''Natovenator'' is a genus of

halszkaraptorine Halszkaraptorinae is a basal ("primitive") subfamily of Dromaeosauridae (or possibly Unenlagiidae) that includes the enigmatic genera ''Halszkaraptor'', ''Natovenator'', ''Mahakala'', and ''Hulsanpes''. Halszkaraptorines are definitively known o ...

dromaeosaurid Dromaeosauridae () is a family of feathered theropod dinosaurs. They were generally small to medium-sized feathered carnivores that flourished in the Cretaceous Period. The name Dromaeosauridae means 'running lizards', from Greek ('), meaning ...

dinosaur from the

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', the ...

Barun Goyot Formation The Barun Goyot Formation (also known as Baruungoyot Formation or West 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 Pro ...

Mongolia Mongolia; Mongolian script: , , ; lit. "Mongol Nation" or "State of Mongolia" () is a landlocked country in East Asia, bordered by Russia to the north and China to the south. It covers an area of , with a population of just 3.3 million, ...

. 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. This discovery is important as the semi-aquatic lifestyles of halszkaraptorines (mainly ''

Halszkaraptor ''Halszkaraptor'' (; meaning " Halszka's seizer") is a genus of waterfowl-like dromaeosaurid dinosaurs from Mongolia that lived during the Late Cretaceous period. It contains only one known species, ''Halszkaraptor escuilliei''. The type speci ...

'') was contested in early 2022.

Discovery and naming

The ''Natovenator''

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several ...

specimen, MPC-D 102/114, was found in sediments of the

of Omnogovi Province,

. It consists of a mostly articulated skeleton with a nearly complete skull. 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 Philip John Currie (born March 13, 1949) is a Canadian palaeontologist and museum curator who helped found the Royal Tyrrell Museum of Palaeontology in Drumheller, Alberta and is now a professor at the University of Alberta in Edmonton. In the ...

, Robin Sissons, Jin-Young Park, Su-Hwan Kim,

Rinchen Barsbold , Rinchyengiin Barsbold, born December 21, 1935 in Ulaanbaatar) is a Mongolian paleontologist and geologist. He works with the Institute of Geology, at Ulaanbaatar, Mongolia. He is an expert in vertebrate paleontology and Mesozoic stratigraphy. Bar ...

, and Khishigjav Tsogtbaatar based on these remains. The generic name, "''Natovenator''", is derived from the

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...

words "nato", meaning "to swim", and "venator", meaning "hunter", in reference to its

piscivorous A piscivore () is a carnivorous animal that eats primarily fish. The name ''piscivore'' is derived . Piscivore is equivalent to the Greek-derived word ichthyophage, both of which mean "fish eater". Fish were the diet of early tetrapod evoluti ...

diet and possible swimming behaviour. The

specific name Specific name may refer to: * in Database management systems, a system-assigned name that is unique within a particular database In taxonomy, either of these two meanings, each with its own set of rules: * Specific name (botany), the two-part (bino ...

, "''polydontus''", is derived from the

Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

words "polys", meaning "many", and "odous", meaning "tooth".

Description

''Natovenator'' was a very small theropod, comparable in appearance to extant

waterfowl Anseriformes is an order of birds also known as waterfowl that comprises about 180 living species of birds in three families: Anhimidae (three species of screamers), Anseranatidae (the magpie goose), and Anatidae, the largest family, which in ...

, like other members of the Halszkaraptorinae. ''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 The premaxilla (or praemaxilla) is one of a pair of small cranial bones at the very tip of the upper jaw of many animals, usually, but not always, bearing teeth. In humans, they are fused with the maxilla. The "premaxilla" of therian mammal has b ...

, 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 Hesperornithes is an extinct and highly specialized group of aquatic avialans closely related to the ancestors of modern birds. They inhabited both marine and freshwater habitats in the Northern Hemisphere, and include genera such as ''Hesperorni ...

, which were toothed diving birds.

Classification

In their

phylogenetic analyses In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...

