''Khulsanurus'' (meaning "tail from Khulsan") is an extinct genus of

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 ...

theropod Theropoda (; ), whose members are known as theropods, is a dinosaur clade that is characterized by hollow bones and three toes and claws on each limb. Theropods are generally classed as a group of saurischian dinosaurs. They were ancestrally c ...

dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the evolution of dinosaurs is t ...

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 ...

Barungoyot Formation of the Khulsan Locality in the

Gobi Desert The Gobi Desert (Chinese: 戈壁 (沙漠), Mongolian: Говь (ᠭᠣᠪᠢ)) () is a large desert or brushland region in East Asia, and is the sixth largest desert in the world. Geography The Gobi measures from southwest to northeast an ...

region of

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 type and only species is ''Khulsanurus magnificus''.

Description

''Khulsanurus'' is known from a

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 ...

containing partial vertebral series of the neck and tail, scapulocoracoids, a right humerus, a possible left humerus, and a left pubis. Distinguishing autapomorphies of this specimen include pleurocoel-, carotid process-, and epipophysis-less cervical vertebrae, prominent infrapostzygapophyseal fossa of the caudal vertebrae which also bear anteriorly pointing prezygapophyses.

Classification

Averianov & Lopatin (2021) placed ''Khulsanurus'' in a

polytomy An internal node of a phylogenetic tree is described as a polytomy or multifurcation if (i) it is in a rooted tree and is linked to three or more child subtrees or (ii) it is in an unrooted tree and is attached to four or more branches. A tr ...

with ''

Albinykus ''Albinykus'' (meaning " Albin claw", after a term used by Mongolian shamans to describe light phenomena in the Gobi Desert) is a genus of alvarezsaurid dinosaur. Fossils have been found from Late Cretaceous-age (Santonian) Javkhlant Formation in ...

'', ''

Ceratonykus ''Ceratonykus'' (meaning "horned claw") is a monospecific genus of alvarezsaurid dinosaur from Mongolia that lived during the Late Cretaceous (late Campanian stage, 72.1 Ma) in what is now the Barun Goyot Formation. The type and only species, ''C ...

'', ''

Linhenykus ''Linhenykus'' is an extinct genus of alvarezsaurid theropod dinosaur from the Late Cretaceous of Inner Mongolia, China. It is the most basal known member of the Parvicursorinae. The genus gets its name from Linhe, a city near the site where th ...

'', ''

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 ...

'', ''

Xixianykus ''Xixianykus'' is a genus of alvarezsaurid theropod dinosaur from the late Cretaceous period of China.Xu, X., Wang, D.Y., Sullivan, C., Hone, D.W.E., Han, F.L., Yan, R.H. and Du, F.M. (2010). "A basal parvicursorine (Theropoda: Alvarezsauridae) ...

'', ''

Qiupanykus ''Qiupanykus'' (meaning "Qiupa claw" after the Qiupa Formation) is a genus of alvarezsaurid coelurosaur theropod from the Late Cretaceous Qiupa Formation of southern China. Fossil eggs believed to be those of an oviraptorid found in association ...

'', ''

Nemegtonykus ''Nemegtonykus'' (meaning "Nemegt claw" after the Nemegt Formation where it was found) is a genus of alvarezsaurid dinosaur from the Nemegt Formation in Mongolia. The type and only species is ''Nemegtonykus citus''. It is the second alvarezsaur ...

'', PIN 5838/1 (=''

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 a clade containing ''

Shuvuuia ''Shuvuuia'' is a genus of bird-like theropod dinosaur from the late Cretaceous period of Mongolia. It is a member of the family Alvarezsauridae, small coelurosaurian dinosaurs which are characterized by short but powerful forelimbs specialized f ...

'' and ''

Mononykus ''Mononykus'' ( , sometimes ; meaning "one claw") is a genus of alvarezsaurid dinosaur that lived during the Late Cretaceous in what is now Asia on the Nemegt Formation, about 70 million years ago. ''Mononykus'' was a very small theropod, estim ...

'' in a strict consensus tree using unweighted characters. However, Averianov & Lopatin (2021) also recovered it in a polytomy with only ''Albinykus'', ''Xixianykus'', PIN 5838/1 (=''Ondogurvel''), ''Mononykus'' and ''Shuvuuia'' in a consensus tree using implied weighting. Averianov & Sues (2022) conducted a phylogenetic analysis using implied weighting which recovered it in a similar position but with inclusion of a clade containing ''Linhenykus'', ''Ceratonykus'' and ''Parvicuror'' and the exclusion of ''Qiupanykus'' and ''Nemegtonykus'', while a 50% majority rule tree from the same analysis placed it within a polytomy with two clades. A phylogenetic analysis conducted by Averianov & Sues (2022) is reproduced below.

Paleoenvironment

''Khulsanurus'' was found in the Campanian

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 ...

, which was also home to many other animals, including mammals such as ''

Catopsbaatar ''Catopsbaatar'' is a genus of multituberculate, an extinct order of rodent-like mammals. It lived in what is now Mongolia during the late Campanian age of the Late Cretaceous epoch, about 72 million years ago. The first fossils were colle ...

'' and ''

Nemegtbaatar ''Nemegtbaatar'' is a genus of mammal from the Upper Cretaceous Period of what is now Mongolia. It existed in the company of much larger dinosaurs, found together in the Nemegt Basin. This creature was a member of the extinct order Multituber ...

'', squamates such as ''

Estesia ''Estesia'' (in honour of Richard Estes) is an extinct genus of Late Cretaceous anguimorph lizard found in the Gobi Desert in Mongolia. It was discovered in June 1990 by a joint expedition made up of Mongolian and American palaeontologists, and d ...

'', ''

Gobiderma ''Gobiderma'' is an extinct genus of Late Cretaceous lizard whose fossils are known from the Gobi Desert in southern Mongolia Mongolia; Mongolian script: , , ; lit. "Mongol Nation" or "State of Mongolia" () is a landlocked country i ...

'', and ''

Proplatynotia ''Proplatynotia'' is an extinct genus of varanoid lizard from the Late Cretaceous of Mongolia. Fossils have been found in the Barun Goyot Formation, which is mid-Campanian in age. The type and only species, ''P. longirostratia'', was named in ...

'', and numerous dinosaurs, including ornithischians such as ''

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 ...

'', ''

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. ...

'', ''

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 ...

'', ''

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 ...

'', ''

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 ...

'', ''

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 ...

'', and ''

Udanoceratops ''Udanoceratops'' (meaning "Udan's horned face") is a genus of large leptoceratopsid dinosaur that lived during the Late Cretaceous period of Mongolia, in what is now the Djadokhta Formation. Discovery ''Udanoceratops'' was first named and d ...

''; sauropods such as '' Quaesitosaurus'';Kurzanov, S. and Bannikov, A. (1983). "A new sauropod from the Upper Cretaceous of Mongolia". ''Paleontologicheskii Zhurnal'' 2: 90–96. and theropods, including ''

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 ...

'', ''

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 ...

'', ''

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 ...

'', ''

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, ...

'', ''

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, ...

'', ''

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''.

References

{{Taxonbar, from=Q109642447 Alvarezsaurids Campanian genera Late Cretaceous dinosaurs of Asia Cretaceous Mongolia Fossils of Mongolia Barun Goyot Formation Fossil taxa described in 2021 Taxa named by Alexander O. Averianov