The Yarrol Province in eastern-central Queensland contains rocks ranging from latest Silurian to Permian. Devonian corals are locally abundant within the Yarrol Province, but their preservation is typically poor compared to the well-known Carboniferous coral faunas of this Province. Whilst deposition began in the Yarrol Province in the latest Silurian, the oldest corals found are Early Devonian. Except for the Mount Etna coral fauna, the Devonian corals had not been systematically described.
There are five, major, latest Silurian to Middle Devonian geological units recognised. These are the Late Silurian to Middle Devonian Erebus beds and Craigilee beds, Early Devonian Calliope beds, Early? to Middle Devonian Capella Creek Group (containing the Mount Dick beds, Mount Warner Volcanic and Raspberry Creek Formation, with its Ginger Creek Member), and the Middle Devonian (Givetian) Marble Waterhole beds. All of these five units have produced corals. Most of the corals from the Capella Creek Group are from the Middle Devonian (Eifelian to Givetian) Raspberry Creek Formation, with only rare occurrences in the Middle Devonian (Eifelian) Mount Warner Volcanics, and none in the Mount Dick beds which is lowest unit of the Capella Creek Group. On the basis of differences in rock types, stratigraphy, geochemistry and geophysics, the latest Silurian to Middle Devonian units have been placed into three tectono-stratigraphic assemblages. From east to west, the Calliope beds is placed in the Calliope Tectono-Stratigraphic Assemblage; the Erebus beds is placed in the Erebus Tectono-Stratigraphic Assemblage; and the Craigilee beds, Capella Creek Group and Marble Waterhole beds are placed in the Mount Morgan Tectono-Stratigraphic Assemblage.
The Late Devonian to earliest Carboniferous strata of the Yarrol Province are split into seven units: Mount Hoopbound Formation, Balaclava Formation, Lochenbar Formation, Three Moon Conglomerate, Mount Alma Formation, Yarwun beds, and Channer Creek beds . These geological units are interpreted as part of the Bindawalla Tectono-Stratigraphic Assemblage. Fossil corals have been collected from all these units except for the Balaclava Formation and the Yarwun beds. All the corals collected from these units appear to be restricted to the Frasnian, with no Famennian or Early Carboniferous corals found. In the Three Moon Conglomerate and Mount Alma Formation, the corals were only found as clasts in mass-flow conglomerates. Only two coral specimens were collected from the Mount Alma Formation. Although fossil bearing conglomerates were found in only a few places within the Three Moon Conglomerate, a large number of specimens and species were collected. Fossil corals were sparse in the Mount Hoopbound Formation and the Channer Creek beds. A large number of specimens and species were recovered from the shallow marine Lochenbar Formation.
Mapping of the Bindawalla Tectono-Stratigraphic Assemblage has identified a large number of allochthonous limestone blocks. Coral faunas have been collected from several of these limestone masses, and the corals indicate that limestones of both Early and Middle Devonian age have been eroded from the older tectono-stratigraphic assemblages.
The taxonomic study of all pre-existing collections, and the extensive collections made during the recent stratigraphic mapping of the province, has identified 78 species of rugose and tabulate corals belonging to 43 genera.
Forty-three species were referred to previously described taxa: Tryplasma wellingtonensis Etheridge, 1907, Rhizophyllum parvum Strusz, 1970, Microplasma caespitosum (Schluter, 1882), Microplasma ronense (Mansuy, 1913), Pseudomicroplasma australe (Etheridge, 1892), Pseudamplexus princeps (Etheridge, 1907), Barrandeophyllum cavum Hill, 1954, Endophyllum columna columna (Hill, 1942), Blysmatophyllum multigemme Zhen, 1994, Mictocystis sp. cf. M. endophylloides Etheridge, 1908, Sanidophyllum davidis Etheridge, 1899, Tabulophyllum abrogatum (Hill, 1942), Acanthophyllum (Acanthophyllum) clermontense (Etheridge, 1911), Dohmophyllum clarkei Hill, 1942, Grypophyllum jenkinsi Strusz, 1966, Xystriphyllum insigne Hill, 1940, Xystriphyllum sp. cf. X. magnum Hill , 1942, Stringophyllum bipartitum Hill, 1942, Stringophyllum quasinormale Hill, 1942, Columnaria jenkinsi Wright, 1990, Disphyllum caespitosum (Goldfuss, 1826), Amaraphyllum amoenum Pedder, 1970, Argutastrea hullensis (Hill, 1954), Chalcidophyllum gigas Pedder, 1972, Chostophyllum gregorii (Etheridge, 1892), Piceaphyllum menyouense (Hill & Jell, 1971), Temnophyllum turbinatum Hill, 1954, Phillipsastrea carinata Hill, 1942, Favosites careyi Jell & Hill, 1970, Favosites duni Etheridge, 1920, Favosites forbesi Milne-Edwards & Haime, 1851 , Favosites goldfussi d' Orbigny, 1850, Favosites gothlandicus Lamarck, 1816, Favosites grandipora Etheridge, 1890, Squameofavosites bryani (Jones, 1937), Squameofavosites nitidus (Chapman, 1914), Thamnopora boloniensis (Gosselet, 1877), Alveolites caudatus Hill, 1954, Alveolites suborbicularis Lamarck, 1801, Heliolites daintreei Nicholson & Etheridge, 1879, Heliolites porosa (Goldfuss, 1826), Romingeria sp. cf. R. emergens (Quenstedt, 1881) , and Syringopora jonesi Jell & Hill, 1970.
