PBDB Taxon

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Stegosaurus

Reptilia - Stegosauridae

Taxonomy

Stegosaurus was named by Marsh (1877). It is the type genus of Stegosauridae, Stegosaurinae, Stegosauroidea.

It was synonymized subjectively with Hypsirophus by Lydekker (1893).

It was assigned to Sauroscelida by Williston (1878); to Stegosauria by Quenstedt (1882); to Stegosauria by Dollo (1885) and Marsh (1893); to Stegosauri by Gadow (1897); to Stegosauri by Gadow (1898) and Gadow (1901); to Stegosauria by Marsh (1877), Marsh (1887), Dollo (1889), Marsh (1892), Winkler (1893), Delair (1960) and Chure et al. (2006); to Stegosauridae by Marsh (1880), Marsh (1881), Sauvage (1882), Dollo (1884), Marsh (1884), Marsh (1885), Zittel (1890), Marsh (1895), Marsh (1896), Nopcsa (1901), Mansel-Pleydell (1902), Hay (1902), Huene (1909), von Zittel (1911), Tornier (1913), Gilmore (1914), Hennig (1915), Lambe (1918), Joleaud (1922), Lull (1924), Piveteau (1926), Hay (1930), Chakravarti (1934), Young (1959), Tatarinov (1964), Kuhn (1964), Romer (1966), Charig (1967), Swinton (1970), Galton (1977), Madsen and Miller (1979), Galton (1980), McIntosh (1981), Russell (1984), Bonaparte (1986), Sereno (1986), Carroll (1988), Galton (1990), Miller et al. (1991), Olshevsky and Ford (1993), Dodson (1997), Blows (2001), Galton and Upchurch (2004), Maidment et al. (2006), Escaso et al. (2007), Galton (2007), Mateus et al. (2009) and Mateus and Milàn (2010); and to Stegosaurinae by Nopcsa (1928), Romer (1956), Hoffstetter and Brun (1958), Dong et al. (1983), Zhou (1983), Zhou (1986), Sereno (1998), Escaso et al. (2007), Maidment et al. (2008) and Ulansky (2014).

Species

Diracodon laticeps, Hypsirophus discurus, Hypsirophus seeleyanus, S. affinis, S. armatus, S. armatus, S. duplex, S. stenops, S. sulcatus, S. ungulatus, Wuerhosaurus homheni

Synonyms

Wuerhosaurus was named by Dong (1973).

It was synonymized subjectively with Stegosaurus by Maidment et al. (2008) and Mateus et al. (2009).

It was assigned to Stegosauroidea by Zhao (1983); to Stegosauria by Olshevsky and Ford (1993); to Stegosaurinae by Dong et al. (1983), Zhou (1986), Dong (1990), Dong (1992) and Ulansky (2014); and to Stegosauridae by Dong (1973), Galton (1981), Sereno (1986), Carroll (1988), Galton (1990), Dong (1994), Carpenter et al. (2001), Blows (2001), Galton and Upchurch (2004) and Tumanova and Alifanov (2018).
Stegosaurus armatus was named by Marsh (1877). Its type specimen is BMNH 46013, a set of postcrania, and it is a 3D body fossil. Its type locality is Swindon Brick and Tile Company brick pit, which is in a Kimmeridgian marine claystone in the Kimmeridge Clay Formation of the United Kingdom.

It was considered a nomen dubium by Galton (2010); it was considered a nomen dubium by International Commission on Zoological Nomenclature (2013).
Diracodon was named by Marsh (1881). Its type is Diracodon laticeps.

It was synonymized subjectively with Stegosaurus by Hennig (1915), Romer (1956), Tatarinov (1964), Kuhn (1964), Romer (1966), Madsen and Miller (1979), Galton (1990), Galton and Upchurch (2004), Galton (2007) and Maidment et al. (2008); it was considered a nomen dubium by Carpenter and Galton (2001).

It was assigned to Camptonotidae by Marsh (1881); to Stegosauria by Marsh (1887), Marsh (1892) and Winkler (1893); to Omosauridae by Huene (1909); to Stegosaurinae by Nopcsa (1928); and to Stegosauridae by Sauvage (1882), Dollo (1884), Marsh (1884), Marsh (1885), Zittel (1890), Marsh (1895), Marsh (1896), Nopcsa (1901), Hay (1902), von Zittel (1911), Hay (1930), Olshevsky and Ford (1993) and Ulansky (2014).
Hypsirophus was named by Cope (1878). Its type is Hypsirhophus discurus.

