STEGOSAURUS

'''Stegosaurus''' () is a genus of stegosaurid armoured dinosaur from the Late Jurassic period (Kimmeridgian to Early Tithonian) in what is now western North America. In 2006, a specimen of ''Stegosaurus'' was announced from Portugal, suggesting that they were present in Europe as well.Escaso, F, Ortega, F., Dantas, P., Malafaia, E., Pimentel, N.L, Pereda-Suberbiola, X., Sanz, J.L., Kullberg, J.C., Kullberg, M.C., and Barriga, F. (2007). "New Evidence of Shared Dinosaur Across Upper Jurassic Proto-North Atlantic: ''Stegosaurus'' From Portugal." ''Naturwissenschaften'', Due to its distinctive tail spikes and plates, ''Stegosaurus'' is one of the most recognisable dinosaurs, along with ''Tyrannosaurus'', ''Triceratops'', and ''Apatosaurus''. The name ''Stegosaurus'' means "roof-lizard" and is derived from the Greek , ''stegos-'' ("roof") and , ''-sauros'' ("lizard").^[1]
At least three species have been identified in the upper Morrison Formation and are known from the remains of about 80 individuals. They lived some 155 to 145 million years ago, in an environment and time dominated by the giant sauropods ''Diplodocus'', ''Camarasaurus'', and ''Apatosaurus''.
A large, heavily-built and herbivorous quadruped, ''Stegosaurus'' had a distinctive and unusual posture, with a heavily-arched back, short forelimbs, head held low to the ground and a stiffened tail held high in the air. Its array of plates and spikes have been the subject of much speculation. The spikes were most likely used for defence, while the plates have also been proposed as a defensive mechanism, as well as having display and thermoregulatory (heat control) functions. ''Stegosaurus'' was the largest of all the stegosaurians (bigger than genera such as ''Kentrosaurus'' and ''Huayangosaurus'') and, although roughly bus-sized, it nonetheless shared many anatomical features (including the tail spines and plates) with the other stegosaurian genera.

Contents

Description

Classification

Origins

Discovery and species

Valid species

''Nomina dubia'' (dubious names)

Reassigned species

Palaeobiology

"Second brain"

Plates

Thagomizer (tail spikes)

Diet

Popular culture

See also

Footnotes

External links

Description

Averaging around 9 metres (30 ft) long and 4 metres (14 ft) tall, the quadrupedal ''Stegosaurus'' is one of the most easily-identifiable dinosaurs, due to the distinctive double row of kite-shaped plates rising vertically along its arched back and the two pairs of long spikes extending horizontally near the end of its tail. Although a large-bodied animal, it was dwarfed by its contemporaries, the giant sauropods. Some form of armour appears to have been necessary, as it coexisted with large predatory theropod dinosaurs, such as the fearsome ''Allosaurus'' and ''Ceratosaurus''.
The hind feet each had three short toes, while each forefoot had five toes; only the inner two toes had a blunt hoof. All four limbs were supported by pads behind the toes.^[2] The forelimbs were much shorter than the stocky hindlimbs, which resulted in an unusual posture. The tail appears to have been held well clear of the ground, while the head of ''Stegosaurus'' was positioned relatively low down, probably no higher than 1 metre (3.3 ft) above the ground. The Upper Jurassic Morrison Formation: An Interdisciplinary Study. Part 1. Modern Geol., Carpenter K, , , , 1998,

