page_title: Scelidosaurus
section_title: History of discovery
hierarchical_section_title: Scelidosaurus / History of discovery
caption_attribution_description: Bones of a juvenile Scelidosaurus.
context_page_description: Scelidosaurus is a genus of herbivorous armoured ornithischian dinosaur from the Jurassic of England.
  Scelidosaurus lived during the Early Jurassic Period, during the Sinemurian to Pliensbachian stages around 191 million years ago. This genus and related genera at the time lived on the supercontinent Laurasia. Its fossils have been found near Charmouth in Dorset, England, and are known for their excellent preservation. Scelidosaurus has been called the earliest complete dinosaur. It is the most completely known dinosaur of the British Isles. Scelidosaurus is currently the only classified dinosaur found in Ireland. Despite this, a modern description only materialised in 2019. After initial finds in the 1850s, comparative anatomist Richard Owen named and described Scelidosaurus in 1859. Only one species, Scelidosaurus harrisonii named by Owen in 1861, is considered valid today, although one other species was proposed in 1996.
  Scelidosaurus was about 4 metres long. It was a largely quadrupedal animal, feeding on low scrubby plants, the parts of which were bitten off by the small, elongated head to be processed in the large gut.
context_section_description: During the 1850s, quarry owner James Harrison of Charmouth, West Dorset of England found fossils from the cliffs of Black Ven between Charmouth and Lyme Regis, that were quarried, possibly for raw material for the manufacture of cement. Some of these he gave to the collector and retired general surgeon Henry Norris. In 1858, Norris and Harrison sent some fragmentary limb bones to Professor Richard Owen of the British Museum (Natural History), London (today the Natural History Museum). Among them was a left thighbone, specimen GSM 109560. In 1859, Owen named the genus Scelidosaurus in an entry about palaeontology in the Encyclopædia Britannica. The lemma text contained a diagnosis, implicating that the genus was validly named and was not a nomen nudum, despite the fact that the definition was vague and no specimens were identified. Owen intended to call the dinosaur "hindlimb saurian" but confused the Greek word σκέλος, skelos, "hindlimb", with σκελίς, skelis, "rib of beef". The name was inspired by the strong development of the hind leg. Afterwards Harrison sent a knee joint, a claw (GSM 109561), a juvenile specimen and a skull to Owen, that were described in 1861. On that occasion the type species Scelidosaurus harrisonii was named, the specific name honouring Harrison. The skull later was revealed to be part of a nearly complete skeleton, that was described by Owen in 1863.
  British palaeontologist David Bruce Norman has stressed how remarkable it is that Owen, who previously had propounded that dinosaurs were active quadrupedal animals, largely neglected Scelidosaurus though it could serve as a prime example of this hypothesis and its fossil was one of the most complete dinosaurs found at that time. Norman explained this by Owen's excessive workload in this period, including several administrative functions, polemics with fellow-scientists and the study of a large number of even more interesting newly discovered extinct animals, such as Archaeopteryx. Norman also pointed out that Owen in 1861 suggested a lifestyle for Scelidosaurus that is very different from present ideas: it would have been a fish-eater and partially sea-dwelling.
  Owen had not indicated a holotype. In 1888, Richard Lydekker while cataloguing the BMNH fossils, designated some of the hindlimb fragments described in 1861, specimen BMNH 39496 consisting of a lower part of a femur and an upper part of the tibia and fibula, together forming a knee joint, as the type specimen, hereby implicitly choosing them as the lectotype of Scelidosaurus. Lydekker gave no reason for this choice; perhaps he was motivated by their larger size. Unfortunately, mixed in with the Scelidosaurus fossils had been the partial remains of a theropod dinosaur and the femur and tibia thus belonged to such a carnivore; this was not discovered until 1968 by Bernard Newman. The same year, B. H. Newman suggested to have Lydekker's selection of the knee joint as the lectotype officially rescinded by the International Commission on Zoological Nomenclature, as the joint was in his opinion from a species related to Megalosaurus. Eventually, after Newman had already died, Alan Jack Charig actually filed a request in 1992. In 1994 the ICZN reacted positively, in Opinion 1788 deciding that the skull and skeleton, specimen BMNH R.1111, would be the neotype of Scelidosaurus. The knee joint was in 1995 by Samuel Welles et al. informally assigned to a "Merosaurus", which name has not yet been validly published. It more likely belongs to some member of the Coelophysoidea or Neoceratosauria. It has also been established by Newman and confirmed by Roger Benson that the original left thigbone, GSM 109560, belonged to a theropod.
  The neotype skeleton had been uncovered in the Black Ven Marl or Woodstone Nodule Bed, marine deposits of the Charmouth Mudstone Formation, dating from the late Sinemurian stage, about 191 million years ago. It consists of a rather complete skeleton with skull and lower jaws. Only the snout tip, the neck base, the forelimbs and the tail end are missing. Hundreds of osteoderms w
caption: Philpot's specimen
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