The Evergreen Formation is a Pliensbachian to Toarcian geologic formation of the Surat Basin in New South Wales and Queensland, eastern Australia. Traditionally it has been considered to be a unit whose age has been calculated in between the Pliensbachian and Toarcian stages of the Early Jurassic, with some layers suggested to reach the Aalenian stage of the Middle Jurassic, yet modern data has found that an Early Pliensbachian to Latest Toarcian age is more possible.[4][5][6] The formation was named due to the "Evergreen Shales", defined with a lower unit, the Boxvale Sandstone, and a partially coeval, partially younger upper unit, the Westgrove Ironstone Member.[7] This unit overlies the Hettangian-SinemurianPrecipice Sandstone, as well several informal units such as the Nogo Beds, and Narayen beds, as well Torsdale Volcanics.[7] This unit likely was deposited in a massive lacustrine body with possible marine environment influences.[8]
Fossil content
Indeterminate Unionoid bivalves are know from the Kolane Station.[9]
Marine-Mangroove Vertical, U-shaped, single-spreite Burrows; unidirectional or bidirectional spreite, generally continuous, rarely discontinuous. Most Diplocraterion show only protrusive spreiten, like the local ones, produced under predominantly erosive conditions where the organism was constantly burrowing deeper into the substrate as sediment was eroded from the top.
Cylindrical or elliptical curved/tortuous trace fossils
Polychaetes
Insects
Freshwater/Blackish burrow-like ichnofossils. Planolites is really common in all types of the Ciechocinek Formation deposits. It is referred to vermiform deposit-feeders, mainly Polychaetes, producing active Fodinichnia. It is controversial, since is considered a strictly a junior synonym of Palaeophycus.
Blackish trace ichnofossils. Interpreted as dwelling structures of vermiform animals, more concretely the Domichnion of a suspension-feeding Worm or Phoronidan.
Blackish trace ichnofossils. Interpreted as dwelling structures of vermiform animals, more concretely the Domichnion of a suspension-feeding Worm or Phoronidan.
Freshwater/Blackish burrow-like ichnofossils. Taenidium is a meniscate backfill structure, usually considered to be produced by an animal progressing axially through the sediment and depositing alternating packets of differently constituted sediment behind it as it moves forward.
Burrow-like ichnofossils. Large burrow-systems consisting of smooth-walled, essentially cylindrical components. Common sedimentary features are Thalassinoides trace fossils in the fissile marlstone to claystone intervals
Thalassinoides burrowing structures, with modern related fauna, showing the ecological convergence and the variety of animals that left this Ichnogenus.
Saltwater/Blackish burrow-like ichnofossils. The overall morphology and details of the burrows, in comparison with modern analogues and neoichnological experiments, suggest Echiurans (spoon worms) or Holothurians (sea cucumbers) with a combined suspension- and deposit-feeding behaviour as potential producers.
QM F7822, nearly complete skull with mandible and postcrania
A gigantic chigutisauridtemnospondyl, representing a relictual genus isolated in the Australian Ecoregion, as well one of the largest Mesozoic amphibians
Affinities with the family Sphagnaceae in the Sphagnopsida. "Peat moss" spores, related to genera such as Sphagnum that can store large amounts of water.
Affinities with the Selaginellaceae in the Lycopsida. Herbaceous lycophyte flora, similar to ferns, found in humid settings. This family of spores are also the most diverse in the formation.
Affinities with the genus Saccoloma, type representative of the family Saccolomataceae. This fern spore resembles those of the living genus Saccoloma, being probably from a pantropical genus found in wet, shaded forest areas.
Extant Saccoloma specimens; Annulispora probably comes from similar genera or maybe a species in the genus
Affinities with the families Peltaspermaceae, Corystospermaceae or Umkomasiaceae in the Peltaspermales. Pollen of uncertain provenance that can be derived from any of the members of the Peltaspermales. The lack of distinctive characters and poor conservation make this pollen difficult to classify. Arboreal to arbustive seed ferns.
From the family Caytoniaceae in the Caytoniales. Caytoniaceae are a complex group of Mesozoic fossil floras that may be related to both Peltaspermales and Ginkgoaceae.
Affinities with the family Cupressaceae in the Pinopsida. Pollen that resembles that of extant genera such as the genus Actinostrobus and Austrocedrus, probably derived from dry environments.
Affinities with the family Podocarpaceae. Pollen from diverse types of Podocarpaceous conifers, that include morphotypes similar to the low arbustive Microcachrys and the medium arbustive Lepidothamnus, likely linked with Upland settings
^Todd, Christopher N.; Roberts, Eric M.; Knutsen, Espen M.; Rozefelds, Andrew C.; Huang, Hui-Qing; Spandler, Carl (December 2019). "Refined age and geological context of two of Australia's most important Jurassic vertebrate taxa (Rhoetosaurus brownei and Siderops kehli), Queensland". Gondwana Research. 76: 19–25. Bibcode:2019GondR..76...19T. doi:10.1016/j.gr.2019.05.008.
^ abcdefghijklmnopqrstuvwxyPaten, R.J. (1967). "Microfloral distribution in the Lower Jurassic Evergreen Formation of the Boxvale area, Surat Basin,Queensland". Queensland Government Mining Journal. 68 (79): 345–349.