Glacialisaurus

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. The fossils were described in 2007, and made the basis of the new genus and species Glacialisaurus hammeri. The genus name translates as “icy” or "frozen lizard”, and the specific name honors Hammer.

This dinosaur has been classified as a massospondylid, a group of medium-sized, basal (early diverging or "primitive") sauropodomorphs that existed during the Late Triassic and Early Jurassic on every continent except Australia. Its length has been estimated at . Glacialisaurus was a large herbivorous dinosaur, though it was average sized for a massospondylid. Glacialisaurus was distinct from other sauropodomorphs in features such as having a robust medial epicondylar ridge on the lower femur, a robust adductor ridge extending from the upper end of the femoral medial condyle, and a second metatarsal with a front border that is weakly convex in the upper end.