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Glacialisaurus

Smith & Pol, 2007 glay-see-al-eye-sor-us

From Latin glacialis, 'icy' or 'frozen', + Greek sauros, 'lizard'; means 'icy lizard' or 'frozen lizard', referring to its discovery in Antarctica

199.5–184.2 million years ago Sinemurian–Pliensbachian, Early Jurassic
Early Jurassic stages

Glacialisaurus is a genus of sauropodomorph dinosaur from the Early Jurassic period of Antarctica. It is known from two specimens; the holotype (name-bearing specimen), a partial tarsus (ankle) and metatarsus, and a partial left femur (thigh bone). The fossils were collected by a team led by paleontologist William R. Hammer during a 1990-91 field expedition to the central region of the Transantarctic Mountains. They come from sedimentary rocks of the Hanson Formation and date to the Pliensbachian stage of the Early Jurassic, around 186 to 182 million years ago.

Diagnosis

  1. Robust medial epicondylar ridge on the distal femur
  2. Robust adductor ridge extending from the proximal end of the femoral medial condyle
  3. Second metatarsal with an anterior border that is weakly convex in proximal aspect
  4. Hypertrophied lateral plantar flange on the proximal end of metatarsal II
  5. Second metatarsal gently twisted medially about its long axis at the distal end of its shaft
  6. Second metatarsal with a medial distal condyle that is more robust and well-developed than the lateral distal condyle

Species

Glacialisaurus hammeri Smith & Pol, 2007

Type species

Named for William R. Hammer, the paleontologist who led the 1990-91 Antarctic field expedition that recovered the holotype, in recognition of contributions to Antarctic paleontology.

Holotype
FMNH PR 1823 , Field Museum of Natural History
Material
Partial right astragalus, medial and lateral distal tarsals, and partial right metatarsus preserved in articulation with each other.
Horizon
lower Hanson Formation, Sinemurian–Pliensbachian, Early Jurassic , 199.5–184.2 million years ago
Locality
Mt. Kirkpatrick, Beardmore Glacier region, Central Transantarctic Mountains, Antarctica

References

  1. Smith, N. D.; Pol, D. (2007). Anatomy of a basal sauropodomorph dinosaur from the Early Jurassic Hanson Formation of Antarctica. Acta Palaeontologica Polonica 52(4): 657-674. doi:10.5281/zenodo.13741285 smith2007a
  2. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Sauropods. Princeton University Press.

    Source of the mass and hip height estimates.

    jones2026b