The Rolling Downs Group is a stratigraphic group present in the Eromanga and

Surat Surat (Gujarati Language, Gujarati: ) is a city in the western Indian States and territories of India, state of Gujarat. The word Surat directly translates to ''face'' in Urdu, Gujarati language, Gujarati and Hindi. Located on the banks of t ...

Basins Basin may refer to: Geography and geology * Depression (geology) ** Back-arc basin, a submarine feature associated with island arcs and subduction zones ** Debris basin, designed to prevent damage from debris flow ** Drainage basin (hydrology), ...

in eastern

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

, which was deposited between the mid

Barremian The Barremian is an age in the geologic timescale (or a chronostratigraphic stage) between 125.77 Ma (million years ago) and 121.4 ± 1.0 Ma (Historically, this stage was placed at 129.4 million to approximately 125 million years ago) It is a ...

to early

Turonian The Turonian is, in the International Commission on Stratigraphy, ICS' geologic timescale, the second age (geology), age in the Late Cretaceous epoch (geology), Epoch, or a stage (stratigraphy), stage in the Upper Cretaceous series (stratigraphy), ...

of the

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...

period. It primarily consists of nearshore shallow marine sediments deposited in the

Eromanga Sea The Eromanga Sea was an inland sea across the Australian continent that formed in the Early Cretaceous. The sea extended from the Eromanga Basin northward to the Carpentarian Basin. Its southern extents comprised lagoons and rivers, and to the ea ...

, though the uppermost and terminal members, the

Winton Formation The Winton Formation is a Cretaceous Formation (geology), geological formation in central-western Queensland, Australia. It is late Albian to early Turonian in age. The formation blankets large areas of central-western Queensland. It consists of ...

and the

Griman Creek Formation The Griman Creek Formation is a geological formation in northern New South Wales and southern Queensland, Australia whose strata date back to the Albian-Cenomanian stages of the mid-Cretaceous. It is most notable being a major source of opal, ...

represents freshwater deposits. It is notable for its fossil content including many

dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic Geological period, period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the #Evolutio ...

s and

mammal A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three ...

s, as well as opal. A relict species of

dicynodont Dicynodontia is an extinct clade of anomodonts, an extinct type of non-mammalian therapsid. Dicynodonts were herbivores that typically bore a pair of tusks, hence their name, which means 'two dog tooth'. Members of the group possessed a horny, t ...

was suggested to have been found in these rocks, but is more likely to be misidentified pieces of a

Cenozoic The Cenozoic Era ( ; ) is Earth's current geological era, representing the last 66million years of Earth's history. It is characterized by the dominance of mammals, insects, birds and angiosperms (flowering plants). It is the latest of three g ...

marsupial Marsupials are a diverse group of mammals belonging to the infraclass Marsupialia. They are natively found in Australasia, Wallacea, and the Americas. One of marsupials' unique features is their reproductive strategy: the young are born in a r ...

from younger sediments.

References

{{Reflist Geologic groups of Oceania Geologic formations of Australia Cretaceous System of Australia Early Cretaceous Australia Albian Stage Aptian Stage Barremian Stage Cenomanian Stage Turonian Stage Fossiliferous stratigraphic units of Oceania Paleontology in Australia Geology of New South Wales Geology of Queensland Geology of South Australia