It was synonymized subjectively with Stegosaurus by Sauvage (1882), Marsh (1884), Marsh (1885), Marsh (1896), Nopcsa (1901), Hay (1902), Hennig (1915), Romer (1956), Hoffstetter (1957), Tatarinov (1964), Kuhn (1964), Romer (1966), Galton (1990) and Maidment et al. (2008); it was misspelled as Hypsirhophus by Zittel (1890), Huene (1909) and von Zittel (1911); it was considered a nomen dubium by Galton and Upchurch (2004).

It was assigned to Stegosauria by Cope (1878); to Megalosauridae by Zittel (1890); to Saurischia by Huene (1909); to Theropoda by von Zittel (1911); and to Stegosauridae by Ulansky (2014).
Hypsirhophus seeleyanus was named by Cope (1879).

It was recombined as Stegosaurus seeleyanus by Nopcsa (1901), Hay (1902), Mook (1916), Hay (1930) and Kuhn (1964); it was synonymized subjectively with Stegosaurus armatus by Galton (1990) and Galton and Upchurch (2004); it was considered a nomen nudum by Maidment et al. (2008) and Galton (2010); it was recombined as Hypsirophus seeleyanus by Ulansky (2014).
Stegosaurus affinis was named by Marsh (1881). Its type specimen is YPM (lost?), a set of postcrania (o=pubis), and it is a 3D body fossil. Its type locality is Quarry 13, Como Bluff (YPM), which is in a Kimmeridgian/Tithonian crevasse splay sandstone/claystone in the Morrison Formation of Wyoming.

It was considered a nomen nudum by Gilmore (1914) and Hennig (1915); it was considered a nomen dubium by Galton (1990) and Galton and Upchurch (2004); it was considered a nomen nudum by Maidment et al. (2008) and Ulansky (2014).

