Hanson Formation


The Hanson Formation is a geologic formation on Mount Kirkpatrick, Antarctica. It is one of only two major dinosaur-bearing rock groups found on the continent of Antarctica to date; the other is the Snow Hill Island Formation and related formations from the Late Cretaceous of the Antarctic Peninsula. The formation has yielded only a handful of Mesozoic specimens so far and most of it is as yet unexcavated. Part of the Victoria Group of the Transantarctic Mountains, it is below the Prebble Formation and above the Falla Formation. The Formation is related to the Volcanic Activity Linked to the Karoo-Ferar eruptions on the Lower Jurassic. The climate of the zone was similar to the modern Southern Chile, Humid, with a temperature interval of 17-18 degrees.

Paleofauna

The first dinosaur to be discovered from the Hanson Formation was the predator Cryolophosaurus in 1991, which was then formally described in 1994. Alongside these dinosaur remains were fossilized trees, suggesting that plant matter had once grown on Antarctica's surface before it drifted southward. Other finds from the formation include tritylodonts, herbivorous mammal-like reptiles and crow-sized pterosaurs. Surprisingly were the discovery of prosauropod remains, which were found commonly on other continents only until the Early Jurassic. However, the bone fragments found at the Hanson Formation were dated until the Middle Jurassic, millions of years later. In 2004, paleontologists discovered partial remains of a large sauropod dinosaur that has not formally been described yet.

Invertebrate paleofauna

The insects Ademosynoides & Grahamelytron were claimed to be found on this formation, but they come from the Bajocian of a different formation. Coleoptera and Blattoidea wings have been found.

Bony fish

Synapsids

Pterosaurs

Dinosaurs

Flora

Fossilized wood is also present in the Hanson Formation, near the stratigraphic level of the tritylodont locality. It has affinities with the Araucariaceae and similar kinds of conifers.

Macroflora