Glacialisaurus is a genus of massospondylidsauropodomorphdinosaur. It lived during the Early Jurassicperiod in what is now central Transantarctic Mountains of Antarctica. It is known from the holotypeFMNH PR1823, a partial hind limb (foot) and from the referred material FMNH PR1822, a left femur. The size of the largest specimen (FMNHPR1822) has been estimated at 6.25 m (20.5 ft) and 590 kg (1,300 lb).[2]
It was discovered and collected in the tuffaceous siltstones and mudstones of the lower part of the Hanson Formation, in Mount Kirkpatrick. It was first named by and in 2007 and the type species is Glacialisaurus hammeri.[3] The generic name, Glacialisaurus, is derived from the Latin word glacialis, meaning "icy" or "frozen", in reference to the Beardmore Glacier region in the Central Transantarctic Mountains, where the fossil remains were found. The specific name, G. hammeri, honors Dr. William R. Hammer of Augustana College, who made major contributions to both paleontology and Antarctic research.[3][4]
Phylogeny[]
Model of G. hammeri, Field Museum of Natural History (smaller specimen is of a not-yet-named prosauropod also from Antarctica.)
Femur fragment
In their phylogenetic analysis of the relationships of Glacialisaurus, Smith and Pol found that it is a massospondylid, a non-eusauropod sauropodomorph more advanced than other forms such as Saturnalia and Plateosaurus. Features of its foot are similar to Lufengosaurus (from the Early Jurassic of China), and the phylogenetic study suggests that Lufengosaurus may have been a close relative of Glacialisaurus, whereas other massospondylids such as Coloradisaurus and Massospondylus found to be more basal forms.[3] Recent cladistic analyses by Yates (2007), Yates et al. (2010, 2011) and Novas et al. (2011) found the same results.[5][6] The discovery of Glacialisaurus is important to the study of the early distribution of sauropod dinosaurs. The presence of this primitive sauropodomorph in the Hanson Formation (which has also yielded remains attributed to true sauropods) shows that both primitive and advanced members of this lineage existed side by side in the early Jurassic Period.[3][7]
^Molina-Perez & Larramendi (2020). Dinosaur Facts and Figures: The Sauropods and Other Sauropodomorphs. New Jersey: Princeton University Press. p. 247.
^"A big find". Scientists describe previously undiscovered dinosaur that lived 190 million years ago. The Antarctic Sun. December 20, 2007. Retrieved 2008-01-13.
^Yates, Adam M. (2007). "The first complete skull of the Triassic dinosaur Melanorosaurus Haughton (Sauropodomorpha: Anchisauria)". In Barrett, Paul M.; Batten, David J. (eds.). Special Papers in Palaeontology. Vol. 77. London: The Palaeontological Assoc. pp. 9–55. ISBN978-1-4051-6933-2.
^Fernando E. Novas; Martin D. Ezcurra; Sankar Chatterjee; T. S. Kutty (2011). "New dinosaur species from the Upper Triassic Upper Maleri and Lower Dharmaram formations of central India". Earth and Environmental Science Transactions of the Royal Society of Edinburgh. 101 (3–4): 333–349. doi:10.1017/S1755691011020093. S2CID128620874.
