''Huanansaurus'' is an

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

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 ...

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 ...

that lived approximately 72

million years ago The abbreviation Myr, "million years", is a unit of a quantity of (i.e. ) years, or 31.556926 teraseconds. Usage Myr (million years) is in common use in fields such as Earth science and cosmology. Myr is also used with Mya (million years ago). ...

, between the

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 ...

and

Maastrichtian The Maastrichtian () is, in the ICS geologic timescale, the latest age (uppermost stage) of the Late Cretaceous Epoch or Upper Cretaceous Series, the Cretaceous Period or System, and of the Mesozoic Era or Erathem. It spanned the interval from ...

, during the latter part of the

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of th ...

period in what is now China, in the

Nanxiong Formation The Nanxiong Formation (also known as Yuanpu Formation) is a Late Cretaceous geologic formation in Guangdong Province. Dinosaur remains are among the fossils that have been recovered from the formation. Description It consists of continental s ...

Discovery and designation

The skeleton of a new oviraptorid ''Huanansaurus ganzhouensis'' was uncovered during the construction of the

Ganzhou Ganzhou (), alternately romanized as Kanchow, is a prefecture-level city in the south of Jiangxi province, China, bordering Fujian to the east, Guangdong to the south, and Hunan to the west. Its administrative seat is at Zhanggong District. Hist ...

railway station in

Jiangxi Jiangxi (; ; formerly romanized as Kiangsi or Chianghsi) is a landlocked province in the east of the People's Republic of China. Its major cities include Nanchang and Jiujiang. Spanning from the banks of the Yangtze river in the north int ...

province, China. Huanansaurus ganzhouensis holotype (HGM41HIII-0443)

In 2015,

Lü Junchang Lü Junchang (; 1965 – 9 October 2018) was a Chinese palaeontologist and professor at the Institute of Geology, Chinese Academy of Geological Sciences. An expert on Mesozoic reptiles, he described and named dozens of dinosaur and pterosaur taxa ...

, Pu Hanyong, Yoshitsugu Kobayashi, Xu Li, Chang Huali, Shang Yuhua, Liu Di, Lee Yuong-Nam, Martin Kundrát and Shen Caizhi named and described the

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen ...

''Huanansaurus ganzhouensis''. The generic name is derived from Huanan, "Southern China". The specific name refers to the provenance from Ganzhou. ''Huanansaurus'' was one of eighteen dinosaur taxa from 2015 to be described in open access or free-to-read journals. The

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 ...

, HGM41HIII-0443, was found in a layer of the Nanxiong Formation dating from the Campanian - Maastrichtian. It consists of a partially articulated, incomplete skeleton which includes a nearly complete skull and lower jaws, the first seven neck vertebrae, a humerus, ulna, radius and hand of the right arm, the left hand, the lower part of the right thighbone, the upper part of the right shinbone, and the distal parts of the right foot. The specimen is part of the collection of the

Henan Geological Museum The Henan Museum (), located in Zhengzhou, Henan Province, China, is a history and archaeology museum. It has a collection of more than 130,000 pieces of cultural relics through the ages. In addition to its collection of human history the museum ...

Zhengzhou Zhengzhou (; ), also spelt Zheng Zhou and alternatively romanized as Chengchow, is the capital and largest city of Henan Province in the central part of the People's Republic of China. Located in north-central Henan, it is one of the National ...

Description

Some unique traits of ''Huanansaurus'' have been established. Several of these are

autapomorphies In phylogenetics, an autapomorphy is a distinctive feature, known as a derived trait, that is unique to a given taxon. That is, it is found only in one taxon, but not found in any others or outgroup taxa, not even those most closely related to t ...

. Of the

quadrate bone The quadrate bone is a skull bone in most tetrapods, including amphibians, sauropsids (reptiles, birds), and early synapsids. In most tetrapods, the quadrate bone connects to the quadratojugal and squamosal bones in the skull, and forms upper ...

the lower condyles are positioned behind the upper head. The transverse nuchal crest on the rear skull roof is not very prominent. In the lower jaw the

angular bone The angular is a large bone in the lower jaw (mandible) of amphibians and reptiles (birds included), which is connected to all other lower jaw bones: the dentary (which is the entire lower jaw in mammals), the splenial, the suprangular, and the art ...

forms a major part of the lower rim of the outer side opening. The front point of the lower jaw is obliquely protruding to above under an angle of less than 45° with the symphysis, the fused point of the lower jaws. The shelf formed by the symphysis is moderately large, equal to about a fifth to a fourth of the total jaw length. The

dentary bone In anatomy, the mandible, lower jaw or jawbone is the largest, strongest and lowest bone in the human facial skeleton. It forms the lower jaw and holds the lower teeth in place. The mandible sits beneath the maxilla. It is the only movable bone ...

is pneumatised. The lower rear branch of the dentary is twisted, causing its outer side to be somewhat directed to below. The first metacarpal is long and slender with its transverse width equal to a fifth of its length. The hand claws have prominent lips on their upper rears. In addition, a unique combination of in themselves not unique traits is present. The temporal opening on the skull roof is round and much smaller than the temporal opening of the skull side. The rear branch of the

praemaxilla 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 ...

touches the

lacrimal bone The lacrimal bone is a small and fragile bone of the facial skeleton; it is roughly the size of the little fingernail. It is situated at the front part of the medial wall of the orbit. It has two surfaces and four borders. Several bony landmarks of ...

and features a prominent opening at this point, on the rear underside. The upper rear branch of the dentary covers the outer side opening of the lower jaw and has a concave lower rim. ''Huanansaurus'' was, within the

Oviraptoridae 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 ...

, placed in the

Oviraptorinae 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 on ...

, as a

sister species In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and t ...

of ''

Citipati ''Citipati'' (; meaning "funeral pyre lord") is a genus of oviraptorid dinosaur that lived in Asia during the Late Cretaceous period, about 75 million to 71 million years ago. It is mainly known from the Ukhaa Tolgod locality at the Djadokhta F ...

''. Below is a cladogram of

based on the

phylogenetic analysis 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 ...

of Lü ''et al.'' (2017).

References

{{Taxonbar, from=Q20640526 Late Cretaceous dinosaurs of Asia Oviraptorids Fossil taxa described in 2015 Paleontology in Jiangxi Taxa named by Lü Junchang Ganzhou

Discovery and designation

Description

See also

References