[D] Loricatosaurus priscus [sG]
Maidment, Norman, Barrett & Upchurch 2008
Jurassic Middle Callovian
Ornithischia Thyreophora Stegosauria Stegosauridae
Oxford Clay Formation of Fletton, Peterborough, England
Loricatosaurus priscus (Maidment, Norman, Barrett & Upchurch 2008) > Stegosaurus priscus (Nopcsa, 1911)
Loricatus, from the Latin for armoured, saurus, from the Greek for reptile.
BMNHR3167, a partial skeleton, including two cervical vertebrae, six dorsal vertebrae, 16 caudal vertebrae, right humerus, right ulna, carpus, two metacarpals (one incomplete), partial ilia, partial right ischium and pubis, left femur, left partial tibia and partial fibula with fused tarsals, and dermal armour. A parascapular spine is not present (contra Nopcsa 1911b and Galton 1985; the element considered by the latter authors to be a parascapular spine is completely different in morphology to the parascapular spines of other stegosaurs and is probably a fragmentary tail spine). The specimen has been described and figured by Galton (1985).
MHBR 001, a partial skeleton (Hoffstetter 1957; Galton et al. 1980; Galton 1990b). The specimen includes cervical, dorsal and caudal vertebrae, left humerus, right femur, tibia and fibula and dermal armour.
Differs from other stegosaurs in possessing a first or second caudal vertebrawhose transverse processes are bifurcated distally. Other anterior caudal vertebrae bear small dorsal projections about two-thirds of the way along the transverse process. Mid-caudal vertebrae have large anterior and posterior chevron facets that converge ventrally, so that the vertebral centra are ‘V’ shaped in lateral view.
The holotype is from the Oxford Clay (Callovian: Middle Jurassic) of Fletton, Peterborough (Galton 1985); the referred specimen is from an unnamed unit (lower Callovian:Middle Jurassic) of Le Fresne d’Argences, Calvados, Normandy, France (Hoffstetter 1957; Galton et al. 1980; Galton 1990b).
The holotype specimen (BMNH R3167) was referred previously to Lexovisaurus durobrivensis by Hoffstetter (1957) and Galton (1985). However, the holotype of the latter taxon is undiagnostic (see below). Although BMNH R3167 was originally referred to Stegosaurus by Nopcsa (1911b), it is clearly not referable to that taxon because it possesses none of the autapomorphies of Stegosaurus and, in addition, it bears unique characters not observed in Stegosaurus