Open Paleo

Stegosauria

Marsh, 1877 Type genus Stegosaurus

Its genera lived 170.9–100.5 million years ago Middle Jurassic–Early Cretaceous

Stegosauria is a clade of herbivorous, armored ornithischian dinosaurs belonging to the Thyreophora, best known for the arrays of bony plates and spikes that run along the back, hips, and tail. Stegosaurs lived from the Middle Jurassic into the Early Cretaceous, with fossils recovered mostly across the Northern Hemisphere as well as Africa and South America. They were quadrupedal plant-eaters with small, narrow heads and hindlimbs much longer than the forelimbs, and a broad pelvis that held the tail out almost horizontally behind the animal. The tail ended in paired spikes, informally called a thagomizer, which at least in older adults served as a defensive weapon. The clade contains two families: the small, early-diverging Huayangosauridae and the larger, more diverse Stegosauridae, which account for the great majority of known genera and reached their peak diversity in the Late Jurassic before declining through the Cretaceous.

Diagnosis

  1. Parasagittal rows of alternating or paired dorsal plates and/or spines
  2. Tail spines (thagomizer) used for defense
  3. Hindlimbs substantially longer than forelimbs
  4. Small skull with simple, leaf-shaped teeth and weak jaw musculature
  5. Low, arched body profile
  6. Relatively small brain (low encephalization quotient)

Clades within Stegosauria

Genera placed directly in Stegosauria

  • Amargastegos Nomen dubium Ulansky, 2014 Barremian (125.8–121.4 Ma)Argentinaincertae sedis
  • Baiyinosaurus Li et al., 2024 Bathonian (168.2–165.3 Ma)China
  • Bashanosaurus Dai et al., 2022 Bajocian (170.9–168.2 Ma)China
  • Chialingosaurus Nomen dubium Young, 1959 Bajocian–Oxfordian (170.9–154.8 Ma)Chinaincertae sedis
  • Chungkingosaurus Dong et al., 1983 Bajocian–Oxfordian (170.9–154.8 Ma)Chinaincertae sedisunder dispute
  • Craterosaurus Nomen dubium Seeley, 1874 Berriasian–Aptian (143.1–113.2 Ma)United Kingdomincertae sedis
  • Gigantspinosaurus Ouyang, 1992 Bajocian–Oxfordian (170.9–154.8 Ma)China
  • Huayangosaurus Dong et al., 1982 Bajocian–Oxfordian (170.9–154.8 Ma)Chinaincertae sedisunder dispute
  • Hypsirhophus Disputed Cope, 1878 Oxfordian–Berriasian (161.5–137.1 Ma)United Statesincertae sedis
  • Isaberrysaura Salgado et al., 2017 Bajocian (170.9–168.2 Ma)Argentinaincertae sedis
  • Mongolostegus Tumanova & Alifanov, 2018 Aptian–Albian (121.4–100.5 Ma)Mongoliaincertae sedisunder dispute
  • Monkonosaurus Nomen dubium Dong, 1990 Kimmeridgian–Hauterivian (154.8–125.8 Ma)Chinaincertae sedis
  • Yingshanosaurus Zhu, 1994 Bajocian–Oxfordian (170.9–154.8 Ma)China

References

  1. Marsh, O. C. (1877). A new order of extinct Reptilia (Stegosauria) from the Jurassic of the Rocky Mountains. American Journal of Science s3-14(84): 513-514. doi:10.2475/ajs.s3-14.84.513

    Erected the order Stegosauria.

    marsh1877a
  2. Maidment, S. C. R.; Norman, D. B.; Barrett, P. M.; Upchurch, P. (2008). Systematics and phylogeny of Stegosauria (Dinosauria: Ornithischia). Journal of Systematic Palaeontology 6(4): 367-407. Informa UK Limited. doi:10.1017/S1477201908002459

    Comprehensive systematic revision of Stegosauria.

    maidment2008a