geology of the formation indicates that sediments were deposited under relatively arid to semiarid climates in alluvial plain (flat land consisting of sediments deposited by highland rivers), lacustrine, and aeolian paleoenvironments, with addition of other short-lived water bodies. [5] [6] [7]
The Barun Goyot Formation was also home to many other vertebrates, including the ankylosaurids Saichania , Tarchia and Zaraapelta ; [8] [9] alvarezsaurids Khulsanurus , Ondogurvel , and Parvicursor ; [10] [11] birds Gobipipus , Gobipteryx and Hollanda ; [12] dromaeosaurids Kuru and Shri ; [13] [14] fellow halszkaraptorine Hulsanpes ; [15] protoceratopsids Bagaceratops and Breviceratops ; [16] pachycephalosaurid Tylocephale ; [17] oviraptorids Conchoraptor , Heyuannia and Nemegtomaia ; [18] [19] and the large sauropod Quaesitosaurus . [20]
Anserimimus is a genus of ornithomimid theropod dinosaur, from the Late Cretaceous Period of what is now Mongolia. It was a lanky, fast-running animal, possibly an omnivore. From what fossils are known, it probably closely resembled other ornithomimids, except for its more powerful forelimbs.
Avimimus, meaning "bird mimic", is a genus of oviraptorosaurian theropod dinosaur, named for its bird-like characteristics, that lived in the late Cretaceous in what is now Mongolia, around 85 to 70 million years ago.
Adasaurus is a genus of dromaeosaurid dinosaur that lived in Asia during the Late Cretaceous period about 70 million years ago. The genus is known from two partial specimens found in the Nemegt Formation of Mongolia that were partially described in 1983 by the paleontologist Rinchen Barsbold.
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.
The Bayan Shireh Formation is a geological formation in Mongolia, that dates to the Cretaceous period. It was first described and established by Vasiliev et al. 1959.
Tylocephale is a genus of pachycephalosaurid dinosaur, a group of dome-headed, herbivorous ornithischians, that lived during the Late Campanian stage of the Late Cretaceous in what is now Mongolia. It is known from a partial skull and associated mandible that were unearthed in 1971 by a Polish-Mongolian Expedition to the Barun Goyot Formation of the Gobi Desert. The specimen was described in 1974 by Polish paleontologists Teresa Maryańska and Halszka Osmólska as a new genus and species.
Kuru is a genus of dromaeosaurid theropod from the Late Cretaceous Barun Goyot Formation of Mongolia. The genus contains only a single species, the type species Kuru kulla, which is known from a fragmentary skeleton including a partial skull.
Hulsanpes is a genus of halszkaraptorine theropod dinosaurs that lived during the Late Cretaceous in what is now the Barun Goyot Formation of Mongolia, about 75-72 million years ago. The remains were found in 1970 and formally described in 1982 by Halszka Osmólska, who noted that the genus is represented by an immature individual. Hulsanpes represents the first record of the basal dromaeosaurid subfamily Halszkaraptorinae.
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 Nemegt Formation is a geological formation in the Gobi Desert of Mongolia, dating to the Late Cretaceous. The formation consists of river channel sediments and contains fossils of fish, turtles, crocodilians, and a diverse fauna of dinosaurs, including birds.
The Djadochta formation is a highly fossiliferous geological formation 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.
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.
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.
Ceratonykus is a monospecific genus of alvarezsaurid dinosaur from Mongolia that lived during the Late Cretaceous in what is now the Barun Goyot Formation. The type and only species, Ceratonykus oculatus, is known from a fragmentary skeleton, including an incomplete skull, of an adult individual. It was named and described in 2009 by Vladimir Alifanov and Rinchen Barsbold. Its describers questioned the traditional placement of alvarezsaurs in Theropoda, instead suggesting they were ornithischians, but this has not been accepted since. Ceratonykus has an estimated length of 75 centimetres and weight of 760 grams. It has been considered as a possible junior synonym of Parvicursor.
Halszkaraptorinae is an extinct basal ("primitive") subfamily of Dromaeosauridae that includes the enigmatic genera Halszkaraptor, Natovenator, Mahakala, and Hulsanpes. Halszkaraptorines are definitively known only from Late Cretaceous strata in Asia, specifically in Mongolia. It is debated among researchers whether the group had a semiaquatic lifestyle.
Oksoko is a genus of oviraptorid dinosaur from the Late Cretaceous of Asia, that lived in what is now the Nemegt Formation in Mongolia. It includes the type species Oksoko avarsan.
Khulsanurus is an extinct genus of alvarezsaurid theropod dinosaur from the Late Cretaceous Barungoyot Formation of the Khulsan Locality in the Gobi Desert region of Mongolia. The type and only species is Khulsanurus magnificus.
Ondogurvel is a genus of alvarezsaurid dinosaur from the Late Cretaceous (Campanian) Barun Goyot Formation in southern Mongolia. The type and only species is O. alifanovi, known from a partial skeleton consisting of fragments of two last dorsal vertebrae, three anterior sacral vertebrae, right ilium, left and right pubis and ischium, articulated right tibia, fibula, metatarsals II and IV, and phalanges IV-1 and IV-2, right carpometacarpus, left and right manual phalanx II-1, right femur, left pedal phalanx II-1, and fragments of unidentified phalanges.
Jaculinykus is an extinct genus of alvarezsaurid theropod dinosaur from the Late Cretaceous Baruungoyot Formation of Mongolia. The genus contains a single species, J. yaruui, known from a nearly complete articulated skeleton including bones of the skull. Jaculinykus is notable for its unique hand, which has a hypertrophied first digit and greatly reduced second digit, which is intermediate between the tridactyl hand of Shuvuuia and monodactyl hand of Linhenykus.
Harenadraco is an extinct genus of troodontid theropod dinosaurs from the Late Cretaceous Baruungoyot Formation of Mongolia. The genus contains a single species, H. prima, known from a fragmentary skeleton. Harenadraco represents the first troodontid known from the Baruungoyot Formation. Since members of this family are also known from the Nemegt and Djadochta Formations, the discovery of Harendraco indicates that troodontids were important faunal components of every formation within the Nemegt Basin.