Fossil megafloras obtained from the Jurassic Walloon Coal Measures (and correlatives) of the Clarence Moreton, Surat, and Mulgildie Basins of Queensland comprise at least 33 species distributed among the Bryophyta(?), Arthrophyta, Pterophyta, and gymnosperms. The Coniferophjrba are dominant; Ginkgophyta are conspicuously absent. Representatives of the Hepatieae(?), Equisetaceae, and Osmundaceae are treated in detail. The genera "Thallites Walton 1925", Eauisetum Linnaeus 1753, and Osmundacaulis Miller 1967 are discussed, "Thallites" sp., Equisetum laterale Phillips 1829 emend., E. bryanii sp. nov., Osmundacaulis dunlopi (Kidston & Gwynne-Vaughan) Miller 1967, O. sahnii (Vishnu-Mittre) Miller 1967, 0. hoskingii sp. nov. var, hoskingii. and O, hoskingii sp. nov. var. tabulatus var. nov. are described in detail. The significant features of O. gibbiana (Kidston & Gwynne-Vaughan) Miller 1967 are also documented. A table of morphological comparisons of all known Mesozoic species of Osmundacaulis is presented.
Stratigraphic data on the Walloon Coal Measures, their lithological equivalents, and associated rock units, are compiled. From floral, faunal, and stratigraphic evidence, it is considered that the Walloon Coal Measures are probably of Middle Jurassic age.