Rolling Downs Group

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Rolling Downs Group
Stratigraphic range: Mid Barremian-Early Turonian
~127–90  Ma
Type Group
Sub-units
  • Wilgunya Subgroup
Underlies Quaternary Lake Eyre Basin sediments
Overlies Cadna-Owie Formation, Bungil Formation
Thicknessup to 1,200 m (3,900 ft)
Lithology
Primary Mudstone, siltstone, sandstone
Other Limestone, claystone
Location
Coordinates 22°36′S143°00′E / 22.6°S 143.0°E / -22.6; 143.0
RegionFlag of New South Wales.svg  New South Wales
Flag of Queensland.svg  Queensland
Flag of South Australia.svg  South Australia
CountryFlag of Australia (converted).svg  Australia
Extent Eromanga & Surat Basins

The Rolling Downs Group is a stratigraphic group present in the Eromanga and Surat Basins in eastern Australia, [1] which was deposited between the mid Barremian to early Turonian of the Cretaceous period. It primarily consists of nearshore shallow marine sediments deposited in the Eromanga Sea, though the uppermost and terminal members, the Winton Formation and the Griman Creek Formation represents freshwater deposits. It is notable for its fossil content including many dinosaurs and mammals, as well as opal. A relict species of dicynodont was suggested to have been found in these rocks, [2] but is more likely to be misidentified pieces of a Cenozoic marsupial from younger sediments. [3]

Related Research Articles

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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, typically toothless beak, unique amongst all synapsids. Dicynodonts first appeared in Southern Pangaea during the mid-Permian, ca. 270–260 million years ago, and became globally distributed and the dominant herbivorous animals in the Late Permian, ca. 260–252 Mya. They were devastated by the end-Permian Extinction that wiped out most other therapsids ca. 252 Mya. They rebounded during the Triassic but died out towards the end of that period. They were the most successful and diverse of the non-mammalian therapsids, with over 70 genera known, varying from rat-sized burrowers to elephant-sized browsers.

<i>Placerias</i> Extinct genus of dicynodonts

Placerias is an extinct genus of dicynodonts that lived during the Carnian to the Norian age of the Triassic Period. Placerias belongs to a group of dicynodonts called Kannemeyeriiformes, which was the last known group of dicynodonts before the taxon became extinct at the end of the Triassic.

<span class="mw-page-title-main">South Polar region of the Cretaceous</span> Animals that lived below the Antarctic circle in the Cretaceous

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<i>Daptocephalus</i> Assemblage Zone

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<i>Pristerognathus</i> Assemblage Zone

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<i>Tropidostoma</i> Assemblage Zone

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<span class="mw-page-title-main">Winton Formation</span> Geological formation in Australia

The Winton Formation is a Cretaceous 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 sedimentary rocks such as sandstone, siltstone and claystone. The sediments that make up these rocks represent the remnants of the river plains that filled the basin left by the Eromanga Sea - an inland sea that covered large parts of Queensland and central Australia at least four times during the Early Cretaceous. Great meandering rivers, forest pools and swamps, creeks, lakes and coastal estuaries all left behind different types of sediment.

<i>Cratochelone</i> Extinct genus of turtles

Cratochelone is an extinct genus of sea turtle in the family Protostegidae and containing a single species Cratochelone berneyi. The species is known only from the mid to late Albian Toolebuc Formation, part of the Rolling Downs Group, in the Hughenden of Central northern Queensland, Australia.

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<span class="mw-page-title-main">Wonthaggi Formation</span>

The Wonthaggi Formation is an informal geological formation in Victoria, Australia whose strata date back to the Early Cretaceous. It is part of the Strzelecki Group within the Gippsland Basin. Dinosaur remains are among the fossils that have been recovered from the formation. It is partially equivalent to the Eumeralla Formation.

The Wallumbilla Formation is an Aptian geologic formation found in Australia. Plesiosaur and theropod remains are among the fossils that have been recovered from its strata.

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<span class="mw-page-title-main">Geology of Queensland</span>

The geology of Queensland can be subdivided into several regions with different histories. Along the east coast is a complex of Palaezoic to Cainozoic rocks while much of the rest of the state is covered by Cretaceous and Cainozoic rocks. A Precambrian basement is found in the north west and Cape York regions. The Thomson Orogen occurs in the central and southern parts of Queensland, but is mostly covered by younger basins.

<span class="mw-page-title-main">Australian Age of Dinosaurs</span> Museum of Natural History in Winton, Queensland

Australian Age of Dinosaurs Ltd. (AAOD) is a nonprofit organization located in Winton, Queensland, founded by David Elliott and Judy Elliott in 2002. The organization’s activities include the operation of the Australian Age of Dinosaurs Museum of Natural History, which holds annual dinosaur digs in the Winton Formation of Western Queensland and oversees the year-round operation of Australia's most productive dinosaur fossil preparation laboratory. Since 2005, the AAOD Museum has accumulated the largest collection of Australian dinosaur fossils in the world and holds the holotype specimens of Diamantinasaurus matildae ("Matilda"), Savannasaurus elliottorum ("Wade"), Australovenator wintonensis ("Banjo"), Australia's most complete theropod skeleton, Ferrodraco lentoni, the first pterosaur to be named from the Winton Formation, and Confractosuchus sauroktonos. The museum is open to the public daily from April to October and is open six days a week from November to March. The site of the museum was designated a dark-sky preserve, the first International Dark-Sky Sanctuary in Australia, in 2019.

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.

References

  1. "Rolling Downs Group". Australian Stratigraphic Units Database. Geoscience Australia and Australian Stratigraphy Commission. Retrieved 20 August 2018.
  2. Thulborn, Tony; Turner, Susan (2003-05-07). "The last dicynodont: an Australian Cretaceous relict". Proceedings of the Royal Society of London B: Biological Sciences. 270 (1518): 985–993. doi:10.1098/rspb.2002.2296. ISSN   0962-8452. PMC   1691326 . PMID   12803915.
  3. Knutsen, Espen M.; Oerlemans, Emma (September 2019). "The last dicynodont? Re-assessing the taxonomic and temporal relationships of a contentious Australian fossil". Gondwana Research. 77: 184–203. doi:10.1016/j.gr.2019.07.011.