The holotype was discovered in 1863.[1] It was first described by Thomas Henry Huxley in 1867 based on holotype NHMUK R1626, a proximal end of a left tibia (misidentified as a distal femur).[2] However, Huxley declined to provide a species name. In his 1889 catalogue of fossil reptiles in the Natural History Museum in London, Richard Lydekker mistakenly considered Orosaurus preoccupied by the lizard genus Oreosaurus and coined Orinosaurus capensis for NHMUK R1626. Along with Euskelosaurus, Lydekker considered Orosaurus (Orinosaurus of his usage) to be an ornithischian dinosaur.[3]
von Huene (1940) treated Orosaurus as a species of Euskelosaurus, as E. capensis.[4] van Heerden (1979) considered Orosaurus a synonym of Euskelosaurus.[5] However, Gauffre (1996) referred Orosaurus to his nomen ex dissertationae "Kholumolumosaurus" (now Kholumolumo) along with Meroktenos and Plateosauravus.[6] Meanwhile, Orosaurus was listed as a nomen dubium in the 2nd edition of The Dinosauria.[7]
^T. H. Huxley. 1866. On some remains of large dinosaurian reptiles from the Stormberg Mountains, South Africa. Quarterly Journal of the Geological Society of London 23(1):1-6
^Huxley, T. H., 1867, On some remains of large dinosaurian reptiles from the Stormberg Mountains, South Africa: Quarterly Journal of the Geological Society of London, v. 23, p. 5
^Lydekker, R., 1889. Note on new and other dinosaurian remains: Geological Magazine, decade 3, v. 6, p. 352-356.
^Huene F von (1940) "Die Saurier der Karroo-, Gondwana-, und verwandten Ablagerungen in faunistischer, biologischer und phylogenetischer Hinsicht" [Saurians of the Karroo, Gondwana, and other deposits in faunistic, biological, and phylogenetic regard]. Neues Jahrbuch für Mineralogie, Geologie und Paläontologie, Beilage-Band, Abteilung B 83:246-347.
^Heerden J. v. (1979) The morphology and taxonomy of Euskelosaurus (Reptilia: Saurischia; Late Triassic) from South Africa". Navorsinge van die Nasionale Museum, 4(2): 21-84.
^Gauffre F-X. 1996. Phylogénie des dinosaures prosauropodes et étude d'un prosauropode du trias supérieur d'Afrique Australe. PhD Thesis. Museum national d'histoire naturelle, Paris.
^Galton, P.M & Upchurch, P. (2004). "Prosauropoda". In D. B. Weishampel, P. Dodson, & H. Osmólska (eds.), The Dinosauria (second edition). University of California Press, Berkeley: 232–258.