Editing Kentrosaurus (section)

=== Skull and dentition ===
Eight specimens from the skull, mandible, and teeth have been collected and described from the Tendaguru Formation, most of them being isolated elements.<ref name=":2">Galton, P. M. (1988). [https://www.researchgate.net/profile/Peter-Galton/publication/272152710_Skull_bones_and_endocranial_casts_of_stegosaurian_dinosaur_Kentrosaurus_Hennig_1915_from_Upper_Jurassic_of_Tanzania_East_Africa/links/554197010cf2b790436be3bf/Skull-bones-and-endocranial-casts-of-stegosaurian-dinosaur-Kentrosaurus-Hennig-1915-from-Upper-Jurassic-of-Tanzania-East-Africa.pdf Skull bones and endocranial casts of stegosaurian dinosaur Kentrosaurus Hennig, 1915 from Upper Jurassic of Tanzania, East Africa.] ''Geologica et Palaeontologica'', ''22'', 123-143.</ref> Two [[Quadrate bone|quadrates]] (bones from the jaw joint) were referred to ''Kentrosaurus'', but they instead belong to a juvenile [[Brachiosauridae|brachiosaurid]].<ref>Maidment, S. C., Norman, D. B., Barrett, P. M., & Upchurch, P. (2008). Systematics and phylogeny of Stegosauria (Dinosauria: Ornithischia). ''Journal of Systematic Palaeontology'', ''6''(4), 367-407.</ref>
[[File:KentrosaurusBraincase(HMN St 460).jpg|left|thumb|Braincase of ''Kentrosaurus'' in lateral view.]]
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 [[archosaur]]s, 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 [[Beak#Anatomy|rhamphotheca]]. The presence of a beak extended along much of the jaws may have precluded the presence of cheeks in stegosaurs.<ref name="czerkas1999">{{cite journal |last1=Czerkas |first1=S |year=1999 |title=The beaked jaws of stegosaurs and their implications for other ornithischians |journal=Miscellaneous Publication of the Utah Geological Survey |volume=99–1 |pages=143–150}}</ref> Due to its phylogenetic position, it is unlikely that ''Kentrosaurus'' had an extensive beak like ''Stegosaurus'' and it instead probably had a beak restricted to the jaw tips.<ref name="knoll2008">{{cite journal |last1=Knoll |first1=F |year=2008 |title=Buccal soft anatomy in ''Lesothosaurus'' (Dinosauria: Ornithischia) |url=https://www.researchgate.net/publication/233720216 |format=PDF |journal=Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen |volume=248 |issue=3 |pages=355–364 |doi=10.1127/0077-7749/2008/0248-0355|bibcode=2008NJGPA.248..355K }}</ref><ref name="barrett2001">Barrett, P.M. (2001). Tooth wear and possible jaw action of ''Scelidosaurus harrisonii'' Owen and a review of feeding mechanisms in other thyreophoran dinosaurs. Pp. 25-52 in Carpenter, K. (ed.): ''The Armored Dinosaurs''. Bloomington: Indiana University Press.</ref> Other researchers have interpreted these ridges as modified versions of similar structures in other ornithischians which might have supported fleshy cheeks, rather than beaks.<ref name="dinosauria04">{{cite book |title=The Dinosauria |vauthors=Galton PM, Upchurch P |publisher=University of California Press |year=2004 |isbn=978-0-520-24209-8 |veditors=Weishampel DB, Dodson P, Osmólska H |edition=2nd |chapter=Stegosauria}}</ref>

There are two nearly complete [[Neurocranium|braincases]] known from ''Kentrosaurus'' though they exhibit some taphonomic distortion.<ref name=":2" /> The [[Frontal bone|frontals]] and [[Parietal bone|parietals]] are flat and broad, with the latter bearing two transversely concave ventral sides with a ridge running down the middle that divides them. The lateral surface of the frontals form part of the [[Orbit (anatomy)|orbit]] (eye socket) and the medial side creates the anterior part of the [[Endocranium|endocranial cavity]] (braincase). [[Basilar part of occipital bone|Basioccipitals]] (where the skull articulated with the cervical vertebrae) form the posterior floor of the brain and the [[Occipital condyles|occipital condyle]], which is large and spherical in ''Kentrosaurus''. The rest of the braincase is formed by the [[Sphenoid bone|presphenoid]] composing the anterior end. The overall braincase morphology is very similar to those of ''[[Tuojiangosaurus]]'', ''[[Huayangosaurus]]'', and ''[[Stegosaurus]]''. However, the occipital condyle is a closer distance to the [[Sphenoid bone|basisphenoid tubera]] (bone at the front of the braincase) in ''Kentrosaurus'' and ''Huayangosaurus'' than in ''Tuojiangosaurus'' and some specimens of ''Stegosaurus''. Due to dinosaurs having more molding in their braincases, [[endocast]]s of ''Kentrosaurus'' can be reconstructed using the preserved fossils. The brain is relatively short, deep, and small, with a strong [[Cerebral cortex|cerebral]] and [[pontine flexures]] and a steeply inclined posterodorsal edge when compared to those of other ornithischians. There is a small dorsal projection in the endocast where an unossified (lacking bone) region between the top of the [[supraoccipital]] (bone at the top-back of the braincase) and overlying parietal that was likely covered in [[cartilage]]. This characteristic is seen in other ornithischians. Because of the prominent flexures, many of the aspects of the brain can only be interpreted by the present structures.<ref name=":2" />

[[File:Fossil Kentrosaurus aethiopicus in Museum für Naturkunde Berlin 002.JPG|thumb|Skull and neck of the Berlin mount]]
In the [[mandible]] (lower jaw), only an incomplete right dentary is known from ''Kentrosaurus''.<ref>Hennig, E. (1936). Ein dentale von Kentrurosaurus aethiopicus Hennig. ''Palaeontographica-Supplementbände'', 309-312.</ref> The deep dentary is almost identical in shape to that of ''Stegosaurus'', albeit much smaller. Similarly, the tooth is a typical stegosaurian tooth, small with a widened base and vertical grooves creating five ridges. The dentary has 13 preserved [[Dental alveolus|alveoli]] on the dorsomedial side and they are slightly convex in lateral and dorsal views. On the surface adjacent to the alveoli, there is a shallow groove bearing small [[Vertebra|foramina]] (small openings in bone) that is similar to grooves on the dentary of the [[Cretaceous]] neornithischian ''[[Hypsilophodon]]'', with one foramina per tooth position. Stegosaurian teeth were small, triangular, and flat; wear facets show that they did grind their food.<ref name="FasWeis04">{{cite book |title=The Evolution and Extinction of the Dinosaurs |vauthors=Fastovsky DE, Weishampel DB |publisher=Cambridge University Press |year=2005 |isbn=978-0-521-81172-9 |veditors=Fastovsky DE, Weishampel DB |edition=2nd |pages=107–30 |chapter=Stegosauria: Hot Plates}}</ref> A single complete cheek tooth is preserved, with a large crown and long root. The crown notably has fewer marginal [[Denticle (tooth feature)|denticles]] and a prominent [[Cingulum (tooth)|cingulum]] compared to ''Stegosaurus'', ''Tuojiangosaurus'', and ''Huayangosaurus''.<ref name=":2" />