There are 34 new species , of which, 20 have been named: Tryplasma careoseptis, Tryplasma abyssis, Aphyllum simplexum, Cystiphylloides magnusis, Breviphyllum mirourum, Smithiphyllum petercollsi, Smithiphyllum finseni, Tabulophyllum tholusum, Solipetra margaritatus, Papiliophyllum jelli, Disphyllum castellum, Disphyllum stupendum, Temnophyllum kroombitensis, Temnophyllum stainesi, Phillipsastrea maceria, Squameofavosites craigileei, Alveolites murrayi, Heliolites amplusa, Heliolites comminus, and Multithecopora tubus; and 14 species have been left in open nomenclature: Breviphyllum sp. nov. A, Metriophyllum? sp. nov . A, Tabulophyllum sp. nov. A, Dohmophyllum sp. nov. A, Embolophyllum sp. nov. A, Papiliophyllum sp. nov. A, Charactophyllum sp. nov. A, Charactophyllum sp. nov. B, Temnophyllum sp. nov. A, Phillipsastrea sp. nov. A, Thamnophyllum sp. nov. A., Favosites sp. nov. A, Favosites sp. nov. B, and Multithecopora sp. nov. A.
The rugose coral genus Calceola was recorded, but no specimens were found that were suitable for collection, therefore its species is left in open nomenclature.
The coral species have been assigned to six coral faunas. Three of the faunas, the Favosites, Papiliophyllum, and Tryplasma Faunas are from the Early Devonian. The Favosites Fauna is interpreted as Pragian, and the Papiliophyllum and Tryplasma Faunas are both considered as early Emsian. The Phillipsastrea and Amaraphyllum Faunas are from the Middle Devonian, and the former is interpreted as Eifelian, and the Amaraphyllum Fauna Givetian. The youngest Devonian fauna, the Temnophyllum Fauna, is Late Devonian, spanning much of the Frasnian.
The Early and Middle Devonian coral faunas are most similar to coral faunas in Asia, with lesser similarities to the coral faunas of North America and Europe. This is consistent with the finding of other researchers, and supports the tectonic model of Australia occupying the northeastern seaboard of Gondwana with the North China and South China Blocks proximally located to the northwest. The Late Devonian coral fauna is unusual, in that it is more similar to the distal European and North American coral faunas than the more proximal Asian faunas.
The Early Devonian coral faunas delineated in this thesis correlate with the Tectono-Stratigraphic Assemblages proposed by the Geological Survey of Queensland during their re-mapping of the Yarrol Province during the mid to late 1990s . The Favosites Fauna is confined to the Calliope Tectono-Stratigraphic Assemblage; the Papiliophyllum Fauna to the Erebus Tectono-Stratigraphic Assemblage, and the Tryplasma Fauna to the Mount Morgan Tectono-Stratigraphic Assemblage. The contrast in the geology and the coral faunas of the three Late Silurian to Middle Devonian tectono-stratigraphic assemblages supports the tectonic model that interprets these assemblages as representing separate oceanic arcs.
As there does not appear to be any differentiation in the geological history nor the coral faunas of the Late Devonian geological units, they are considered a single, widespread tectono-stratigraphic assemblage, the Bindawalla Tectono-Stratigraphic Assemblage.