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 skulls low position suggests that ''Stegosaurus'' may have been a browser of low-growing vegetation. This interpretation is supported by the absence of front teeth and their replacement by a horny beak or rhamphotheca. Stegosaurian teeth were small, triangular and flat wear facets show that they did grind their food. The inset placement in the jaws suggests that ''Stegosaurus'' had cheeks to keep food in their mouths while they chewed. The Evolution and Extinction of the Dinosaurs (2nd Edition), Fastovsky DE, Weishampel DB, , , Cambridge University Press, 2005, ISBN 0-521-81172-4
Despite the animal's overall size, the braincase of ''Stegosaurus'' was small, being no larger than that of a dog. A well preserved ''Stegosaurus'' braincase allowed Othniel Charles Marsh to obtain in the 1880s a cast of the brain cavity or endocast of the animal, which gave an indication of the brain size. The endocast showed that the brain was indeed very small, maybe the smallest among the dinosaurs. The fact that an animal weighing over 4.5 tonnes (5 US short tons) could have a brain of no more than 80 grams (2.8 oz) contributed to the popular old idea that dinosaurs were extremely stupid, an idea now largely rejected. The Dinosaur Heresies, Bakker RT, , , William Morrow, New York, 1986,
Most of the information known about ''Stegosaurus'' comes from the remains of mature animals; however more recently juvenile remains of ''Stegosaurus'' have been found. One sub-adult specimen, discovered in 1994 in Wyoming, is 4.6 metres (15 ft) long and 2 metres (7 ft) high, and is estimated to have weighed 2.3 tonnes (2.6 short tons) while alive. It is on display in the University of Wyoming Geological Museum.^[3] Even smaller skeletons, 210 centimetres (6.9 ft) long and 80 centimetres (2.6 ft) tall at the back, are on display at the Denver Museum of Nature & Science.

Classification

''Stegosaurus'' was the first-named genus of the family Stegosauridae. It is the type genus, that gives its name to the family. Stegosauridae is one of two families within the infraorder Stegosauria, with the other being Huayangosauridae. Stegosauria lies within the Thyreophora, or armoured dinosaurs, a suborder which also includes the more diverse ankylosaurs. The stegosaurs were a clade of animals similar in appearance, posture and shape, that mainly differed in their array of spikes and plates. Among the closest relatives to ''Stegosaurus'' are ''Wuerhosaurus'' from China and ''Kentrosaurus'' from east Africa.

Origins

The origin of ''Stegosaurus'' is uncertain, as few remains of basal stegosaurs and their ancestors are known. Recently, stegosaurids have been shown to be present in the lower Morrison Formation, existing several million years before the occurrence of ''Stegosaurus'' itself, with the discovery of the related ''Hesperosaurus'' from the early Kimmeridgian.^[4] The earliest stegosaurid (the genus ''Lexovisaurus'') is known from the Oxford Clay Formation of England and France, giving it an age of early to middle Callovian.
The earlier, and more basal genus ''Huayangosaurus'' from the Middle Jurassic of China (some 165 million years ago) predates ''Stegosaurus'' by 20 million years and is the only genus in the family Huayangosauridae. Earlier still is ''Scelidosaurus'', from Early Jurassic England, which lived approximately 190 million years ago. Interestingly, it possessed features of both stegosaurs and ankylosaurs. ''Emausaurus'' from Germany was another small quadruped, while ''Scutellosaurus'' from Arizona in the USA was an even earlier genus and was facultatively bipedal. These small, lightly-armoured dinosaurs were closely related to the direct ancestor of both stegosaurs and ankylosaurs. A trackway of a possible early armoured dinosaur, from around 195 million years ago, has been found in France.^[5]

Discovery and species

''Stegosaurus'', one of the many dinosaurs first collected and described in the Bone Wars, was originally named by Othniel Charles Marsh in 1877, A new order of extinct Reptilia (Stegosauria) from the Jurassic of the Rocky Mountains, Marsh OC, , , American Journal of Science, 1877 from remains recovered north of Morrison, Colorado. These first bones became the holotype of ''Stegosaurus armatus''. The basis for its scientific name, 'roof(ed) lizard' has been thought to have been Marsh's initial belief that the plates lay flat over the animal's back, overlapping like the shingles (tiles) on a roof. A wealth of ''Stegosaurus'' material was recovered over the next few years and Marsh published several papers on the genus. Initially, several species were described. However, many of these have since been considered to be invalid or synonymous with existing species, The Armored Dinosaurs, Carpenter K & Galton PM, , , Indiana University Press, 2001, ISBN 0-253-33964-2 leaving two well-known and one poorly-known species.

