Stegosaurus Fossil range: Late Jurassic
Model Stegosaurus, Bałtów Jurassic Park, Poland.
Scientific classification
Kingdom: Animalia Phylum: Chordata Class: Sauropsida Superorder: Dinosauria Order: Ornithischia Suborder: Thyreophora Infraorder: Stegosauria Family: Stegosauridae Genus: Stegosaurus Marsh, 1877
Species
S. armatus Marsh, 1877 (type) S. stenops Marsh, 1887 S. longispinus Gilmore, 1914

Stegosaurus (IPA: /ˌstɛgəˈsɔrəs/) 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.^[1] Due to its distinctive tail spikes and plates, Stegosaurus is one of the most recognizable dinosaurs, along with Tyrannosaurus, Triceratops, and Apatosaurus. The name Stegosaurus means "roof-lizard" and is derived from the Greek στέγος-, stegos- ("roof") and σαῦρος, -sauros ("lizard").^[2] 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. Upper Jurassic (also known as Malm) was an epoch of the Jurassic geologic period. ... Image File history File linksMetadata Download high-resolution version (2060x1548, 1249 KB) NOTE: THIS PHOTOGRAPH DEPICTS A PRESUMABLY COPYRIGHTED SCULPTURE, AND SO IS A DERIVATIVE OF THAT WORK. SOURCE INFORMATION FOR THAT SCULPTURE MUST BE PROVIDED, AND EITHER A LICENSE OR FAIR USE JUSTIFICATION TO MAKE USE OF IT IN... Scientific classification or biological classification refers to how biologists group and categorize extinct and living species of organisms. ... For other uses, see Animal (disambiguation). ... Typical Classes See below Chordates (phylum Chordata) are a group of animals that includes the vertebrates, together with several closely related invertebrates. ... Reptilia redirects here. ... Orders & Suborders Saurischia Sauropodomorpha Theropoda Ornithischia Thyreophora Ornithopoda Marginocephalia Dinosaurs were vertebrate animals that dominated the terrestrial ecosystem for over 160 million years, first appearing approximately 230 million years ago. ... Suborders Thyreophora Cerapoda    Ornithopoda    Marginocephalia Ornithischia is an order of beaked, herbivorous dinosaurs. ... Clades Tatisaurus Scutellosaurus Emausaurus Eurypoda Ankylosauria Stegosauria The Thyreophora (shield bearers, often known simply as armored dinosaurs - Greek: θυρεος, a large oblong shield, like a door and φορεω, I carry) were a subgroup of the ornithischian dinosaurs. ... Families Huayangosauridae Stegosauridae Stegosauria is a superfamily of Thyreophora. ... Stegosauridae is a family of armored dinosaurs in the infraorder Stegosauria. ... Othniel Charles Marsh (1831-1899) Othniel Charles Marsh (October 29, 1831 - March 18, 1899) was one of the pre-eminent paleontologists of the 19th century, who discovered and named many fossils found in the American West. ... For other uses, see Species (disambiguation). ... A type species fixes the name of a genus (or of a taxon in a rank lower than genus). ... Charles Whitney Gilmore (1874-1945) was an American paleontologist, who named dinosaurs in North America and Mongolia, including the Cretaceous sauropod Alamosaurus, Alectrosaurus, Archaeornithomimus, Bactrosaurus, Brachyceratops, Chirostenotes, Mongolosaurus, Parrosaurus, Pinacosaurus, Styracosaurus