''Rapator'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

theropod Theropoda (; from ancient Greek , (''therion'') "wild beast"; , (''pous, podos'') "foot"">wiktionary:ποδός"> (''pous, podos'') "foot" is one of the three major groups (clades) of dinosaurs, alongside Ornithischia and Sauropodom ...

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

from the Griman Creek Formation of

New South Wales New South Wales (commonly abbreviated as NSW) is a States and territories of Australia, state on the Eastern states of Australia, east coast of :Australia. It borders Queensland to the north, Victoria (state), Victoria to the south, and South ...

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

, dating to the

Cenomanian The Cenomanian is, in the International Commission on Stratigraphy's (ICS) geological timescale, the oldest or earliest age (geology), age of the Late Cretaceous epoch (geology), Epoch or the lowest stage (stratigraphy), stage of the Upper Cretace ...

age of the

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...

period. It contains only the

type species In International_Code_of_Zoological_Nomenclature, 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 spe ...

, ''Rapator ornitholestoides'', which was originally named by

Friedrich von Huene Baron Friedrich Richard von Hoyningen-Huene (22 March 1875 – 4 April 1969) was a German nobleman paleontologist who described a large number of dinosaurs, more than anyone else in 20th-century Europe. He studied a range of Permo-Carbonife ...

in 1932.Huene, F. von. (1932). ''Die fossile Reptil-Ordnung Saurischia, ihre Entwicklung und Geschichte''. Monogr. Geol. Pal. 4 (1) pts. 1 and 2, viii + 361 pp.

Discovery

The

holotype A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of s ...

and only known specimen, BMNH R3718, consists of a single left hand bone, discovered around 1905 near Wollaston, on Lightning Ridge. The fossil has been

opal Opal is a hydrated amorphous form of silicon dioxide, silica (SiO2·''n''H2O); its water content may range from 3% to 21% by weight, but is usually between 6% and 10%. Due to the amorphous (chemical) physical structure, it is classified as a ...

ised. The meaning of the generic name is problematic. Von Huene gave no

etymology Etymology ( ) is the study of the origin and evolution of words—including their constituent units of sound and meaning—across time. In the 21st century a subfield within linguistics, etymology has become a more rigorously scientific study. ...

. "Rapator" does not exist in

Classical Latin Classical Latin is the form of Literary Latin recognized as a Literary language, literary standard language, standard by writers of the late Roman Republic and early Roman Empire. It formed parallel to Vulgar Latin around 75 BC out of Old Latin ...

and occurs only very rarely in

Mediaeval Latin Medieval Latin was the form of Literary Latin used in Roman Catholic Western Europe during the Middle Ages. It was also the administrative language in the former Roman Provinces of Mauretania, Numidia and Africa Proconsularis under the Vandals, ...

with the meaning "violator". One possible explanation is that von Huene, having been influenced by

Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

''raptare'', "to plunder", mistakenly thought such a word actually existed with the meaning of "plunderer". It has also been considered a simple misspelling of, or confusion with, ''raptor'', "seizer" or "thief".Long, J.A. (1998). ''Dinosaurs of Australia and New Zealand and Other Animals of the Mesozoic Era'', Harvard University Press, p. 104 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 ...

means "resembling ''

Ornitholestes ''Ornitholestes'' (meaning "bird robber") is a small theropod dinosaur of the late Jurassic ( Brushy Basin Member of the Morrison Formation, middle Kimmeridgian age, about 154 million years agoTurner, C.E. and Peterson, F., (1999). "Biostratigrap ...

''". Remains of a megaraptorid, nicknamed "Lightning Claw," were discovered in opal fields southwest of Lightning Ridge, Australia, may well represent more material of ''Rapator''.

Description

The only known bone has a length of . This manual element shows a prominent dorsomedial process, a feature shared with the much smaller ''Ornitholestes'' which occasioned the specific name. The process with ''Ornitholestes'' is much less distinctive though. On its upper end there is only one cotyle, from which von Huene deduced it must have been a metacarpal. However, several coelurosaurian groups also lack a second cotyle on the first phalanx. If ''Rapator'' had a build like ''Australovenator'', it would have attained a considerable size: a body length of has been estimated.

Classification

The type specimen of ''Rapator'' was originally described as a

metacarpal In human anatomy, the metacarpal bones or metacarpus, also known as the "palm bones", are the appendicular bones that form the intermediate part of the hand between the phalanges (fingers) and the carpal bones ( wrist bones), which articulate ...

I, a bone from the upper part of a theropod's hand. It was later noted that the bone is similar to a finger bone, the first

phalanx The phalanx (: phalanxes or phalanges) was a rectangular mass military formation, usually composed entirely of heavy infantry armed with spears, pikes, sarissas, or similar polearms tightly packed together. The term is particularly used t ...

of the first finger, of an alvarezsaurHoltz, Molnar, and Currie (2004). "Basal Tetanurae." In Weishampel, Dodson and Osmolska (eds.), ''The Dinosauria Second Edition.'' University of California Press. 861 pp. or of a primitive

coelurosauria Coelurosauria (; from Greek, meaning "hollow-tailed lizards") is the clade containing all theropod dinosaurs more closely related to birds than to carnosaurs. Coelurosauria is a subgroup of theropod dinosaurs that includes compsognathids, tyra ...

n similar to ''

Nqwebasaurus ''Nqwebasaurus'' is a Basal (phylogenetics), basal Coelurosauria, coelurosaur and the basal-most member of the coelurosaurian clade Ornithomimosauria from the Early Cretaceous of South Africa. The name ''Nqwebasaurus'' is derived from the Xhosa l ...

''.Salisbury, Agnolin, Ezcurra, and Pias (2007). "A critical reassessment of the Cretaceous non-avian dinosaur faunas of Australia and New Zealand." ''Journal of Vertebrate Paleontology'', 27(3): 138A. With the discovery of '' Australovenator'', which had a similar metacarpal, ''Rapator'' was recognized as a probable

megaraptora Megaraptora is a clade of carnivorous theropod dinosaurs. Its derived members, the Megaraptoridae are noted for their large hand claws and powerfully-built forelimbs, which are usually reduced in size in other large theropods. Although undoubt ...

n. In fact, ''Australovenator'' and ''Rapator'' differ only in some small details of the bone and may be synonyms, though Agnolin and colleagues in 2010 considered ''Rapator'' a dubious genus (''

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 ...

'') due to its fragmentary nature.Agnolin, Ezcurra, Pais and Salisbury, (2010). "A reappraisal of the Cretaceous non-avian dinosaur faunas from Australia and New Zealand: Evidence for their Gondwanan affinities." ''Journal of Systematic Palaeontology'', 8(2): 257-300. However, White ''et al.'' found differences between the hand bone of ''Rapator'' and the equivalent bone of ''Australovenator'', supporting the distinction between the two. They also noted that the two genera come from formations separated chronologically by at least 10 million years, making them unlikely to be synonymous. ''Rapator'' has been synonymised with '' Walgettosuchus'', a theropod found in the same formation.Steel, R. (1970) ''Handbuch der Paläoherpetologie/Encyclopedia of Paleoherpetology. Part 14. Saurischia''. Gustav Fischer Verlag, Stuttgart 1-87 As the latter is only known from a caudal vertebra, the identity cannot be proven.

References

External links

''Rapator'' in The Theropod Database

''Rapator''
{{Taxonbar, from=Q1577331 Megaraptora Dinosaur genera Cenomanian dinosaurs Taxa named by Friedrich von Huene Fossil taxa described in 1932 Dinosaurs of Australia