Valid species

''Stegosaurus armatus'', meaning "armoured roof lizard", was the first species to be found and is known from two partial skeletons, two partial skulls and at least thirty fragmentary individuals. A new order of extinct Reptilia (Stegosauria) from the Jurassic of the Rocky Mountains, Marsh OC, , , American Journal of Science, 1877 This species had four horizontal tail spikes and relatively small plates. At 9 metres (30 ft), it was the longest species within the genus ''Stegosaurus''.
''Stegosaurus stenops'', meaning "narrow-faced roof lizard", was named by Marsh in 1887, Principal characters of American Jurassic dinosaurs, part IX. The skull and dermal armour of ''Stegosaurus'', Marsh OC, , , American Journal of Science, 1887 with the holotype having been collected by Marshal Felch at Garden Park, north of Cañon City, Colorado, in 1886. This is the best-known species of ''Stegosaurus'', mainly because its remains include at least one complete articulated skeleton. It had large, broad plates and four tail spikes. ''Stegosaurus stenops'' is known from at least 50 partial skeletons of both adults and juveniles, one complete skull and four partial skulls. It was shorter than ''S. armatus'', at 7 metres (23 ft).
''Stegosaurus longispinus'', meaning "long-spined roof lizard", was named by Charles W. Gilmore Osteology of the armored Dinosauria in the United States National Museum, with special reference to the genus ''Stegosaurus'', Gilmore CW, , , Series: Smithsonian Institution. United States National Museum. Bulletin 89, 1914 and known from one partial skeleton, from the Morrison Formation in Wyoming. ''Stegosaurus longispinus'' was notable for its set of four unusually long tail spines. Some consider it a species of ''Kentrosaurus''. Like ''S. stenops'', it grew to 7 metres (23 ft) in length.

''Nomina dubia'' (dubious names)

''Stegosaurus ungulatus'', meaning "hoofed roof lizard", was named by Marsh in 1879, from remains recovered at Como Bluff, Wyoming.^[6] It is known from a few vertebrae and armour plates. It might be a juvenile form of ''S. armatus'', The Dinosauria (2nd Edition), Galton PM, Upchurch P, , , University of California Press, 2004, ISBN 0-520-24209-2 although the original material of ''S. armatus'' is yet to be fully described. The specimen discovered in Portugal and dating from the upper Kimmeridgian-lower Tithonian stage has been ascribed to this species.Escaso, F, Ortega, F., Dantas, P., Malafaia, E., Pimentel, N.L, Pereda-Suberbiola, X., Sanz, J.L., Kullberg, J.C., Kullberg, M.C., and Barriga, F. (2007). "New Evidence of Shared Dinosaur Across Upper Jurassic Proto-North Atlantic: ''Stegosaurus'' From Portugal." ''Naturwissenschaften'',
''Stegosaurus sulcatus'', meaning "furrowed roof lizard" was described by Marsh in 1887 based on a partial skeleton. Principal characters of American Jurassic dinosaurs, part IX. The skull and dermal armour of ''Stegosaurus'', Marsh OC, , , American Journal of Science, 1887 It is considered a synonym of ''S. armatus''. The Dinosauria (2nd Edition), Galton PM, Upchurch P, , , University of California Press, 2004, ISBN 0-520-24209-2 ''Stegosaurus duplex'', meaning "two plexus roof lizard" (in allusion to the greatly enlarged neural canal of the sacrum which Marsh characterized as a "posterior brain case"), is probably the same as ''S. armatus''. The Dinosauria (2nd Edition), Galton PM, Upchurch P, , , University of California Press, 2004, ISBN 0-520-24209-2 Although named by Marsh in 1887 (including the holotype specimen), the disarticulated bones were actually collected in 1879 by Edward Ashley at Como Bluff, Wyoming.
''Stegosaurus seeleyanus'', originally named ''Hypsirophus'', is probably the same as ''S. armatus''. ''Stegosaurus (Diracodon) laticeps'' was described by Marsh in 1881, from some jawbone fragments.^[7] Just as some consider ''S. stenops'' a species of ''Diracodon'', others consider ''Diracodon'' itself to be a species of ''Stegosaurus''. Bakker had resurrected ''D. laticeps'' in 1986, The Dinosaur Heresies, Bakker RT, , , William Morrow, New York, 1986, although others note that the material is non-diagnostic and likely synonymous with ''S. stenops''. The Armored Dinosaurs, Carpenter K & Galton PM, , , Indiana University Press, 2001, ISBN 0-253-33964-2
''Stegosaurus affinis'', described by Marsh in 1881, is only known from a pubis and is considered ''nomen dubium''. The Dinosauria (2nd Edition), Galton PM, Upchurch P, , , University of California Press, 2004, ISBN 0-520-24209-2 It is possibly synonymous with ''S. armatus''. Osteology of the armored Dinosauria in the United States National Museum, with special reference to the genus ''Stegosaurus'', Gilmore CW, , , Series: Smithsonian Institution. United States National Museum. Bulletin 89, 1914