Synonymy list

Year	Name and author
1877	Stegosaurus Marsh
1877	Stegosaurus armatus Marsh
1878	Hypsirophus Cope
1878	Stegosaurus armatus King p. 346
1878	Stegosaurus Williston p. 45
1879	Hypsirhophus seeleyanus Cope
1880	Stegosaurus Marsh p. 259
1881	Diracodon Marsh
1881	Stegosaurus Marsh
1881	Stegosaurus affinis Marsh p. 169
1881	Diracodon Marsh p. 421
1882	Stegosaurus Quenstedt p. 188
1882	Diracodon Sauvage p. 35
1882	Stegosaurus Sauvage p. 35
1884	Diracodon Dollo p. 298
1884	Stegosaurus Dollo p. 298
1884	Diracodon Marsh p. 68
1884	Stegosaurus Marsh p. 68
1885	Stegosaurus Dollo p. 39
1885	Diracodon Marsh p. 764
1885	Stegosaurus Marsh p. 764
1887	Diracodon Marsh p. 416
1887	Stegosaurus Marsh pp. 416-417
1889	Stegosaurus Dollo p. 678
1890	Hypsirhophus Zittel p. 726
1890	Stegosaurus Zittel p. 744
1890	Diracodon Zittel p. 748
1892	Diracodon Marsh
1892	Stegosaurus Marsh
1893	Stegosaurus Marsh p. 437
1893	Stegosaurus Winkler p. 105
1893	Stegosaurus armatus Winkler p. 105
1893	Diracodon Winkler p. 107
1895	Diracodon Marsh
1895	Stegosaurus Marsh
1896	Diracodon Marsh p. 242
1896	Stegosaurus Marsh p. 242
1897	Stegosaurus Gadow p. 205
1897	Stegosaurus armatus Marsh p. 526
1898	Stegosaurus Gadow p. 22
1901	Stegosaurus Gadow p. 425
1901	Diracodon Nopcsa p. 213
1901	Stegosaurus Nopcsa p. 215
1901	Stegosaurus affinis Nopcsa p. 215
1901	Stegosaurus seeleyanus Nopcsa p. 215
1902	Stegosaurus Hay p. 495
1902	Stegosaurus armatus Hay p. 495
1902	Diracodon Hay p. 496
1902	Stegosaurus affinis Hay p. 496
1902	Stegosaurus seeleyanus Hay p. 496
1902	Stegosaurus Mansel-Pleydell p. lxxx
1909	Hypsirhophus Huene p. 16
1909	Diracodon Huene p. 17
1909	Stegosaurus Huene p. 17
1911	Hypsirhophus von Zittel p. 283
1911	Stegosaurus von Zittel p. 293
1911	Diracodon von Zittel p. 294
1913	Stegosaurus Tornier p. 373
1914	Stegosaurus Gilmore p. 101
1914	Stegosaurus armatus Gilmore p. 104
1915	Stegosaurus Hennig p. 10
1915	Stegosaurus armatus Hennig p. 10
1915	Hypsirhophus seeleyanus Hennig p. 11
1916	Stegosaurus armatus Mook p. 143
1916	Stegosaurus affinis Mook p. 144
1916	Stegosaurus seeleyanus Mook p. 144
1918	Stegosaurus Lambe p. 32
1922	Stegosaurus Joleaud p. 63
1924	Stegosaurus Lull p. 242
1926	Stegosaurus Piveteau p. 36
1928	Diracodon Nopcsa p. 185
1928	Stegosaurus Nopcsa p. 185
1930	Stegosaurus Hay p. 233
1930	Stegosaurus affinis Hay p. 234
1930	Stegosaurus armatus Hay p. 234
1930	Stegosaurus seeleyanus Hay p. 234
1930	Diracodon Hay p. 235
1931	Stegosaurus armatus Johnson p. 358
1934	Stegosaurus Chakravarti p. 78
1956	Stegosaurus Romer p. 634
1958	Stegosaurus Hoffstetter and Brun p. 71
1959	Stegosaurus Young pp. 7-8
1960	Stegosaurus Delair p. 88
1964	Stegosaurus Kuhn p. 37
1964	Stegosaurus armatus Kuhn p. 37
1964	Stegosaurus affinis Kuhn p. 38
1964	Stegosaurus seeleyanus Kuhn p. 38
1964	Stegosaurus Tatarinov p. 572
1966	Stegosaurus Romer p. 370
1967	Stegosaurus Charig p. 715
1970	Stegosaurus Swinton p. 236
1973	Wuerhosaurus Dong p. 50
1977	Stegosaurus Galton p. 230
1979	Stegosaurus Madsen and Miller p. 5
1980	Stegosaurus Galton p. 832
1981	Wuerhosaurus Galton p. 43
1981	Stegosaurus McIntosh p. 35
1983	Stegosaurus Dong et al. p. 137
1983	Wuerhosaurus Dong et al. p. 137
1983	Wuerhosaurus Zhao p. 304
1983	Stegosaurus Zhou p. 26
1984	Stegosaurus Russell p. 23
1986	Stegosaurus Bonaparte p. 84
1986	Stegosaurus Sereno
1986	Wuerhosaurus Sereno
1986	Stegosaurus Zhou p. 36
1986	Wuerhosaurus Zhou p. 36
1988	Stegosaurus Carroll
1988	Wuerhosaurus Carroll
1990	Stegosaurus armatus Bakker p. 2
1990	Wuerhosaurus Dong p. 262
1990	Stegosaurus Galton
1990	Wuerhosaurus Galton
1991	Stegosaurus Miller et al. p. 40
1992	Wuerhosaurus Dong p. 166
1993	Diracodon Olshevsky and Ford
1993	Stegosaurus Olshevsky and Ford
1993	Stegosaurus armatus Olshevsky and Ford
1993	Wuerhosaurus Olshevsky and Ford
1994	Wuerhosaurus Dong p. 2174
1997	Stegosaurus Dodson p. 12
1998	Stegosaurus Sereno p. 61
1999	Stegosaurus armatus Carpenter p. 9
2001	Stegosaurus Blows p. 138
2001	Wuerhosaurus Blows p. 138
2001	Stegosaurus armatus Carpenter and Galton p. 81
2001	Wuerhosaurus Carpenter et al. p. 73 fig. 3.14
2004	Stegosaurus Galton and Upchurch p. 345
2004	Stegosaurus armatus Galton and Upchurch p. 345
2004	Wuerhosaurus Galton and Upchurch p. 345
2006	Stegosaurus Chure et al. p. 237
2006	Stegosaurus armatus Chure et al. p. 237
2006	Stegosaurus Maidment et al. p. 951 fig. 8
2006	Stegosaurus armatus Mateus p. 231
2007	Stegosaurus Escaso et al. p. 158
2007	Stegosaurus armatus Escaso et al. p. 371
2007	Stegosaurus Galton p. 24
2007	Stegosaurus armatus Galton p. 24
2008	Stegosaurus armatus Maidment et al. pp. 377-378
2008	Stegosaurus Maidment et al. p. 390 fig. 11
2009	Stegosaurus Mateus et al.
2009	Stegosaurus armatus Mateus et al.
2010	Stegosaurus armatus Billon-Bruyat et al. p. 147
2010	Stegosaurus armatus Christiansen and Tschopp p. 165
2010	Stegosaurus Mateus and Milàn p. 254
2010	Stegosaurus armatus Yates p. 746
2011	Stegosaurus armatus Barrett and Maidment p. 404
2013	Stegosaurus armatus Ruiz-Omeñaca et al. p. 37
2014	Diracodon Ulansky p. 5
2014	Hypsirophus Ulansky p. 5
2014	Hypsirophus seeleyanus Ulansky p. 5
2014	Stegosaurus Ulansky p. 7
2014	Stegosaurus armatus Ulansky p. 7
2014	Wuerhosaurus Ulansky p. 8
2014	Stegosaurus armatus Ulansky p. 20
2018	Wuerhosaurus Tumanova and Alifanov p. 1771