and Thescelosaurus. ... For other uses, see Genus (disambiguation). ... Families Huayangosauridae Stegosauridae Stegosauria is a superfamily of Thyreophora. ... Clades Tatisaurus Scutellosaurus Emausaurus Eurypoda Ankylosauria Stegosauria The Thyreophora (shield bearers, often known simply as armored dinosaurs - Greek: θυρεος, a large oblong shield, like a door and φορεω, I carry) were a subgroup of the ornithischian dinosaurs. ... Orders & Suborders Saurischia Sauropodomorpha Theropoda Ornithischia Thyreophora Ornithopoda Marginocephalia Dinosaurs were vertebrate animals that dominated the terrestrial ecosystem for over 160 million years, first appearing approximately 230 million years ago. ... Upper Jurassic (also known as Malm) was an epoch of the Jurassic geologic period. ... A geologic period is a subdivision of geologic time that divides an era into smaller timeframes. ... The Kimmeridgian is a stage of the Late Jurassic Epoch. ... The Tithonian (141-135 MYA) is the most recent faunal stage of the Jurassic era. ... North American redirects here. ... Now this end is called the thagomizer, after the late Thag Simmons. ... Species T. rex (type) Osborn, 1905 Synonyms Manospondylus Cope, 1892 Dynamosaurus Osborn, 1905  ?Nanotyrannus Bakker, Williams & Currie, 1988 Stygivenator Olshevsky, 1995 Dinotyrannus Olshevsky, 1995 Tyrannosaurus (pronounced IPA: , meaning tyrant lizard) is a genus of theropod dinosaur. ... Species (type) Marsh, 1890 Triceratops (IPA: ) was a herbivorous genus of ceratopsid dinosaur that lived during the late Maastrichtian stage of the Late Cretaceous Period, around 68 to 65 million years ago (mya) in what is now North America. ... Species Apatosaurus ajax Apatosaurus excelsus Apatosaurus louisae Apatosaurus (pronounced ) meaning deceptive lizard, because its chevron bones were like those of Mosasaurus (Greek apatelos or apatelios = deceptive + sauros = lizard), often mistakenly referred to as Brontosaurus, is a genus of sauropod dinosaurs that lived about 140 million years ago, during the Jurassic... The Morrison Formation is a distinctive body of rock in the western United States and Canada that has been the most fertile source of fossils in North America. ... For other uses of mya, see mya (disambiguation). ... Families Brachiosauridae Camarasauridae Cetiosauridae Diplodocidae Euhelopodidae Nemegtosauridae Titanosauridae Vulcanodontidae Sauropoda, the sauropods, are a suborder or infraorder of the saurischian (lizard-hipped) dinosaurs. ... For the extinct amphibian, see Diplocaulus. ... Species (holotype) The Camarasaurus (pronounced KAM-a-rah-SORE-us) was a genera of quadrupedal, herbivorous dinosaurs. ... Species Apatosaurus ajax Apatosaurus excelsus Apatosaurus louisae Apatosaurus (pronounced ) meaning deceptive lizard, because its chevron bones were like those of Mosasaurus (Greek apatelos or apatelios = deceptive + sauros = lizard), often mistakenly referred to as Brontosaurus, is a genus of sauropod dinosaurs that lived about 140 million years ago, during the Jurassic...

