Fossil Flora of Australia

Abstract

THIS work is a translation from the author's older work in the “Palæontographica,” amended to 1887, edited by R. Etheridge, Jun., Government Palæontologist, and with notes by the Geological Surveyor-in-charge. The greatest development of the older beds occurs in New South Wales, where the coals, sandstones, and shales with plant impressions, are intercalated with porphyries to the thickness of 14,000 feet. Two remarkable facts give special interest to the beds: one is that under beds with Conularia, Spirifer, and Productus, believed to be Upper Carboniferous, certain plants of Mesozoic type appear; and the other, that just under these plant beds there are conglomerates regarded as having been deposited by the action of ice. The formations in New South Wales, Queensland, Victoria, and Tasmania, are described separately, but together they form a series; commencing with the Devonian Goonoo Goonoo, containing Lepidodendron; the Lower Carboniferous Lepidodendron beds; the Boulder beds, showing signs of glacial action, correlated with the similar Dwyka Conglomerate of Africa, and the Talchir Boulder bed of India; the lower marine beds of Upper Carboniferous age, followed by coal measures with Glossopteris, and an upper marine series; the Permian Newcastle beds with Glossopteris and heterocercal fish; the Hawkesbury Trias with Labyrinthodonts; and lastly some beds of Jurassic age. Until the base of the Upper Carboniferous is reached there is nothing abnormal, but at this point occur the remarkable intercalations of glaciated conglomerates, of which we have some slight indications in our English Permian, and which stretch both to India and Africa. This climatic change killed off the Lepidodendrons, and introduced a new flora containing the wide-spread Glossopteris and its ally Gangamopteris, and Nöggerathiopsis, types which would in Europe appear more at home in the Rhætic than in the Carboniferous, and which followed the changing climate as it spread to other continents. Meanwhile, the Carboniferous fauna of the seas is unaffected, and heterocercal fish accompany plants of quite Jurassic character in the Permian. This mingling of newer land floras with older marine faunas seems so universal in extra-European geology, particularly in America, that it appears as if during period after period the development of marine life was especially forced or quickened in the area which is now Europe, while terrestrial plant life was retarded, especially in England. The genera Glossopteris, Gangamopteris, and Nöggerathiopsis do not extend up beyond the Permian in Australia. In India Glossopteris is rare in the Jurassic, but its recorded extension into the Cretaceous of Russia must be questionable, while its supposed occurrence in the Tertiary of Novale is certainly due to its having been confused with the common Tertiary, and still existing, Chrysodium aureum, identical with it in venation but quite different in fruiting. In addition to these, the most noteworthy species are the beautiful adiantoid Rhacopteris of the Lower Carboniferous, to which several plates are devoted, and the Osmunda-like Thinnfeldia of the Mesozoic. The flora of the latter is only remarkable for its very European facies, and is said to include a Jurassic Sequoia, Cunninghamites, Baiera, Walchia, Taxites, and several Cycadeaceæ; it also shares with the Permian the fine Brachyphyllum australe, Feistm. There are altogether about 129 species or varieties described, of which about 50 are illustrated, and the volume is certainly a valuable contribution to the history of plant distribution. On the Coal and Plant-bearing Beds of Palæozoic and Mesozoic Age in Eastern Australia and Tasmania; with Special Reference to the Fossil Flora. By B. O. Feistmantel. Memoirs of the Geological Survey of New South Wales, 1890. (Sydney: Charles Potter, Government Printer.)