Hennig in 1915, i.e. all the bones discovered before 1912, when Hermann Heck concluded the last German excavations, are paralectotypes, and that MB.R.4800 is the correct lectotype. Description Kentrosaurus was a small stegosaur. It had the typical dinosaurian body bauplan, characterised by a small head, a long neck, short forelimbs and long hindlimbs, and a long, horizontal and muscular tail. Typical stegosaurid traits included the elongation and flatness of the head, the powerful build of the forelimbs, erect and pillar-like hindlimbs and an array of plates and spikes running along both sides of the top mid-line of the animal. Size and posture Kentrosaurus aethiopicus was a relatively small stegosaur, reaching in length and in body mass. Some specimens suggest that relatively larger individuals could have existed. These specimens are comparable to some Stegosaurus specimens in terms of the olecranon process in development. The long tail of Kentrosaurus results in a position of the center of mass that is unusually far back for a quadrupedal animal. It rests just in front of the hip, a position usually seen in bipedal dinosaurs. However, the femora are straight in Kentrosaurus, as opposed to typical bipeds, indicating a straight and vertical limb position. Thus, the hindlimbs, though powered by massive thigh muscles attached to a long ilium, did not support the animal alone, and the very robust forelimbs took up 10 to 15% of the bodyweight. The center of mass was not heavily modified by the osteoderms (bony structures in skin) in Kentrosaurus or Stegosaurus, which allowed the animals to stay mobile despite their armament. The hindlimbs’ thigh muscles were very powerful, allowing Kentrosaurus to reach a tripod stance on its hindlegs and tail. Skull and dentition Eight specimens from the skull, mandible, and teeth have been collected an described from the Tendaguru Formation, most of them being isolated elements. Two quadrates (bones from the jaw joint) were referred to Kentrosaurus, but they instead belong to a juvenile brachiosaurid. The long and narrow skull was small in proportion to the body. It had a small antorbital fenestra, the hole between the nose and eye common to most archosaurs, including modern birds, though lost in extant crocodylians. The skull's low position suggests that Kentrosaurus may have been a browser of low-growing vegetation. This interpretation is supported by the absence of premaxillary teeth and their likely replacement by a horny beak or rhamphotheca. The presence of