A large, heavily built, 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 defense, 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. A deer and two fawns feeding on some foliage A herbivore is often defined as any organism that eats only plants[1]. By that definition, many fungi, some bacteria, many animals, about 1% of flowering plants and some protists can be considered herbivores. ... The Zebra is an example of a quadruped. ... Thermoregulation is the ability of an organism to keep its body temperature within certain boundaries, even when temperature surrounding is very different. ... Families Huayangosauridae Stegosauridae Stegosauria is a superfamily of Thyreophora. ... Species (type) Kentrosaurus aethiopica (pointed lizard from Africa) was a genus of dinosaur closely related to the better-known Stegosaurus. ... This article does not cite its references or sources. ...

Description

The size of a Stegosaurus compared to a human.

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 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. Wikipedia does not have an article with this exact name. ... Wikipedia does not have an article with this exact name. ... metre or meter, see meter (disambiguation) The metre is the basic unit of length in the International System of Units. ... A foot (plural: feet or foot;[1] symbol or abbreviation: ft or, sometimes, ′ – a prime) is a unit of length, in a number of different systems, including English units, Imperial units, and United States customary units. ... Families Brachiosauridae Camarasauridae Cetiosauridae Diplodocidae Euhelopodidae Nemegtosauridae Titanosauridae Vulcanodontidae Sauropoda, the sauropods, are a suborder or infraorder of the saurischian (lizard-hipped) dinosaurs. ... Armour in animals is external or superficial protection against attack by predators, formed as part of the body (rather than the behavioural use of protective external objects), usually through the hardening of body tissues, outgrowths or secretions. ... Species type (Marsh, 1878) Paul, 1987 Mateus , 2006 jimmadseni Chure, 2000 vide Glut, 2003 Synonyms Creosaurus Marsh, 1878 Labrosaurus Marsh, 1879 Camptonotus Marsh, 1879  ?Epanterias Cope, 1878 Allosaurus (IPA: ) was a large (up to 11. ... Species (type) Marsh, 1884 (Janensch, 1920) Madsen & Wells, 2000 Madsen & Wells, 2000 Ceratosaurus (IPA: ) meaning horned lizard, in reference to the horn on its nose (Greek keras/keratos meaning horn and sauros meaning lizard), was a large predatory dinosaur from the Late Jurassic Period, found in the Morrison Formation of...

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.^[3] 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.^[4]

Stegosaurus skull.

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 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.^[5] For other uses of Skull, see Skull (disambiguation). ... An antorbital fenestra is an opening in the skull, in front of the eye socket. ... Clades Crurotarsi Aetosauria Crocodilia (crocodiles) Phytosauria Rauisuchia Ornithodira Aves (birds) Dinosauria Pterosauria Archosaurs (Greek for ruling lizards) are a group of diapsid reptiles that is represented today by birds and crocodiles and which also included the dinosaurs. ... The beak, bill or rostrum is an external anatomical structure of birds which, in addition to eating, is used for grooming, manipulating objects, killing prey, probing for food, courtship, and feeding their young. ...

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.^[6] Othniel Charles Marsh (1831-1899) Othniel Charles Marsh (October 29, 1831 - March 18, 1899) was one of the pre-eminent paleontologists of the 19th century, who discovered and named many fossils found in the American West. ... A tonne (also called metric ton) is a non-SI unit of mass, accepted for use with SI, defined as: 1 tonne = 103 kg (= 106 g). ... The short ton is a unit of mass equal to 2000 lb (exactly 907. ... For other meanings of gram, see gram (disambiguation). ... This article is about Ounce (unit of mass). ...

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.^[7] 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

Life restoration of Stegosaurus stenops.

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. Stegosauridae is a family of armored dinosaurs in the infraorder Stegosauria. ... Type specimens When a new species is discovered, more important than creating a new and unique name for the species is developing a reasonably detailed description. ... Families Huayangosauridae Stegosauridae Stegosauria is a superfamily of Thyreophora. ... The Huayangosauridae were an early family of Stegosaurs which includes the Huayangosaurus. ... Clades Tatisaurus Scutellosaurus Emausaurus Eurypoda Ankylosauria Stegosauria The Thyreophora (shield bearers, often known simply as armored dinosaurs - Greek: θυρεος, a large oblong shield, like a door and φορεω, I carry) were a subgroup of the ornithischian dinosaurs. ... Armour in animals is external or superficial protection against attack by predators, formed as part of the body (rather than the behavioural use of protective external objects), usually through the hardening of body tissues, outgrowths or secretions. ... Families Nodosauridae Ankylosauridae Ankylosauria is an infraorder of the suborder Thyreophora. ... A clade is a term belonging to the discipline of cladistics. ... Wuerhosaurus was a Chinese stegosaur from Late Jurassic times. ... Species (type) Kentrosaurus aethiopica (pointed lizard from Africa) was a genus of dinosaur closely related to the better-known Stegosaurus. ...  Eastern Africa (UN subregion)  East African Community  Central African Federation (defunct)  Geographic East Africa, including the UN subregion and East African Community East Africa or Eastern Africa is the easternmost region of the African continent, variably defined by geography or geopolitics. ...

Origins

Reconstruction of a Stegosaurus skeleton in the Senckenberg Museum in Frankfurt.

