''Ozraptor'' (meaning "Australian thief") is a genus of possibly abelisauroid

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 Middle

Jurassic The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The J ...

(

Bajocian In the geologic timescale, the Bajocian is an age and stage in the Middle Jurassic. It lasted from approximately 170.3 Ma to around 168.3 Ma (million years ago). The Bajocian Age succeeds the Aalenian Age and precedes the Bathonian Age. Stratig ...

)

Colalura Sandstone The Colalura Sandstone is a Middle Jurassic geologic formation of the Perth Basin of Western Australia. The formation overlies the Moonyoonooka Sandstone. Dinosaur remains have been recovered from the formation. Vertebrate paleofauna Few ...

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 ...

, known from fragmentary remains.

Discovery and naming

In 1967 a group of four twelve-year-old Scotch College schoolboys found a

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

at the Bringo Railway Cutting site near

Geraldton Geraldton (Wajarri: ''Jambinu'', Wilunyu: ''Jambinbirri'') is a coastal city in the Mid West region of the Australian state of Western Australia, north of the state capital, Perth. At June 2018, Geraldton had an urban population of 37,648. ...

, which they showed to professor Rex Prider of the

University of Western Australia The University of Western Australia (UWA) is a public research university in the Australian state of Western Australia. The university's main campus is in Perth, the state capital, with a secondary campus in Albany, Western Australia, Albany an ...

. He had a cast made that he sent to experts of the

British Museum of Natural History The Natural History Museum in London is a museum that exhibits a vast range of specimens from various segments of natural history. It is one of three major museums on Exhibition Road in South Kensington, the others being the Science Museum an ...

London London is the capital and largest city of England and the United Kingdom, with a population of just under 9 million. It stands on the River Thames in south-east England at the head of a estuary down to the North Sea, and has been a majo ...

who thought it likely belonged to an extinct

turtle Turtles are an order of reptiles known as Testudines, characterized by a special shell developed mainly from their ribs. Modern turtles are divided into two major groups, the Pleurodira (side necked turtles) and Cryptodira (hidden necked tu ...

. Re-evaluation of the bone in the 1990s after being prepared out of the rock by John Albert Long and

Ralph Molnar Ralph E. Molnar is a paleontologist who had been Curator of Mammals at the Queensland Museum and more recently associated with the Museum of Northern Arizona. He is also a research associate at the Texas natural Science Centre. He co-authored descr ...

classified the fossil as the shinbone of a genus of

s.Long, J.A. (1998). ''Dinosaurs of Australia and New Zealand and other animals of the Mesozoic Era''. Harvard University Press, UNSW Press, pp 94-96. In 1998 Long and Molnar named and described the type (and only) species ''Ozraptor subotaii''. The generic name is derived from "Ozzies", the nickname for Australians, and a

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 ...

''raptor'', "seizer". The specific name honours a fictional character, the swift-running thief and archer "Subotai" from the movie ''

Conan the Barbarian Conan the Barbarian (also known as Conan the Cimmerian) is a fictional sword and sorcery hero who originated in pulp magazines and has since been adapted to books, comics, films (including '' Conan the Barbarian'' and '' Conan the Destroyer'') ...

''. 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 ...

, UWA 82469, was found in the

, dating to the middle Bajocian, about 169 million years ago. It consists of the

distal Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position pro ...

or lower end of a left

tibia The tibia (; ), also known as the shinbone or shankbone, is the larger, stronger, and anterior (frontal) of the two bones in the leg below the knee in vertebrates (the other being the fibula, behind and to the outside of the tibia); it connects ...

. Together with ''

Rhoetosaurus ''Rhoetosaurus'' (meaning "Rhoetos lizard"), named after Rhoetus, a titan in Greek Mythology, is a genus of sauropod dinosaur from the Jurassic ( Oxfordian) Walloon Coal Measures of what is now eastern Australia. ''Rhoetosaurus'' is estimated t ...

'', ''Ozraptor'' is among the oldest known Australian dinosaurs. The specimen is long and wide at the lower end. From these measurements, a total length for the shinbone was estimated of about and for the animal as a whole of about . Three diagnostic features were established enabling it to be upheld as a distinct species of dinosaur: the ascending process of the

astragalus ''Astragalus'' is a large genus of over 3,000 species of herbs and small shrubs, belonging to the legume family Fabaceae and the subfamily Faboideae. It is the largest genus of plants in terms of described species. The genus is native to tempe ...

had a rectangular shape with a straight upper end; the astragalar facet had a vertical ridge; the medial

condyle A condyle (;Entry "condyle"
in
Theropoda 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 ca ...

incertae sedis ' () or ''problematica'' is a term used for a taxonomic group where its broader relationships are unknown or undefined. Alternatively, such groups are frequently referred to as "enigmatic taxa". In the system of open nomenclature, uncertainty ...

''. In 2004

Thomas Holtz Thomas Richard Holtz Jr. (born September 13, 1965) is an American vertebrate palaeontologist, author, and principal lecturer at the University of Maryland's Department of Geology. He has published extensively on the phylogeny, morphology, ecomorp ...

thought it was a member of the

Avetheropoda Avetheropoda, or "bird theropods", is a clade that includes carnosaurians and coelurosaurs to the exclusion of other dinosaurs. Definition Avetheropoda was named by Gregory S. Paul in 1988, and was first defined as a clade by Currie and Padian i ...

. In 2005 another study, by

Oliver Rauhut Oliver may refer to: Arts, entertainment and literature Books * ''Oliver the Western Engine'', volume 24 in ''The Railway Series'' by Rev. W. Awdry * '' Oliver Twist'', a novel by Charles Dickens Fictional characters * Ariadne Oliver ...

, suggested that it was indeed a theropod, and more specifically, a member of the

Abelisauroidea Abelisauroidea is typically regarded as a Cretaceous group, though the earliest abelisauridae remains are known from the Middle Jurassic of Argentina (classified as the species Eoabelisaurus mefi) and possibly Madagascar (fragmentary remains of ...

based on the presence of the distinct vertical median ridge on the astragalar groove. Classified as one, ''Ozraptor'' would be the oldest known abelisauroid. However, Rauhut would later go on to conclude that none of these defining chararcterists are actually limited to the abelisaurs, and thus ''Ozraptor'' can at best be classified as ''Theropoda indet''.Rauhut, O.W.M. (2012). "A reappraisal of a putative record of abelisauroid theropod dinosaur from the Middle Jurassic of England." Proceedings of the Geologists' Association. 123(5), 779-786.

References

{{Taxonbar, from=Q2147651 Abelisaurs Middle Jurassic dinosaurs Dinosaurs of Australia Mesozoic reptiles of Australia Bajocian life Fossil taxa described in 1998 Taxa named by Ralph Molnar

Discovery and naming

See also

References