Reassigned species

''Stegosaurus madagascariensis'' from Madagascar is known solely from teeth and was described by Piveteau in 1926. The teeth were variously attributed to a stegosaur, the theropod ''Majungasaurus'',^[8] a hadrosaur or even a crocodylian.
Other remains originally attributed to ''Stegosaurus'' are now considered to belong to different genera. This is the case for ''Stegosaurus marshi'', which was described by Lucas in 1901. It was renamed ''Hoplitosaurus'' in 1902. ''Stegosaurus priscus'', described by Nopcsa in 1911, is a synonym of ''Lexovisaurus''. The Dinosauria (2nd Edition), Galton PM, Upchurch P, , , University of California Press, 2004, ISBN 0-520-24209-2

Palaeobiology

''Stegosaurus'' was the largest stegosaur, reaching up to 12 meters (39 ft) in length and possibly weighing up to 5,000 kilograms (5.5 short tons). However, 7 to 9 metres was a more usual length.
Soon after its discovery, Marsh considered ''Stegosaurus'' to have been bipedal, due to its short forelimbs. Principal characters of American Jurassic dinosaurs, part III, Marsh OC, , , American Journal of Science, 1880 He had changed his mind however, by 1891, after considering the heavy build of the animal. Restoration of ''Stegosaurus'', Marsh OC, , , American Journal of Science, 1891
Although ''Stegosaurus'' is undoubtedly now considered to have been quadrupedal, there has been some discussion over whether it could have reared up on its hind legs, using its tail to form a tripod with its hind limbs and browsing for higher foliage. The Dinosauria (2nd Edition), Galton PM, Upchurch P, , , University of California Press, 2004, ISBN 0-520-24209-2 This has been proposed by Bakker^[9] The Dinosaur Heresies, Bakker RT, , , william Morrow, New York, 1986, and opposed by Carpenter. , Carpenter K, , , , 1998,
''Stegosaurus'' did have very short forelimbs, in relation to its hind legs. Furthermore, within the hindlimbs, the lower section (comprising the tibia and fibula) was short compared with the femur. This suggests that it couldn't walk very fast, as the stride of the back legs at speed would have overtaken the front legs, giving a maximum speed of 6–7 kilometres per hour (4–5 mi/hr). The Evolution and Extinction of the Dinosaurs (2nd Edition), Fastovsky DE, Weishampel DB, , , Cambridge University Press, 2005, ISBN 0-521-81172-4

"Second brain"

Soon after describing ''Stegosaurus'', Marsh noted a large canal in the hip region of the spinal cord, which could have accommodated a structure up to 20 times larger than the brain. This has led to the famous idea that dinosaurs like ''Stegosaurus'' had a 'second brain' in the tail, which may have been responsible for controlling reflexes in the rear portion of the body. It has also been suggested that this "brain" might have given a ''Stegosaurus'' a temporary boost when it was under threat from predators. The Evolution and Extinction of the Dinosaurs (2nd Edition), Fastovsky DE, Weishampel DB, , , Cambridge University Press, 2005, ISBN 0-521-81172-4 More recently, it has been argued that this space (also found in sauropods) may have been the location of a glycogen body, a structure in living birds whose function is not definitely known but which is postulated to facilitate the supply of glycogen to the animal's nervous system. Gross Spinal Anatomy and Limb Use in Living and Fossil Reptiles, Buchholz (née Giffin) EB, , , Paleobiology, 1990