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.^[8] 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. T. Rex The Senckenberg Museum in Frankfurt is the largest museum of natural history in Germany. ... For other uses, see Frankfurt (disambiguation). ... Species The Hesperosaurus was a herbivorous dinosaur from the Kimmeridgian to Tithonian epochs of the Jurassic period (approximately 150 million years ago), whose fossils are found in the state of Wyoming in the United States of America. ... The Kimmeridgian is a stage of the Late Jurassic Epoch. ... Lexovisaurus was a stegosaur from Late Jurassic Europe, 165 mya. ... Oxford Clay is a Jurassic marine sedimentary rock underlying much of South East England from as far West as Dorset and as far North as Yorkshire. ... For other uses, see England (disambiguation). ... The Callovian is a stage on the geologic time scale occuring from 164. ...

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.^[9] This article does not cite its references or sources. ... Scelidosaurus (meaning limb lizard) was a heavily plated, plant-eating dinosaur. ... For other uses, see England (disambiguation). ... Species Emausaurus ernsti (type) Emausaurus is the name given to a genus of dinosaur from the Early Jurassic. ... Species Scutellosaurus (little-shielded lizard) is a genus of herbivorous dinosaur that lived in North America around 208 to 220 million years ago, in the Early Jurassic. ... Official language(s) English Spoken language(s) English 74. ...

Discovery and species

Marsh's 1896 illustration of Stegosaurus. Note the twelve dorsal plates and eight tail spikes; Stegosaurus actually had 17 plates and just four spikes.

Stegosaurus, one of the many dinosaurs first collected and described in the Bone Wars, was originally named by Othniel Charles Marsh in 1877,^[10] 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,^[11] leaving two well-known and one poorly-known species. Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ... Bone Wars - Wikipedia /**/ @import /w/skins-1. ... Othniel Charles Marsh (1831-1899) Othniel Charles Marsh (October 29, 1831 - March 18, 1899) was one of the pre-eminent paleontologists of the 19th century, who discovered and named many fossils found in the American West. ... Morrison is a town in Jefferson County, Colorado, in the United States. ... A holotype is one of several possible types. ... Latin name redirects here. ... The largest (6000 m²) wooden shingle roof in Europe: Zakopane, Poland Roof shingles are a roof covering consisting of individual overlapping elements. ... Mission, or barrel, roof tiles A tile is a manufactured piece of hard-wearing material such as ceramic, stone, porcelain, metal or even glass. ...

Valid species

Front view of a Stegosaurus skeleton at the National Museum of Natural History.

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.^[10] 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,^[12] 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). A holotype is one of several possible types. ... “Canon City” redirects here. ... Official language(s) English Demonym Coloradan Capital Denver Largest city Denver Largest metro area Denver-Aurora Metro Area Area  Ranked 8th in the US  - Total 104,185 sq mi (269,837 km²)  - Width 280 miles (451 km)  - Length 380 miles (612 km)  - % water 0. ...

Stegosaurus longispinus, meaning "long-spined roof lizard", was named by Charles W. Gilmore^[13] 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. Charles Whitney Gilmore (1874-1945) was an American paleontologist, who named dinosaurs in North America and Mongolia, including the Cretaceous sauropod Alamosaurus, Alectrosaurus, Archaeornithomimus, Bactrosaurus, Brachyceratops, Chirostenotes, Mongolosaurus, Parrosaurus, Pinacosaurus, Styracosaurus and Thescelosaurus. ... The Morrison Formation is a distinctive body of rock in the western United States and Canada that has been the most fertile source of fossils in North America. ... Official language(s) English Capital Cheyenne Largest city Cheyenne Area  Ranked 10th  - Total 97,818 sq mi (253,348 km²)  - Width 280 miles (450 km)  - Length 360 miles (580 km)  - % water 0. ... Species (type) Kentrosaurus aethiopica (pointed lizard from Africa) was a genus of dinosaur closely related to the better-known Stegosaurus. ...