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Rank	Name	Author
kingdom	Animalia	()
—	Bilateria
—	Eubilateria	Ax 1987
—	Deuterostomia
phylum	Chordata	Haeckel 1874
subphylum	Vertebrata
superclass	Gnathostomata
—	Osteichthyes	()
subclass	Sarcopterygii	()
subclass	Dipnotetrapodomorpha	(Nelson 2006)
subclass	Tetrapodomorpha	()
—	Tetrapoda
—	Reptiliomorpha
—	Anthracosauria
subclass	Amphibiosauria	Kuhn 1967
—	Cotylosauria	()
—	Amniota
—	Sauropsida
class	Reptilia

Rank	Name	Author
subclass	Eureptilia	()
—	Romeriida
—	Diapsida	()
—	Archosauromorpha	(Huene 1946)
—	Crocopoda
—	Archosauriformes	Gauthier 1986
—	Eucrocopoda
—	Archosauria	()
informal	Avemetatarsalia
—	Ornithodira
—	Dinosauromorpha
—	Dinosauriformes
—	Dinosauria	()
—	Ornithischia	()
—	Genasauria
—	Thyreophora	()
—	Stegosauria	()
family	Stegosauridae
genus	Stegosaurus

If no rank is listed, the taxon is considered an unranked clade in modern classifications. Ranks may be repeated or presented in the wrong order because authors working on different parts of the classification may disagree about how to rank taxa.

G. †Stegosaurus Marsh 1877

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†Stegosaurus armatus Marsh 1877

†Stegosaurus duplex Marsh 1887

†Stegosaurus stenops Marsh 1887

†Stegosaurus sulcatus Marsh 1887

†Stegosaurus ungulatus Marsh 1879

Invalid names: Diracodon Marsh 1881 [synonym], Hypsirophus Cope 1878 [synonym], Stegosaurus affinis Marsh 1881 [nomen nudum], Stegosaurus armatus Marsh 1877 [nomen dubium], Wuerhosaurus Dong 1973 [synonym]

Diagnosis

Reference	Diagnosis
C. W. Gilmore 1914	Skull relatively very small and brain cavity in proportion to size of the body more diminutive than in any other land vertebrate. Supraorbital region composed of two separate bones. Eamus deep and without lateral foramen. Dentition 23+/23. Teeth extremely small and weak. Vertebrae slightly amphicoelus, or with flat ends; dorsals with much elevated neural arches. Neural canal in sacrum enlarged to many times the capacity of the brain. Sacrum and lateral processes entirely roofed over by bone. Anterior caudal vertebra largest in the column. Ulna (in adults) as long as humerus, with large olecranon process. Manus short, pentadactyle. Phalangial formula of digits III and IV apparently reduced. Femur long, straight, fourth trochanter vestigal, with or without lesser trochanter. Tibia having greatest diameter of two ends in the same plane. Pes tetradactyle, digit IV consisting of a vestigal metatarsal, digit V wanting. Dermal armor consisting of two rows of erect, flattened plates extending from back of head to distal fourth of tail. Plates of opposite rows alternating. Four dermal spines near end of tail.
Z.-M. Dong 1994 (Wuerhosaurus)	Differs from all other stegosaurs in having only 11 dorsal vertebrae, compared with 16 in Stegosaurus and 17-18 in Huayangosaurus. Neural canal of dorsals small, not enlarged as in Stegosaurus.
S. C. R. Maidment et al. 2008	Stegosaurus possesses the following autapomorphies: quadrate–squamosal–paroccipital process articulation overhangs the retroarticular process of the lower jaw; postzygapophyses on posterior cervical vertebrae are elongated posteriorly and overhang the back of the centrum; trans-verse processes on anterior caudal vertebrae (except for caudals one and two) project ventrally rather than laterally; large,rectangular acromial process of the scapula; supra-acetabular process diverges at an angle of 90◦from the anterior process of the ilium; medial process present on the posterior iliac process of the ilium. Additional synapomorphies using DELTRAN: • Quadrate head strongly arched posteriorly in lateral view (equivocal in other Stegosauridae) • Dorsal shield of sacrum not perforated by foramina in between ribs (convergent in Kentrosaurus)