, Lee ''et al''. (2022) recovered ''Natovenator'' as a derived member of the

Halszkaraptorinae Halszkaraptorinae is a basal ("primitive") subfamily of Dromaeosauridae (or possibly Unenlagiidae) that includes the enigmatic genera ''Halszkaraptor'', ''Natovenator'', ''Mahakala'', and ''Hulsanpes''. Halszkaraptorines are definitively known o ...

, with ''Halszkaraptor'' being the most basal member of the group. The

cladogram A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to d ...

below displays the results of their phylogenetic analyses.

Paleobiology

Aquatic habits

In 2022, Lee and colleagues regarded ''Natovenator'' as an efficient swimming dromaeosaurid with a

semiaquatic In biology, semiaquatic can refer to various types of animals that spend part of their time in water, or plants that naturally grow partially submerged in water. Examples are given below. Semiaquatic animals Semiaquatic animals include: * Verte ...

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

sauropterygia Sauropterygia ("lizard flippers") is an extinct taxon of diverse, aquatic reptiles that developed from terrestrial ancestors soon after the end-Permian extinction and flourished during the Triassic before all except for the Plesiosauria became ...

ns. Similar to many modern-day diving birds, the neck of ''Natovenator'' was rather long, likely useful in catching/snatching

prey Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill the ...

. Most notably, its dorsal

rib cage The rib cage, as an enclosure that comprises the ribs, vertebral column and sternum in the thorax of most vertebrates, protects vital organs such as the heart, lungs and great vessels. The sternum, together known as the thoracic cage, is a semi- ...

had posteriorly-oriented ribs, providing a streamlined shape that is also known in efficient diving birds,

mosasaurs Mosasaurs (from Latin ''Mosa'' meaning the 'Meuse', and Greek ' meaning 'lizard') comprise a group of extinct, large marine reptiles from the Late Cretaceous. Their first fossil remains were discovered in a limestone quarry at Maastricht on the ...

, choristoderes, and

spinosaurids The Spinosauridae (or spinosaurids) are a clade or Family (taxonomy), family of tetanuran theropod dinosaurs comprising ten to seventeen known genera. They came into prominence during the Cretaceous Geological period, period. Spinosaurid fossils h ...

. Even though the exact

aquatic locomotion Aquatic locomotion or swimming is biologically propelled motion through a liquid medium. The simplest propulsive systems are composed of cilia and flagella. Swimming has evolved a number of times in a range of organisms including arthropods, fi ...

of ''Natovenator'' is unknown, Lee and colleagues suggested that its forelimbs acted as flippers for propulsion when swimming.

Paleoenvironment

The

is regarded as

in age (Upper

Campanian The Campanian is the fifth of six ages of the Late Cretaceous Epoch on the geologic timescale of the International Commission on Stratigraphy (ICS). In chronostratigraphy, it is the fifth of six stages in the Upper Cretaceous Series. Campanian s ...

) based on

sediment Sediment is a naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of wind, water, or ice or by the force of gravity acting on the particles. For example, sand an ...

s and fossil content. This formation is mostly characterized by

red beds Red beds (or redbeds) are sedimentary rocks, typically consisting of sandstone, siltstone, and shale, that are predominantly red in color due to the presence of ferric oxides. Frequently, these red-colored sedimentary strata locally contain ...

, mostly light-coloured

sand Sand is a granular material composed of finely divided mineral particles. Sand has various compositions but is defined by its grain size. Sand grains are smaller than gravel and coarser than silt. Sand can also refer to a textural class of s ...

s (yellowish, grey-brown, and to a lesser extent reddish) that are well-cemented. Sandy

claystone Mudrocks are a class of fine-grained siliciclastic sedimentary rocks. The varying types of mudrocks include siltstone, claystone, mudstone, slate, and shale. Most of the particles of which the stone is composed are less than and are too sm ...

s (often red-coloured),

siltstone Siltstone, also known as aleurolite, is a clastic sedimentary rock that is composed mostly of silt. It is a form of mudrock with a low clay mineral content, which can be distinguished from shale by its lack of fissility.Blatt ''et al.'' 1980, p ...