Plates

The most recognizable features of ''Stegosaurus'' are its dermal plates, which consisted of 17 separate flat plates. These were highly modified ''osteoderms'' (bony-cored scales), similar to those seen in crocodiles and many lizards today. They were not directly attached to the animal's skeleton, instead arising from the skin. In the past, some palaeontologists, notably Robert Bakker, have speculated the plates may have been mobile to some degree, although others disagree. Growth and Function of ''Stegosaurus'' Plates, Buffrénil, , , Paleobiology, 1986 Bakker suggested that the plates were the bony cores of pointed horn-covered plates that a ''Stegosaurus'' could flip from one side to another in order to present a predator with an array of spikes and blades that would impede it from closing sufficiently to attack the ''Stegosaurus'' effectively. The plates would naturally sag to the sides of the ''Stegosaurus'', the length of the plates reflecting the width of the animal at that point along its spine. His reasoning for these plates to be covered in horn is that the surface fossilised plates have a resemblance to the bony cores of horns in other animals known or thought to bear horns, and his reasoning for the plates to be defensive in nature is that the plates had insufficient width for them to stand erect easily in such a manner as to be useful in display without continuous muscular effort. ''The Dinosaur Heresies'', Bakker, R, , , Penguin Books, 1986, The largest plates were found over the animal's hips and measured 60 centimetres (2 ft) wide and 60 centimetres tall. The arrangement of the plates has long been a subject of debate but most palaeontologists now agree that they formed a pair of alternating rows, one running down each side of the midline of the animal's back.
The function of the plates has been much debated. Initially thought of as some form of armour, Principal characters of American Jurassic dinosaurs, part III, Marsh OC, , , American Journal of Science, 1880 they appear to have been too fragile and ill-placed for defensive purposes, leaving the animal's sides unprotected. The Theory of sexual selection, Davitashvili L, , , Izdatel'stvo Akademia nauk SSSR, 1961, More recently, researchers have proposed that they may have helped to control the body temperature of the animal, Growth and Function of ''Stegosaurus'' Plates, Buffrénil, , , Paleobiology, 1986 in a similar way to the sails of the large carnivorous ''Spinosaurus'' or of the pelycosaur ''Dimetrodon'' (and the ears of modern elephants and jackrabbits). The plates had blood vessels running through grooves and air flowing around the plates would have cooled the blood.^[10] This theory has been seriously questioned,^[11] since the closest relative to the common plate-wielding species, ''Stegosaurus stenops'', had low surface area spikes instead of plates, implying that cooling was not important enough to require specialised structural formations such as plates.
Their large size suggests that the plates may have served to increase the apparent height of the animal, in order either to intimidate enemies Osteology of the armored Dinosauria in the United States National Museum, with special reference to the genus ''Stegosaurus'', Gilmore CW, , , Series: Smithsonian Institution. United States National Museum. Bulletin 89, 1914 or to impress other members of the same species, in some form of sexual display, The Theory of sexual selection, Davitashvili L, , , Izdatel'stvo Akademia nauk SSSR, 1961, although both male and female specimens seemed to have had them. A study published in 2005 supports the idea of their use in identification. Researchers believe this may be the function of other unique anatomical features, found in various dinosaur species.^[12] ''Stegosaurus stenops'' also had disk-shaped plates on its hips.
One of the major subjects of books and articles about ''Stegosaurus'' is the plate arrangement.^[13] The argument has been a major one in the history of dinosaur reconstruction. Four possible plate arrangements have been mooted over the years:
#The plates lay flat along the back, like armour. This was Marsh's initial interpretation, which led to the name 'Roof Lizard'. As further and complete plates were found, their form showed that they stood on edge, rather than lying flat.
#By 1891, Marsh published a more familiar view of ''Stegosaurus'', Restoration of ''Stegosaurus'', Marsh OC, , , American Journal of Science, 1891 with a single row of plates. This was dropped fairly early on (apparently because it was poorly understood how the plates were embedded in the skin and it was thought that they would overlap too much in this arrangement). It was revived, in somewhat modified form, in the 1980s, by an artist (Stephen Czerkas),^[14] based on the arrangement of iguana dorsal spines.
#The plates paired in a double row along the back. This is probably the most common arrangement in pictures, especially earlier ones (until the 'Dinosaur Renaissance' in the '70s). (The ''Stegosaurus'' in the 1933 film, ''King Kong'' has this arrangement.) However, no two plates of identical size and shape have ever been found within the same animal.
#Two rows of alternating plates. By the early 1960s, this had become (and remains) the prevalent idea, mainly because the one ''Stegosaurus'' fossil with the plates still articulated indicates this arrangement. An objection to it is that this phenomenon is unknown among other reptiles and it is difficult to understand how such a disparity could evolve.

