''Rapator'' is a

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 ...

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

Griman Creek Formation The Griman Creek Formation is a geological formation in northern New South Wales and southern Queensland, Australia whose strata date back to the Albian-Cenomanian of the Early-Late Cretaceous.Bell et al., 2019 It is most notable being a major so ...

New South Wales ) , nickname = , image_map = New South Wales in Australia.svg , map_caption = Location of New South Wales in AustraliaCoordinates: , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , es ...

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

, dating to the

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 ± 0.9 M ...

Cenomanian The Cenomanian is, in the ICS' geological timescale, the oldest or earliest age of the Late Cretaceous Epoch or the lowest stage of the Upper Cretaceous Series. An age is a unit of geochronology; it is a unit of time; the stage is a unit in the s ...

ages 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, 105-96 million years ago. It contains only 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 ...

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

Friedrich von Huene Friedrich von Huene, born Friedrich Richard von Hoinigen, (March 22, 1875 – April 4, 1969) was a German paleontologist who renamed more dinosaurs in the early 20th century than anyone else in Europe. He also made key contributions about v ...

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 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 ...

and only known specimen, BMNH R3718, consists of a single left hand bone, discovered around 1905 near Wollaston, on

Lightning Ridge Lightning Ridge is a small outback town in north-western New South Wales, Australia. Part of Walgett Shire, Lightning Ridge is situated near the southern border of Queensland, about east of the Castlereagh Highway. The Lightning Ridge area is ...

. The fossil has been

opal Opal is a hydrated amorphous form of silica (SiO2·''n''H2O); its water content may range from 3 to 21% by weight, but is usually between 6 and 10%. Due to its amorphous property, it is classified as a mineraloid, unlike crystalline forms ...

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

etymology Etymology ()The New Oxford Dictionary of English (1998) – p. 633 "Etymology /ˌɛtɪˈmɒlədʒi/ the study of the class in words and the way their meanings have changed throughout time". is the study of the history of the Phonological chan ...

. "Rapator" does not exist in

Classical Latin Classical Latin is the form of Literary Latin recognized as a literary standard by writers of the late Roman Republic and early Roman Empire. It was used from 75 BC to the 3rd century AD, when it developed into Late Latin. In some later periods ...

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. In this region it served as the primary written language, though local languages were also written to varying degrees. Latin functioned ...

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 branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...

''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 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). "Biostratigraph ...

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

Description

The bone has a length of seven centimetres. 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 :''The cotylae are also features on the proximal end of the radius and of the ulna in birds.'' In classical antiquity, the cotyla or cotyle () was a measure of capacity among the Greeks and Romans: by the former it was also called ; by the latte ...

, from which von Huene deduced it must have been a metacarpal. However, several coelurosaurian groups lack a second cotyle on the first phalanx also. If ''Rapator'' had a build like ''Australovenator'', it would have attained a considerable size: a body length of nine metres (30 ft) has been estimated.

Classification

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

metacarpal In human anatomy, the metacarpal bones or metacarpus form the intermediate part of the skeletal hand located between the phalanges of the fingers and the carpal bones of the wrist, which forms the connection to the forearm. The metacarpal bones ...

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 ( grc, φάλαγξ; plural phalanxes or phalanges, , ) was a rectangular mass military formation, usually composed entirely of heavy infantry armed with spears, pikes, sarissas, or similar pole weapons. The term is particularly use ...

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, tyrann ...

n similar to ''

Nqwebasaurus ''Nqwebasaurus'' (; anglicized as or ) is a basal coelurosaur and is the basal-most member of the coelurosaurian clade Ornithomimosauria from the Early Cretaceous of South Africa. The name ''Nqwebasaurus'' is derived from the Xhosa word "Nqweb ...

''.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 ''Australovenator'' (meaning "southern hunter") is a genus of megaraptoran theropod dinosaur from Cenomanian (Late Cretaceous)-age Winton Formation (dated to 95 million years ago) of Australia. It is known from partial cranial and postcranial r ...

'', which had a similar metacarpal, ''Rapator'' was recognized as a probable

megaraptora Megaraptora is a clade of carnivorous Tetanurae, tetanuran theropod dinosaurs with controversial relations to other theropods. Its Derived (phylogenetics), derived members, the Megaraptoridae are noted for their elongated hand claws and proporti ...

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 s ...

'') 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 Early Cretaceous dinosaurs of Australia Megaraptorans Fossil taxa described in 1932 Taxa named by Friedrich von Huene Paleontology in New South Wales