Measurements

No measurements are available

Composition:

hydroxyapatiteo

Entire body:

yesg

Adult length:

10 to < 100o

Adult width:

1.0 to < 10o

Adult height:

1.0 to < 10o

Maximum body mass:

10000 kgg

Minimum body mass:

1000 kgg

Architecture:

compact or denseo

Ontogeny:

accretion, modification of partso

Grouping:

gregariouso

Environment:

terrestrialo

Locomotion:

actively mobileo

Life habit:

ground dwellingo

Diet:

herbivoreo

Reproduction:

oviparouso

Dispersal:

direct/internalo

Dispersal 2:

mobileo

Created:

2005-08-25 06:07:59

Modified:

2005-08-25 08:07:59

Source: g = genus, o = order

References: Marsh 1875, Peczkis 1995

Age range: base of the Late/Upper Kimmeridgian to the top of the Early/Lower Cenomanian or 155.70000 to 93.50000 Ma

Collections (78 total)

Time interval	Ma	Country or state	Original ID and collection number
Late/Upper Jurassic	161.5 - 145.0	USA (Wyoming)	S. sp. (62561)
Kimmeridgian	157.3 - 152.1	USA (Wyoming)	S. sp. (46468 58510 75453 176983)
Kimmeridgian	157.3 - 152.1	USA (Montana)	S. sp. (69890)
Kimmeridgian	157.3 - 152.1	USA (Colorado)	S. sp. (154924) S. stenops (48170)
Kimmeridgian	157.3 - 152.1	USA (Utah)	S. sp. (58515)
Kimmeridgian	157.3 - 152.1	Portugal (Centro)	S. ungulatus (73610)
Kimmeridgian - Tithonian	157.3 - 145.0	USA (Utah)	S. sp. (49626 58514 58516 220417)
Kimmeridgian - Tithonian	157.3 - 145.0	USA (New Mexico)	S. sp. (188393 225132)
Kimmeridgian - Tithonian	157.3 - 145.0	USA (Wyoming)	Stegosauridae indet. (227262) S. sp. (13214 13352 22648 39340 39342 39372 48837 49627 49628 52815 52816 55323 55483 57894 57896 57897 57899 57900 230774 231553 231575 231578) S. sp., S. ungulatus, Diracodon laticeps, S. stenops, S. sulcatus, S. affinis (39253) S. ungulatus (39369 39370)
Kimmeridgian - Tithonian	157.3 - 145.0	USA (Colorado)	S. sp. (25141 48164 56586 56684 184626 192450 231533)
Late/Upper Kimmeridgian	155.7 - 150.8	Portugal (Centro)	S. sp. (91397)
Late/Upper Kimmeridgian - Early/Lower Tithonian	155.7 - 145.0	USA (Colorado)	S. armatus (28382) S. armatus, S. stenops (28366) S. sp. (45975 48160)
Late/Upper Kimmeridgian - Early/Lower Tithonian	155.7 - 145.0	USA (Wyoming)	S. stenops (49577)
Late/Upper Kimmeridgian - Tithonian	155.7 - 145.0	USA (Colorado)	S. sp. (38883 70032) S. sp., S. stenops (231620)
Late/Upper Kimmeridgian - Tithonian	155.7 - 145.0	USA (Wyoming)	S. sp. (22678)
Late/Upper Kimmeridgian - Tithonian	155.7 - 145.0	USA (Oklahoma)	S. sp. (49338 49596 49597 56421)
Tithonian	152.1 - 145.0	USA (Wyoming)	S. sp. (39347)
Tithonian	152.1 - 145.0	USA (Colorado)	Hypsirophus discurus (48129) S. sp. (55329 154925 231619) S. stenops (48161)
Tithonian	152.1 - 145.0	USA (Utah)	S. sp. (22711 57913) S. sp., S. sp. (46439)
Early/Lower Tithonian	150.8 - 145.0	USA (Colorado)	S. sp. (71476)
Early/Lower Tithonian	150.8 - 145.0	USA (Utah)	S. sp., S. ungulatus (21852)
Valanginian - Albian	139.8 - 100.5	China (Nei Mongol)	Wuerhosaurus homheni (46905)
Valanginian - Albian	139.8 - 100.5	China (Xinjiang)	Wuerhosaurus homheni (49047 49817)
Early/Lower Cenomanian	99.6 - 93.5	USA (Utah)	S. sp. (31193)