Thagomizer (tail spikes)

Main articles: Thagomizer

There has been debate about whether the tail spikes were used for display only, as posited by Gilmore in 1914 Osteology of the armored Dinosauria in the United States National Museum, with special reference to the genus ''Stegosaurus'', Gilmore CW, , , Series: Smithsonian Institution. United States National Museum. Bulletin 89, 1914 or used as a weapon. Robert Bakker noted the tail was likely to have been much more flexible than that of other dinosaurs, as it lacked ossified tendons, thus lending credence to the idea of the tail as a weapon. However, as Carpenter The Upper Jurassic Morrison Formation: An Interdisciplinary Study. Part 1. Modern Geol., Carpenter K, , , , 1998, has noted, the plates overlap so many tail vertebrae, that movement would be limited. Bakker also observed that ''Stegosaurus'' could have manoeuvred its rear easily, by keeping its large hindlimbs stationary and pushing off with its very powerfully muscled but short forelimbs, allowing it to swivel deftly to deal with attack. The Dinosaur Heresies, Bakker RT, , , william Morrow, New York, 1986, More recently, a study of tail spikes by McWhinney ''et al.'',^[15] which showed a high incidence of trauma-related damage, confirms the spikes were indeed used in combat. Additional support for this idea was a punctured tail vertebra of ''Allosaurus'' into which a tail spike fit perfectly.^[16]
''Stegosaurus stenops'' had four dermal spikes, each about 60–90 centimetres (2–3 ft) long. Discoveries of articulated stegosaur armour show that, at least in some species, these spikes protruded horizontally from the tail, not vertically as is often depicted. Initially, Marsh described ''S. armatus'' as having eight spikes in its tail, unlike ''S. stenops''. However, recent research re-examined this and concluded this species also had four. The Armored Dinosaurs, Carpenter K & Galton PM, , , Indiana University Press, 2001, ISBN 0-253-33964-2

Diet

''Stegosaurus'' and related genera were herbivores. However, they adopted a feeding strategy different from that of the other herbivorous ornithischian dinosaurs. The other ornithischians possessed teeth capable of grinding plant material and a jaw structure capable of movements in planes other than simply orthal (i.e they could chew plants). This contrasts with ''Stegosaurus'' (and all stegosaurians), which had small teeth having horizontal wear facets associated with tooth-food contact^[17] and a jaw probably capable of only orthal movements. The Dinosauria (2nd Edition, Galton PM, Upchurch P, , , University of California Press, 2004, ISBN 0-520-24209-2
The stegosaurians must have been successful, as they became speciose and geographically widely distributed, in the late Jurassic. The Dinosauria (2nd Edition, Galton PM, Upchurch P, , , University of California Press, 2004, ISBN 0-520-24209-2 Palaeontologists believe it would have eaten plants such as mosses, ferns, horsetails, cycads and conifers or fruits^[18] and swallowed gastroliths to aid food processing (due to the lack of chewing ability), in the same manner used by modern birds and crocodiles.^[19] Low-level browsing on grasses, seen in modern mammalian herbivores, would not have been possible for ''Stegosaurus'', as grasses did not evolve until late into the Cretaceous Period, long after ''Stegosaurus'' had become extinct.
One hypothesised feeding behaviour strategy considers them to be low-level browsers, eating low-growing fruit of various non-flowering plants, as well as foliage. This scenario has ''Stegosaurus'' foraging at most one metre above the ground. Interactions between Mesozoic Plants and Vertebrates:Fructifications and seed predation, Weishampel DB, , , N. Jb. Geol. Paläontol. Abhandl., 1984 On the other hand, if ''Stegosaurus'' could have raised itself on two legs, as suggested by Bakker, then it could have browsed on vegetation and fruits quite high up, with adults being able to forage up to 6 metres (20 ft) above the ground. The Evolution and Extinction of the Dinosaurs (2nd Edition), Fastovsky DE, Weishampel DB, , , Cambridge University Press, 2005, ISBN 0-521-81172-4

