''Iliosuchus'' (meaning "crocodile hipped") 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 ...

known from

Bathonian In the geologic timescale the Bathonian is an age and stage of the Middle Jurassic. It lasted from approximately 168.3 Ma to around 166.1 Ma (million years ago). The Bathonian Age succeeds the Bajocian Age and precedes the Callovian Age. Str ...

–age (168.3 – 166.1 mya) rocks of

England England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe b ...

. It was perhaps long.Holtz, Thomas R. Jr. (2008) ''Dinosaurs: The Most Complete, Up-to-Date Encyclopedia for Dinosaur Lovers of All Ages'
Supplementary Information
/ref> The only known fossils of this genus are three ilia ( BMNH R83, OUM J29780 and OUM J28971) from the Stonesfield Slate, Oxfordshire,

. From 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 sever ...

BMNH R83, Friedrich von Huene described and named the only species, ''I. incognitus'', in 1932. The generic name is derived from the ilium and Greek ''Souchos'', the crocodile god. The specific name means "unknown" in

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 ...

. Another species, ''I. clevelandi'', was proposed in 1976 by

Peter Galton Peter Malcolm Galton (born 14 March 1942 in London) is a British vertebrate paleontologist who has to date written or co-written about 190 papers in scientific journals or chapters in paleontology textbooks, especially on ornithischian and prosa ...

, who assigned '' Stokesosaurus clevelandi'' to ''Iliosuchus'', but this has found no acceptance among other researchers; in 1980 Galton himself withdrew his opinion. The ''Iliosuchus'' ilia, very small with a length of nine to ten centimetres, have a vertical supra–

acetabular The acetabulum (), also called the cotyloid cavity, is a concave surface of the pelvis. The head of the femur meets with the pelvis at the acetabulum, forming the hip joint. Structure There are three bones of the ''os coxae'' (hip bone) that ...

ridge on the surface, similar to

tyrannosaurid Tyrannosauridae (or tyrannosaurids, meaning "tyrant lizards") is a family of coelurosaurian theropod dinosaurs that comprises two subfamilies containing up to thirteen genera, including the eponymous ''Tyrannosaurus''. The exact number of genera ...

s and many other predatory dinosaurs belonging to the group

Tetanurae Tetanurae (/ˌtɛtəˈnjuːriː/ or "stiff tails") is a clade that includes most theropod dinosaurs, including megalosauroids, allosauroids, tyrannosauroids, ornithomimosaurs, compsognathids and maniraptorans (including birds). Tetanurans ar ...

, including ''

Piatnitzkysaurus ''Piatnitzkysaurus'' ( meaning "Piatnitzky's lizard") is a genus of megalosauroid theropod dinosaur that lived approximately 179 to 177 million years ago during the lower part of the Jurassic Period in what is now Argentina. ''Piatnitzkysaurus'' ...

'' and ''

Megalosaurus ''Megalosaurus'' (meaning "great lizard", from Greek , ', meaning 'big', 'tall' or 'great' and , ', meaning 'lizard') is an extinct genus of large carnivorous theropod dinosaurs of the Middle Jurassic period (Bathonian stage, 166 million years ...

''.Benson, R.B.J. (2009). "An assessment of variability in theropod dinosaur remains from the Bathonian (Middle Jurassic) of Stonesfield and New Park Quarry, UK and taxonomic implications for ''Megalosaurus bucklandii'' and ''Iliosuchus incognitus''." ''Palaeontology'' 52 857-877

/ref> Such fragmentary and incomplete material is inadequate for accurate classification; nonetheless, ''Iliosuchus'' has sometimes been considered a tyrannosaurid ancestor. This is unlikely to be correct as the bones cannot be distinguished from small individuals of ''Megalosaurus'', a megalosaurid. Whatever the case, ''Iliosuchus'' is not diagnostic and is therefore nomen dubium, dubious. If ''Iliosuchus incognitus'' is a tyrannosauroid, it would be a possible ancestor to ''

Proceratosaurus ''Proceratosaurus'' is a genus of carnivorous theropod dinosaur from the Middle Jurassic ( Bathonian) of England. ''Proceratosaurus'' was a small dinosaur, measuring in length and in body mass.Holtz, Thomas R. Jr. (2008) ''Dinosaurs: The Mos ...

'', the earliest recognized tyrannosauroid, and would be the earliest of the tyrannosauroids.

References

{{Taxonbar, from=Q1920187 Prehistoric coelurosaurs Bathonian life Middle Jurassic dinosaurs of Europe Jurassic England Fossils of England Fossil taxa described in 1932 Taxa named by Friedrich von Huene Nomina dubia

See also

References