Open Paleo

Shamosaurus

Tumanova, 1983 SHAH-maw-SAWR-us

From Mandarin Chinese 'sha mo' (sand desert, the Chinese name for the Gobi Desert) + Greek 'sauros' (lizard), meaning 'Gobi desert lizard'.

121.4–100.5 million years ago Aptian–Albian, Early Cretaceous
Early Cretaceous stages

Shamosaurus is an extinct genus of herbivorous basal ankylosaurid ankylosaur from Early Cretaceous (Aptian to Albian stage) deposits of Höövör, Mongolia.

Diagnosis

  1. Skull roof entirely covered by osteoderms with a fine tuberculate sculpture
  2. Postorbital osteoderms form low pyramids rather than spines
  3. Osteodermal covering does not conceal the quadrate condyle in lateral view
  4. Orbits face almost directly sideways and lie at the midpoint of the skull length
  5. Front of the snout narrowly oval, much narrower than the distance between the posterior maxillary teeth
  6. Tooth row longer than in any other known large ankylosaur

Species

Shamosaurus scutatus Tumanova, 1983

Type species

From Latin 'scutatus' meaning 'protected by a shield', a reference to the extensive body armor of the animal.

Holotype
PIN N 3779/2 , Paleontological Institute, Russian Academy of Sciences
Material
Skull, partial postcranial skeleton and armor
Horizon
Zuunbayan Formation, Aptian–Albian, Early Cretaceous , 121.4–100.5 million years ago
Locality
Khamryn-Us, Dornogovi, Mongolia

References

  1. Tumanova, T. A. (1983). Pervyy ankilozavr iz nizhnego mela Mongolii [The first ankylosaur from the Lower Cretaceous of Mongolia]. Iskopayemyye reptilii Mongolii [Fossil Reptiles of Mongolia] (Tatarinov, L. P.; Barsbold, R.; Vorobyeva, E.; Luvsandanzan, B.; Trofimov, B. A.; Reshetov, Yu. A.; Shishkin, M. A., eds.) 24: 110-118. tumanova1983a
  2. Tumanova, T. A. (1987). Pantsirnyye dinozavry Mongolii [The armored dinosaurs of Mongolia]. Trudy Sovmestnaya Sovetsko-Mongol'skaya Paleontologicheskaya Ekspeditsiya 32: 1-80.

    Source of the holotype material, which lists the partial postcranial skeleton and armor under the same number as the skull.

    tumanova1987a
  3. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Ornithischians. Princeton University Press.

    Source of the hip height estimate, and the appearance features.

    jones2026a
  4. Arbour, V. M.; Currie, P. J. (2015). Systematics, phylogeny and palaeobiogeography of the ankylosaurid dinosaurs. Journal of Systematic Palaeontology 14(5): 385-444. Informa UK Limited. doi:10.1080/14772019.2015.1059985

    Gives the holotype locality as Khamryn-Us and treats Dzunbain as an older transliteration of the Zuunbayan Formation.

    arbour2015a