Popular culture

Main articles: Stegosaurus in popular culture


One of the most recognizable of all dinosaurs, ''Stegosaurus'' has been depicted on film, in cartoons, comics, as children's toys, and has even been declared the State Dinosaur of Colorado in 1982.^[20]

See also

★ Dinosaur

★ Othniel Charles Marsh

★ Stegosauria

★ Thagomizer

★ Thyreophora

Footnotes

1. Greek-English Lexicon, Abridged Edition, Liddell & Scott, , , Oxford University Press, Oxford, UK, 1980, ISBN 0-19-910207-4
2. The Ultimate Dinosaur Book, Lambert D, , , Dorling Kindersley, New York, 1993, ISBN 1-56458-304-X
3. ''Stegosaurus''. University of Wyoming Geological Museum. 2006. Retrieved October 6 2006. University of Wyoming Geological Museum
4. The Armored Dinosaurs, Carpenter K, Miles CA, Cloward K, , , Indiana University Press, 2001, ISBN 0-253-33964-2
5. Le Loeuff J, Lockley M, Meyer C, Petit J-P(1999) Discovery of a thyreophoran trackway in the Hettangian of central France. ''C. R. Acad. Sci. Paris'' '2' 328, 215–219
6. Notice of new Jurassic reptiles, Marsh OC, , , American Journal of Science, 1879
7. Principal characters of American Jurassic dinosaurs, part V, Marsh OC, , , American Journal of Science, 1881
8. Galton PM (1981) "Craterosaurus pottonensis Seeley, a stegosaurian dinosaur from the Lower Cretaceous of England, and a review of Cretaceous stegosaurs". Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen 161(1):28–46
9. Dinosaur feeding behavior and the origin of flowering plants, Bakker RT, , , Nature, 1978
10. Plates of the dinosaur ''Stegosaurus'':Forced convection heat loss fins?, Farlow JO, Thompson CV, Rosner DE, , , Science, 1976
11. Comparative histology, growth and evolution of archosaurian osteoderms: why did ''Stegosaurus'' have such large dorsal plates?, Main RP, Padian K, Horner J, , , Journal of Vertebrate Paleontology 56A, 2000
12. "Stegosaur plates used for identification"
13. Dinosaurs: Their Discovery & Their World, Colbert EH, , , Hutchinson Press, London, 1962, ISBN 1-111-21503-0
14. Dinosaurs Past & Present, Vol 2, Czerkas SA, , , University of Washington Press, Seattle, 1987, ISBN
15. The Armored Dinosaurs, McWhinney LA, Rothschild BM & Carpenter K, , , Indiana University Press, 2001, ISBN 0-253-33964-2
16. The Carnivorous Dinosaurs, Carpenter K, Sanders F., McWhiiney L.& Wood L, , , Indiana University Press, 2005, ISBN 0-253-34539-1
17. The Armored Dinosaurs, Barrett PM, , , Indiana University Press, 2001, ISBN 0-253-33964-2
18. ''Stegosaurus ungulatus'' Carnegie Museum of Natural History. Retrieved 26 October 2006.
19. Stegosaurs Jacobson, RJ. Dinosaur and Vertebrate Paleontology Information. Retrieved 26 October 2006.
20. Colorado Department of Personnel website - State emblems

External links

★ Walking With Dinosaurs - ''Stegosaurus''

★ Europe's First Stegosaurus Boosts Pangaea Theory