Nomina dubia (dubious names)

strata at Como Bluff

Stegosaurus ungulatus, meaning "hoofed roof lizard", was named by Marsh in 1879, from remains recovered at Como Bluff, Wyoming.^[14] It is known from a few vertebrae and armour plates. It might be a juvenile form of S. armatus,^[15] 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.^[1] Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ... Como Bluff is a long ridge extending east-west, located about 6 miles between the towns of Rock River and Medicine Bow, Wyoming. ... Como Bluff is a long ridge extending east-west, located about 6 miles between the towns of Rock River and Medicine Bow, Wyoming. ... Official language(s) English Capital Cheyenne Largest city Cheyenne Area  Ranked 10th  - Total 97,818 sq mi (253,348 km²)  - Width 280 miles (450 km)  - Length 360 miles (580 km)  - % water 0. ... A diagram of a thoracic vertebra. ... Armour in animals is external or superficial protection against attack by predators, formed as part of the body (rather than the behavioural use of protective external objects), usually through the hardening of body tissues, outgrowths or secretions. ... The Kimmeridgian is a stage of the Late Jurassic Epoch. ... The Tithonian (141-135 MYA) is the most recent faunal stage of the Jurassic era. ...

Stegosaurus sulcatus, meaning "furrowed roof lizard" was described by Marsh in 1887 based on a partial skeleton.^[12] It is considered a synonym of S. armatus.^[15] 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.^[15] 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. A holotype is one of several possible types. ... Como Bluff is a long ridge extending east-west, located about 6 miles between the towns of Rock River and Medicine Bow, Wyoming. ... Official language(s) English Capital Cheyenne Largest city Cheyenne Area  Ranked 10th  - Total 97,818 sq mi (253,348 km²)  - Width 280 miles (450 km)  - Length 360 miles (580 km)  - % water 0. ...

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.^[16] 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,^[17] although others note that the material is non-diagnostic and likely synonymous with S. stenops.^[11] Robert T. Bakker (Bob Bakker), born in Bergen, New Jersey, 1945, is a famous American paleontologist who has helped re-shape modern theories about dinosaurs, particularly by adding support to the theory that some dinosaurs were homeothermic (warm-blooded). ...

Stegosaurus affinis, described by Marsh in 1881, is only known from a pubis and is considered a nomen dubium.^[15] It is possibly synonymous with S. armatus.^[13] The pubis, the anterior part of the hip bone, is divisible into a body, a superior and an inferior ramus. ... In scientific classification, a nomen dubium (Latin for doubtful name, plural nomina dubia) is a scientific name that is valid but of unknown or doubtful application: that is, it may be impossible to determine whether a specimen belongs to that group or not. ...

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,^[18] a hadrosaur or even a crocodylian. Majungatholis is the name given to a genus of dinosaur from the Late Cretaceous. ... Hadrosaurus foulkii is a hadrosaurid dinosaur species, and the first full dinosaur skeleton found in North America. ... Subfamilies Family Crocodylidae    Crocodylinae    Alligatorinae    Gavialinae Crocodylia is an order of large reptiles that scientists believe branched off from class Reptilia about 220 million years ago. ...

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.^[15] Binomial name Lucas, 1902 Hoplitosaurus (meaning Hoplite lizard) was a genus of armored dinosaur related to Polacanthus. ... Lexovisaurus was a stegosaur from Late Jurassic Europe, 165 mya. ...

Palaeobiology

Animatronic Stegosaurus, Experimentarium, Copenhagen.

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.^[19] He had changed his mind however, by 1891, after considering the heavy build of the animal.^[12] 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.^[15] This has been proposed by Bakker^[20][17] and opposed by Carpenter.^[4] Image File history File linksMetadata Size of this preview: 800 × 562 pixelsFull resolution (1114 × 783 pixel, file size: 145 KB, MIME type: image/jpeg) Animatronic Stegosaurus. ... Image File history File linksMetadata Size of this preview: 800 × 562 pixelsFull resolution (1114 × 783 pixel, file size: 145 KB, MIME type: image/jpeg) Animatronic Stegosaurus. ... Animatronic is the third album from Norweigan black metal band, The Kovenant, and was released in 1999 through Nuclear Blast. ... Families Huayangosauridae Stegosauridae Stegosauria is a superfamily of Thyreophora. ... Robert T. Bakker (Bob Bakker), born in Bergen, New Jersey, 1945, is a famous American paleontologist who has helped re-shape modern theories about dinosaurs, particularly by adding support to the theory that some dinosaurs were homeothermic (warm-blooded). ... Kenneth Carpenter is a Paleontologist at the Denver Museum of Natural History and author or co-author of a number of books on dinosaurs and Mesozoic life. ...

