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
RegionNew South Wales
Queensland
South Australia
CountryAustralia
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]

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.