s, conglomerates, and large-scale trough

cross-stratification In geology, cross-bedding, also known as cross-stratification, is layering within a stratum and at an angle to the main bedding plane. The sedimentary structures which result are roughly horizontal units composed of inclined layers. The original ...

in sands are also common across the unit. In addition, structureless, medium-grained, fine-grained and very fine-grained

sandstone Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks. Most sandstone is composed of quartz or feldspar (both silicates) ...

s predominate in sediments of the Barun Goyot Formation. Overall geology of the formation indicates that sediments were deposited under relatively

arid A region is arid when it severely lacks available water, to the extent of hindering or preventing the growth and development of plant and animal life. Regions with arid climates tend to lack vegetation and are called xeric or desertic. Most ar ...

semiarid climate A semi-arid climate, semi-desert climate, or steppe climate is a dry climate sub-type. It is located on regions that receive precipitation below potential evapotranspiration, but not as low as a desert climate. There are different kinds of semi-ar ...

s in

alluvial plain An alluvial plain is a largely flat landform created by the deposition of sediment over a long period of time by one or more rivers coming from highland regions, from which alluvial soil forms. A floodplain is part of the process, being the sma ...

(flat land consisting of sediments deposited by highland

river A river is a natural flowing watercourse, usually freshwater, flowing towards an ocean, sea, lake or another river. In some cases, a river flows into the ground and becomes dry at the end of its course without reaching another body of wate ...

s),

lacustrine A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much larger ...

, and aeolian paleoenvironments, with addition of other short-lived

water bodies A body of water or waterbody (often spelled water body) is any significant accumulation of water on the surface of Earth or another planet. The term most often refers to oceans, seas, and lakes, but it includes smaller pools of water such as p ...

. The Barun Goyot Formation was also home to many other

vertebrate Vertebrates () comprise all animal taxa within the subphylum Vertebrata () ( chordates with backbones), including all mammals, birds, reptiles, amphibians, and fish. Vertebrates represent the overwhelming majority of the phylum Chordata, ...

s, including the

ankylosaurid Ankylosauridae () is a family of armored dinosaurs within Ankylosauria, and is the sister group to Nodosauridae. The oldest known Ankylosaurids date to around 122 million years ago and went extinct 66 million years ago during the Cretaceous–Pal ...

s ''

Saichania ''Saichania'' (Mongolian meaning "beautiful one") is a genus of herbivorous ankylosaurid dinosaur from the Late Cretaceous period of Mongolia and China. The first fossils of ''Saichania'' were found in the early 1970s in Mongolia. In 1977 the ty ...

'', ''

Tarchia ''Tarchia'' (meaning "brainy one") is a genus of herbivorous ankylosauridae, ankylosaurid dinosaur from the late Cretaceous of Mongolia. Discovery and naming In 1970, a Polish-Mongolian expedition discovered an ankylosaurian skull near Khulsan. ...

'' and ''

Zaraapelta ''Zaraapelta'' is an extinct genus of herbivorous ankylosaurid thyreophoran dinosaur from the Late Cretaceous of Mongolia. The type species is ''Zaraapelta nomadis'', named and described by Arbour ''et al'' in 2014. ''Zaraapelta'' is known from ...

'';

alvarezsaurid Alvarezsauridae is a family of small, long-legged dinosaurs. Although originally thought to represent the earliest known flightless birds, they are now thought to be an early diverging branch of maniraptoran theropods. Alvarezsaurids were highly ...

s ''

Khulsanurus ''Khulsanurus'' (meaning "tail from Khulsan") 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 ''Khul ...

'', ''

Ondogurvel ''Ondogurvel'' () (meaning "egg lizard") 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 ...

'', and ''

Parvicursor ''Parvicursor'' (meaning "small runner") is a genus of tiny maniraptoran dinosaur with long slender legs for fast running. At only about from snout to end of tail, and in weight, it was initially seen as one of the smallest non-avian dinosaur ...

'';

bird Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweigh ...

s '' Gobipipus'', ''

Gobipteryx ''Gobipteryx'' (from Gobi eferring to the Gobi Desert where it was first discovered and Greek pteryx “wing”) is a genus of prehistoric bird from the Campanian Age (geology), Age of the Late Cretaceous Period (geology), Period.Elżanowski, ...