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).^[5] This article is about the vertebrate bone. ... For other uses see fibula (disambiguation) The fibula or calf bone is a bone placed on the lateral side of the tibia, with which it is connected above and below. ... The femur or thigh bone is the longest, most voluminous, and strongest bone of the mammalian bodies. ...

"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.^[5] 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.^[21] Families Brachiosauridae Camarasauridae Cetiosauridae Diplodocidae Euhelopodidae Nemegtosauridae Titanosauridae Vulcanodontidae Sauropoda, the sauropods, are a suborder or infraorder of the saurischian (lizard-hipped) dinosaurs. ... Glycogen Structure Segment Glycogen is a polysaccharide of glucose (Glc) which functions as the primary short term energy storage in animal cells. ... The nervous system is a highly specialized network whose principal components are nerves called neurons. ...

Plates

Stegosaurus skeleton, Field Museum, Chicago.

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.^[22] 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.^[23] 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. Field Museum of Natural History, Chicago The Field Museum of Natural History, in Chicago, Illinois, USA, sits on Lake Shore Drive next to Lake Michigan, part of a scenic complex called known as the Museum Campus which includes Soldier Field, the football stadium that is the home of the Chicago... For other uses, see Chicago (disambiguation). ... Osteoderms are a bony deposit forming a scale, plate, or other structure in the dermal layers of the skin. ... Paleontology, palaeontology or palæontology (from Greek: paleo, ancient; ontos, being; and logos, knowledge) is the study of prehistoric life forms on Earth through the examination of plant and animal fossils. ... Robert T. Bakker (Bob Bakker), born in Bergen, New Jersey, 1945, is a famous American paleontologist who has helped re-shape modern theories about dinosaurs, particularly by adding support to the theory that some dinosaurs were homeothermic (warm-blooded). ... cm redirects here, alternate uses: cm (disambiguation) A centimetre (symbol cm; American spelling: centimeter) is an SI unit of length. ...

Scutes, plates and skull of Stegosaurus, Denver Museum.

The function of the plates has been much debated. Initially thought of as some form of armour,^[19] they appear to have been too fragile and ill-placed for defensive purposes, leaving the animal's sides unprotected.^[24] More recently, researchers have proposed that they may have helped to control the body temperature of the animal,^[22] 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.^[25] This theory has been seriously questioned,^[26] 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. Species Stromer, 1915 (type) ? Russell, 1996 Spinosaurus (meaning spine lizard) is a genus of theropod dinosaur which lived in what is now North Africa, from the Albian to early Cenomanian stages of the Cretaceous Period, about 100 to 93 million years ago. ... Groups see text The pelycosaurs (from Greek pelyx meaning bowl and sauros meaning lizard) were primitive Late Paleozoic synapsid amniotes. ... Species Dimetrodon grandis skeleton at the National Museum of Natural History Dimetrodon () (two measures of teeth), was a predatory synapsid (mammal-like reptile) genus that flourished during the Permian Period, living between 280 and 265 million years ago. ... Area is the measure of how much exposed area any two dimensional object has. ...

Their large size suggests that the plates may have served to increase the apparent height of the animal, in order either to intimidate enemies^[13] or to impress other members of the same species, in some form of sexual display,^[24] 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.^[27] Stegosaurus stenops also had disk-shaped plates on its hips. Display is a form of animal behaviour, linked to survival of the species in various ways. ...

One of the major subjects of books and articles about Stegosaurus is the plate arrangement.^[28] The argument has been a major one in the history of dinosaur reconstruction. Four possible plate arrangements have been mooted over the years:

Early reconstruction of Stegosaurus with plates paired in a double row and eight tail spikes.

