''Phaedrolosaurus'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

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 ...

, based on a single

tooth A tooth ( : teeth) is a hard, calcified structure found in the jaws (or mouths) of many vertebrates and used to break down food. Some animals, particularly carnivores and omnivores, also use teeth to help with capturing or wounding prey, ...

possibly from the

Valanginian In the geologic timescale, the Valanginian is an age or stage of the Early or Lower Cretaceous. It spans between 139.8 ± 3.0 Ma and 132.9 ± 2.0 Ma (million years ago). The Valanginian Stage succeeds the Berriasian Stage of the Lower Cretace ...

Albian The Albian is both an age of the geologic timescale and a stage in the stratigraphic column. It is the youngest or uppermost subdivision of the Early/Lower Cretaceous Epoch/ Series. Its approximate time range is 113.0 ± 1.0 Ma to 100.5 ± 0 ...

-age

Lower Cretaceous Lower may refer to: * Lower (surname) * Lower Township, New Jersey *Lower Receiver (firearms) * Lower Wick Gloucestershire, England See also *Nizhny Nizhny (russian: Ни́жний; masculine), Nizhnyaya (; feminine), or Nizhneye (russian: Н� ...

Lianmugin Formation The Lianmuqin Formation, also transcribed as Lianmugin Formation,

of Wuerho,

Xinjiang Xinjiang, SASM/GNC: ''Xinjang''; zh, c=, p=Xīnjiāng; formerly romanized as Sinkiang (, ), officially the Xinjiang Uygur Autonomous Region (XUAR), is an autonomous region of the People's Republic of China (PRC), located in the northwes ...

China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's List of countries and dependencies by population, most populous country, with a Population of China, population exceeding 1.4 billion, slig ...

Discovery and naming

The first known remains of ''Phaedrolosaurus'' were discovered in China during an

Institute of Vertebrate Paleontology and Paleoanthropology The Institute of Vertebrate Paleontology and Paleoanthropology (IVPP; ) of China is a research institution and collections repository for fossils, including many dinosaur and pterosaur specimens (many from the Yixian Formation). As its name sugg ...

(IVPP) expedition to China's Wuerho area in 1964. The tooth, IVPP V , was in 1973 described and named by

Dong Zhiming Dong Zhiming (Chinese: 董枝明, Pinyin: ''Dǒng Zhimíng''; born January 1937) is a Chinese vertebrate paleontologist formerly employed at the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) in Beijing. He began working at th ...

as a new genus and species. 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 specim ...

is ''Phaedrolosaurus ilikensis''. The generic name is derived from the Greek φαιδρός, ''phaidros'', "elated", referring to the agility of the animal. The specific name refers to the

Ilike Formation iLike was an online service that allowed users to download and share music founded by brothers Ali Partovi and Hadi Partovi. The website made use of a sidebar that is used with Apple's iTunes or Microsoft's Windows Media Player. The program ...

. Dong stated the thirty-one millimetre long tooth was like those of ''

Deinonychus ''Deinonychus'' ( ; ) is a genus of dromaeosaurid theropod dinosaur with one described species, ''Deinonychus antirrhopus''. This species, which could grow up to long, lived during the early Cretaceous Period, about 115–108 million y ...

'', albeit thicker, shorter, and more solid. He regarded the new genus as a possible

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 ...

.Z.-M. Dong. (1973). inosaurs from Wuerho ''Memoirs of the Institute of Vertebrate Paleontology and Paleoanthropology, Academic Sinica'' 11:45-52. hinese/ref> As part of the type material of this genus Dong described several skeletal elements from other sites, among them a partial, articulated right

leg A leg is a weight-bearing and locomotive anatomical structure, usually having a columnar shape. During locomotion, legs function as "extensible struts". The combination of movements at all joints can be modeled as a single, linear element ca ...

. Because this latter limb material showed

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 ...

, distinctive characteristics, and there was no reason to connect it to the nondiagnostic tooth, Rauhut and Xu in 2005 gave this material its own name, '' Xinjiangovenator parvus''. They also recommended regarding ''Phaedrolosaurus'' as a ''

nomen dubium In binomial nomenclature, a ''nomen dubium'' (Latin for "doubtful name", plural ''nomina dubia'') is a scientific name that is of unknown or doubtful application. Zoology In case of a ''nomen dubium'' it may be impossible to determine whether a s ...

'', a dubious name.Rauhut, O.W.M., and Xu, X. (2005). The small theropod dinosaurs ''Tugulusaurus'' and ''Phaedrolosaurus'' from the Early Cretaceous of Xinjiang, China. ''Journal of Vertebrate Paleontology'' 25(1):107-118 Because Dong had not designated 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 seve ...

among the several specimens in 1973 assigned to ''Phaedrolosaurus'', in 1977

Hans-Dieter Sues Hans-Dieter Sues (born January 13, 1956) is a German-born American paleontologist who is Senior Scientist and Curator of Vertebrate Paleontology at the National Museum of Natural History of the Smithsonian Institution in Washington, DC. He receiv ...

had made the tooth the

lectotype In biology, a type is a particular specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally attached. In other words, a type is an example that serves to anchor or centralizes the ...

.Sues, H.-D., 1977, "The skull of ''Velociraptor mongoliensis'', a small Cretaceous theropod dinosaur from Mongolia", ''Paläontologische Zeitschrift'', 51: 173-184

References

{{Taxonbar, from=Q2649007 Prehistoric coelurosaurs Early Cretaceous dinosaurs of Asia Nomina dubia Taxa named by Dong Zhiming Fossil taxa described in 1973 Paleontology in Xinjiang