The genus contains a single species, D. normani, known from a fragmentary knee joint and femur that were initially described by Sir Richard Owen as belonging to the early armored dinosaur Scelidosaurus.

[1] In 1858, Richard Owen received fragmentary dinosaur leg bones discovered by James Harrison in Charmouth, Dorset.

[2] The informal name "Merosaurus newmani" was coined by Samuel Paul Welles, H. P. Powell, and Stephan Pickering in 1995 in an unpublished manuscript for the theropod material.

[10][8][9] While specimens NHMUK 39496 and GSM 109560 lack anatomical overlap, their discovery in the same stratigraphic unit, along with similar size and proportions, suggests they belong to the same taxon, distinct from earlier forms and contemporaneous taxa like Dracoraptor and Sarcosaurus.

Utilizing a modified version of the Baron et al. (2017) phylogenetic dataset,[11] Dornraptor was found to be an early-branching averostran theropod in a polytomy with Elaphrosaurus, Cryolophosaurus, and the clade containing Allosaurus and Piatnitzkysaurus.

[2] Following the formal description of Dornraptor, Mickey Mortimer discussed it on the Theropod Database blog, noting that some of the characters used by researchers to exclude tetanuran affinities for the holotype are found in some basal members of this clade, such as Chuandongocoelurus, Dubreuillosaurus, and Eustreptospondylus.

[13][14] Inner continental landmasses were an archipelago of large islands inherited from Caledonian and Variscan massifs, where the Dorset area was part of the Wessex Basin, bordered by the London-Brabant, Armorican, Cornubian, and Welsh Massifs, divided into sub-basins by east-west faults that were the source for siliclastic material, as recorded in coeval boreholes.

[13] Other dinosaurs from the locality include the well-known thyreophoran Scelidosaurus, as well as indeterminate theropod remains suggesting smaller Coelophysis-sized taxa, with Dornraptor likely being the terrestrial apex predator.

Palynology indicates the presence of taxa like the "seed ferns" Alisporites, the "cycadophyte" Chasmatosporites, and the dominant Hirmeriellaceae conifer Corollina and Classopollis, suggesting arid or semiarid environments, usually compared with modern Mediterranean islands.