1. 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.
2. By 1891, Marsh published a more familiar view of Stegosaurus,^[12] 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),^[29] based on the arrangement of iguana dorsal spines.
3. 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.
4. 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.

For other members of the family Iguanidae, see Iguanidae. ... This article or section does not adequately cite its references or sources. ... For other uses, see King Kong (disambiguation). ...

Thagomizer (tail spikes)

Main article: Thagomizer

Thagomizer on mounted Stegosaurus tail.

There has been debate about whether the tail spikes were used for display only, as posited by Gilmore in 1914^[13] 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^[4] has noted, the plates overlap so many tail vertebrae, that movement would be limited. Bakker also observed that Stegosaurus could have maneuvered 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.^[17] More recently, a study of tail spikes by McWhinney et al.,^[30] 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.^[31] Now this end is called the thagomizer, after the late Thag Simmons. ...

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.^[11]

Diet

Stegosaurus tooth.

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^[32] and a jaw probably capable of only orthal movements.^[15] Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ... Suborders Thyreophora Cerapoda    Ornithopoda    Marginocephalia Ornithischia is an order of beaked, herbivorous dinosaurs. ...

The stegosaurians must have been successful, as they became speciose and geographically widely distributed, in the late Jurassic.^[15] Palaeontologists believe it would have eaten plants such as mosses, ferns, horsetails, cycads and conifers or fruits^[33] and swallowed gastroliths to aid food processing (due to the lack of chewing ability), in the same manner used by modern birds and crocodiles.^[34] 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. Gastroliths (stomach stones or gizzard stones) are rocks, which are or have been held inside the digestive tract of an animal. ... Subclasses & Infraclasses Subclass †Allotheria* Subclass Prototheria Subclass Theria Infraclass †Trituberculata Infraclass Metatheria Infraclass Eutheria For the folk-rock band see The Mammals. ... The Cretaceous period is one of the major divisions of the geologic timescale, reaching from the end of the Jurassic period (about 135 mya) to the beginning of the Paleocene epoch of the Tertiary period (65 mya). ...

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.^[35] 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.^[5]

Popular culture

Main article: Cultural depictions of Stegosaurus

Animatronic juvenile Stegosaurus, Tivoli, Copenhagen.

One of the most recognizable of all dinosaurs,^[5] 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.^[36] Model Stegosaurus, BaÅ‚tów Jurassic Park, Poland. ... Image File history File linksMetadata Size of this preview: 749 × 600 pixelsFull resolution (844 × 676 pixel, file size: 84 KB, MIME type: image/jpeg) Juvenile Stegosaurus. ... Image File history File linksMetadata Size of this preview: 749 × 600 pixelsFull resolution (844 × 676 pixel, file size: 84 KB, MIME type: image/jpeg) Juvenile Stegosaurus. ... Animatronic is the third album from Norweigan black metal band, The Kovenant, and was released in 1999 through Nuclear Blast. ... It has been suggested that this article or section be merged into State fossil. ... Official language(s) English Demonym Coloradan Capital Denver Largest city Denver Largest metro area Denver-Aurora Metro Area Area  Ranked 8th in the US  - Total 104,185 sq mi (269,837 km²)  - Width 280 miles (451 km)  - Length 380 miles (612 km)  - % water 0. ...

See also

• Othniel Charles Marsh
• Thagomizer

Othniel Charles Marsh (1831-1899) Othniel Charles Marsh (October 29, 1831 - March 18, 1899) was one of the pre-eminent paleontologists of the 19th century, who discovered and named many fossils found in the American West. ... Now this end is called the thagomizer, after the late Thag Simmons. ...

Footnotes

is the 279th day of the year (280th in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 145th day of the year (146th in leap years) in the Gregorian calendar. ... Year 2005 (MMV) was a common year starting on Saturday (link displays full calendar) of the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 299th day of the year (300th in leap years) in the Gregorian calendar. ... Osteomyelitis is an infection of bone, usually caused by pyogenic bacteria or mycobacteria. ... is the 299th day of the year (300th in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 299th day of the year (300th in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ...

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