The South Polar region of the Cretaceous comprised the continent of East Gondwana–modern day Australia, Zealandia, and Antarctica–a product of the break-up of Gondwana in the Cretaceous Period. The southern region, during this time, was much warmer than it is today, ranging from perhaps 4–8 °C (39–46 °F) in the latest Cretaceous Maastrichtian in what is now southeastern Australia. This prevented permanent ice sheets from developing and fostered polar forests, which were largely dominated by conifers, cycads, and ferns, and relied on a temperate climate and heavy rainfall. Major fossil-bearing geological formations that record this area are: the Santa Marta and Sobral Formations of Seymour Island off the Antarctic Peninsula; the Snow Hill Island, Lopez de Bertodano, and the Hidden Lake Formations on James Ross Island also off the Antarctic Peninsula; and the Eumeralla and Wonthaggi Formations in Australia.
Kronosaurus is an extinct genus of large short-necked pliosaur that lived during the Aptian to Albian stages of the Early Cretaceous in what is now Australia. The first known specimen was received in 1899 and consists of a partially preserved mandibular symphysis, which was first thought to come from an ichthyosaur according to Charles De Vis. However, it was 1924 that Albert Heber Longman formally described this specimen as the holotype of an imposing pliosaurid, to which he gave the scientific name K. queenslandicus, which is still the only recognized species nowadays. The genus name, meaning "lizard of Kronos", refers to its large size and possible ferocity reminiscent of the Titan of the Greek mythology, while the species name alludes to Queensland, the Australian state of its discovery. In the early 1930s, the Harvard Museum of Comparative Zoology sent an organized expedition to Australia that recovered two specimens historically attributed to the taxon, including a well known partial skeleton that is now massively restored in plaster. Several attributed fossils were subsequently discovered, including two large, more or less complete skeletons proposed as potential neotypes. Two additional species were proposed, but these are now seen as invalid or belonging to another genus.
The Aptian is an age in the geologic timescale or a stage in the stratigraphic column. It is a subdivision of the Early or Lower Cretaceous Epoch or Series and encompasses the time from 121.4 ± 1.0 Ma to 113.0 ± 1.0 Ma, approximately. The Aptian succeeds the Barremian and precedes the Albian, all part of the Lower/Early Cretaceous.
The Surat Basin is a geological basin in eastern Australia. It is part of the Great Artesian Basin drainage basin of Australia. The Surat Basin extends across an area of 270,000 square kilometres and the southern third of the basin occupies a large part of northern New South Wales, the remainder is in Queensland. It comprises Jurassic through to Cretaceous aged sediments derived from Triassic and Permian arc rocks of the Hunter-Bowen orogeny. Towns situated above the basin, once dominated by agriculture, are experiencing a boom as mines and infrastructure in the area are expanded.
Umoonasaurus is an extinct genus of plesiosaur belonging to the family Leptocleididae. This genus lived approximately 115 million years ago during the Early Cretaceous period, in shallow seas covering parts of what is now Australia. It was a relatively small animal around 2.5 metres (8.2 ft) long. An identifying trait of Umoonasaurus is three crest-ridges on its skull.
The Wealden Group, occasionally also referred to as the Wealden Supergroup, is a group in the lithostratigraphy of southern England. The Wealden group consists of paralic to continental (freshwater) facies sedimentary rocks of Berriasian to Aptian age and thus forms part of the English Lower Cretaceous. It is composed of alternating sands and clays. The sandy units were deposited in a flood plain of braided rivers, the clays mostly in a lagoonal coastal plain.
Woolungasaurus is a dubious genus of plesiosaur, an extinct marine reptile, belonging to the Elasmosauridae.
Notopala is a genus of moderately large to large, freshwater snails with an operculum, aquatic gastropod mollusks in the family Viviparidae, the river snails or mystery snails.
Leptocleidus is an extinct genus of plesiosaur, belonging to the family Leptocleididae. It was a small plesiosaur, measuring only up to 3 m (9.8 ft).
The Eromanga Basin is a large Mesozoic sedimentary basin in central and northern Australia. It covers parts of Queensland, the Northern Territory, South Australia, and New South Wales, and is a major component of the Great Artesian Basin. The Eromanga Basin covers 1,000,000 km2 and overlaps part of the Cooper Basin.
The Toolebuc Formation is a geological formation that extends from Queensland across South Australia and the Northern Territory in Australia, whose strata date back to the Albian stage of the Early Cretaceous. Dinosaurs, pterosaurs, plesiosaurs, ichthyosaurs, protostegid turtles, sharks, chimaeroids and bony fish remains are among the fossils that have been recovered from the formation.
The Marree Subgroup, previously described as Maree Formation and Marree Formation, is a geological subgroup in the Eromanga Basin of South Australia whose strata date back to the Aptian. The subgroup was first described as a formation by Forbes in 1966. Dinosaur remains are among the fossils that have been recovered from the formation.
Geologically the Australian state of New South Wales consists of seven main regions: Lachlan Fold Belt, the Hunter-Bowen Orogeny or New England Orogen (NEO), the Delamerian Orogeny, the Clarence Moreton Basin, the Great Artesian Basin, the Sydney Basin, and the Murray Basin.
Hastanectes is an extinct genus of a plesiosaurian with possible pliosaurid affinities known from the Early Cretaceous Wadhurst Clay Formation of the United Kingdom. It contains a single species, Hastanectes valdensis, which was originally thought to be a species of Cimoliasaurus.
Vectocleidus is an extinct genus of leptocleidid plesiosaurian known from the Early Cretaceous Vectis Formation of Isle of Wight, in the United Kingdom. It contains a single species, Vectocleidus pastorum.
The Isachsen Formation is a geologic formation in Nunavut. It preserves fossils of Polycotylidae indet., dating back to the Aptian stage of the Cretaceous period.
Leyvachelys is an extinct genus of turtles in the family Sandownidae from the Early Cretaceous of the present-day Altiplano Cundiboyacense, Eastern Ranges, Colombian Andes. The genus is known only from its type species, Leyvachelys cipadi, described in 2015 by Colombian paleontologist Edwin Cadena. Fossils of Leyvachelys have been found in the fossiliferous Paja Formation, close to Villa de Leyva, Boyacá, after which the genus is named. The holotype specimen is the oldest and most complete sandownid turtle found to date.
The Uitenhage Group is one of three geological groups, which comprise the onshore and offshore post-Karoo middle to lower Upper Mesozoic geological rock units in South Africa. Stratigraphically, the Uitenhage Group overlies the Suurberg Group and is overlain by the Algoa Group. It contains four formations that range in age from late Early Jurassic and late Early Cretaceous in age.
The Bulldog Shale is a formation of Early Cretaceous age that forms part of the Marree Subgroup of the Rolling Downs Group, located in the Eromanga Basin of South Australia, Queensland and New South Wales.
Eiectus is a potentially valid genus of extinct short-necked pliosaur that lived in the Early Cretaceous period. Fossil material has been recovered from the Wallumbilla Formation (Aptian) of Queensland was initially classified under the related genus Kronosaurus until 2021.
New South Wales 
Northern Territory 
Queensland 
South Australia 
Australia 