'' and '' Hollanda'';

s ''

Kuru Kuru may refer to: Anthropology and history * Kuru (disease), a type of transmissible spongiform encephalopathy associated with the cannibalistic funeral practices of the Fore people * Kuru (mythology), part of Meithei mythology * Kuru Kingdom, ...

'' and ''

Shri Shri (; , ) is a Sanskrit term denoting resplendence, wealth and prosperity, primarily used as an honorific. The word is widely used in South and Southeast Asian languages such as Marathi, Malay (including Indonesian and Malaysian), Javanese, ...

''; fellow

Hulsanpes ''Hulsanpes'' ( meaning " Khulsan foot") 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 ...

'';

protoceratopsid Protoceratopsidae is a family of basal (primitive) ceratopsians from the Late Cretaceous period. Although ceratopsians have been found all over the world, protoceratopsids are only definitively known from Cretaceous strata in Asia, with most spec ...

s ''

Bagaceratops ''Bagaceratops'' (meaning "small-horned face") 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 Forma ...

'' and ''

Breviceratops ''Breviceratops'' (meaning "short horned face") is a genus of protoceratopsid dinosaur that lived during the Late Cretaceous in what is now the Barun Goyot Formation, Mongolia. Discovery and naming The first fossils were discovered during the 1 ...

'';

pachycephalosaurid Pachycephalosauria (; from Greek παχυκεφαλόσαυρος for 'thick headed lizards') is a clade of ornithischian dinosaurs. Along with Ceratopsia, it makes up the clade Marginocephalia. With the exception of two species, most pachycephal ...

Tylocephale ''Tylocephale'' (meaning "swollen head", from the Greek ''τυλη'' meaning 'callus' or 'hard swelling' and ''κεφαλη'' meaning 'head') is a genus of pachycephalosaurid dinosaur from the Late Cretaceous period. It was a herbivorous dinosau ...

'';

oviraptorid Oviraptoridae is a group of bird-like, herbivorous and omnivorous maniraptoran dinosaurs. Oviraptorids are characterized by their toothless, parrot-like beaks and, in some cases, elaborate crests. They were generally small, measuring between one ...

s ''

Conchoraptor ''Conchoraptor'' (meaning "conch plunderer") is a genus of oviraptorid dinosaurs that lived in Asia during the Late Cretaceous epoch, about 70 million years ago. It is known from the Barun Goyot and Nemegt formations of Mongolia. Discovery When ...

'', ''

Heyuannia ''Heyuannia'' ("from Heyuan") is a genus of oviraptorid dinosaur that lived in Asia during the Late Cretaceous epoch, in what is now China and Mongolia. It was the first oviraptorid found in China; most others were found in neighbouring Mongolia ...

'' and ''

Nemegtomaia ''Nemegtomaia'' is a genus of oviraptorid dinosaur from what is now Mongolia that lived in the Late Cretaceous Period (geology), Period, about 70million years ago. The first specimen was found in 1996, and became the basis of the new genus and s ...

''; and the

large Large means of great size. Large may also refer to: Mathematics * Arbitrarily large, a phrase in mathematics * Large cardinal, a property of certain transfinite numbers * Large category, a category with a proper class of objects and morphisms (or ...

sauropod ''

Quaesitosaurus ''Quaesitosaurus'' (meaning "extraordinary lizard") is a genus of nemegtosaurid sauropod containing only the type species, ''Q. orientalis'', described in 1983. It lived from 72 to 71 million years ago during the Late Cretaceous epoch in the Barun ...

''.

References

External links

* * {{Taxonbar, from=Q115600849 Dromaeosaurs Maastrichtian life Late Cretaceous dinosaurs of Asia Cretaceous Mongolia Fossils of Mongolia Barun Goyot Formation Fossil taxa described in 2022

Discovery and naming

Description

Classification

Paleobiology

Aquatic habits

Paleoenvironment

See also

References

External links