''Wulong'' (meaning "dancing dragon") is a genus of microraptorine

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 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 ...

s from the

Early Cretaceous The Early Cretaceous ( geochronological name) or the Lower Cretaceous (chronostratigraphic name), is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 145 Ma to 100.5 Ma. Geology Pro ...

(

Aptian The Aptian is an age in the geologic timescale or a stage in the stratigraphic column. It is a subdivision of the Early or Lower Cretaceous Epoch or Series and encompasses the time from 121.4 ± 1.0 Ma to 113.0 ± 1.0 Ma (million years ago), a ...

)

Jiufotang Formation The Jiufotang Formation ( Chinese: 九佛堂组, pinyin: ''jiǔfótáng zǔ'') is an Early Cretaceous geological formation in Chaoyang, Liaoning which has yielded fossils of feathered dinosaurs, primitive birds, pterosaurs, and other organisms (see ...

China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...

. It includes one species, ''Wulong bohaiensis''. The skeletal remains represent a juvenile.

Discovery

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 ...

specimen of the dinosaur, D2933, was found by a farmer in the fossil-rich

Liaoning Liaoning () is a coastal province in Northeast China that is the smallest, southernmost, and most populous province in the region. With its capital at Shenyang, it is located on the northern shore of the Yellow Sea, and is the northernmost ...

Province, China. Since then the fossil skeleton has been housed in the collection of the Dalian Natural History Museum in Liaoning. The skeletal bones were analyzed by Ashley William Poust who named them as ''Wulong bohaiensis'' in a thesis in 2014.A.W. Poust. 2014. ''Description and ontogenetic assessment of a new Jehol microraptorine''. M.Sc. Thesis, Montana State University, Bozeman, Montana This name for the time being remained an invalid ''nomen ex dissertatione''. In 2020, Poust alongside his former advisor David Varricchio from

Montana State University Montana State University (MSU) is a Public university, public land-grant university, land-grant research university in Bozeman, Montana. It is the state's largest university. MSU offers baccalaureate degrees in 60 fields, master's degrees in 6 ...

and

Dalian Dalian () is a major sub-provincial port city in Liaoning province, People's Republic of China, and is Liaoning's second largest city (after the provincial capital Shenyang) and the third-most populous city of Northeast China. Located on the ...

paleontologists Gao Chunling, Wu Jianlin, and Zhang Fengjiao validly 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 ...

''Wulong bohaiensis''. The generic name is derived from Chinese 舞, ''wǔ'', "dancing", in reference to the "individual's sprightly pose and inferred nimble habits", and 龍/龙, ''lóng'', "dragon". The specific name refers to the museum being located at the

Bohai Strait The Bohai Sea () is a marginal sea approximately in area on the east coast of Mainland China. It is the northwestern and innermost extension of the Yellow Sea, to which it connects to the east via the Bohai Strait. It has a mean depth o ...

(渤海 or Bó Hǎi).

Description

The long and bony tail of ''Wulong bohaiensis'' is double its body length. Its skeleton had hollow bones. The specimen includes feathers on its limbs and two long plumes at the end of its tail. In addition, it has a narrow head that carries thin jaws filled with small and sharp teeth. It is closely related to ''

Sinornithosaurus ''Sinornithosaurus'' (derived from a combination of Latin and Greek, meaning 'Chinese bird-lizard') is a genus of feathered dromaeosaurid dinosaur from the early Cretaceous Period (late Barremian) of the Yixian Formation in what is now China. ...

'' from the

Yixian Formation The Yixian Formation (; formerly transcribed as Yihsien Formation) is a geological formation in Jinzhou, Liaoning, People's Republic of China, that spans the late Barremian and early Aptian stages of the Early Cretaceous. It is known for its ex ...

. The long skull of ''Wulong'' is large in relation to the body. It is in 1.15 times the length of the

femur The femur (; ), or thigh bone, is the proximal bone of the hindlimb in tetrapod vertebrates. The head of the femur articulates with the acetabulum in the pelvic bone forming the hip joint, while the distal part of the femur articulates with ...

. The lighty built

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 ...

, one of a pair of small

cranial bones In human anatomy, the neurocranium, also known as the braincase, brainpan, or brain-pan is the upper and back part of the skull, which forms a protective case around the brain. In the human skull, the neurocranium includes the calvaria (skull), ...

at the very tip of the upper

jaw The jaw is any opposable articulated structure at the entrance of the mouth, typically used for grasping and manipulating food. The term ''jaws'' is also broadly applied to the whole of the structures constituting the vault of the mouth and serv ...

, is relatively short dorsoventrally for a dromaeosaurid. The

quadratojugal The quadratojugal is a skull bone present in many vertebrates, including some living reptiles and amphibians. Anatomy and function In animals with a quadratojugal bone, it is typically found connected to the jugal (cheek) bone from the front and ...

of most dromaeosaurids is T-shaped, but in ''Wulong'' this bone is tiny and L‐shaped. The ascending process of this theropod is about 6 mm tall, the jugal process is 5 mm long.

References

Microraptorians Early Cretaceous dinosaurs of Asia Cretaceous China Fossil taxa described in 2020 Jiufotang fauna {{theropod-stub