29 research outputs found

    Palaeontology, the biogeohistory of Victoria

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    The broad-scale distribution of fossils within Victoria is controlled by general global patterns in the biological evolution of life on Earth, the local development and environmental evolution of habitats, and the occurrence of geological processes conducive to the preservation of fossil floras and faunas. Early Palaeozoic fossils are mostly marine in origin because of the predominance of marine sedimentary rocks in Victoria and because life on land was not significant during most of this time interval. Middle Palaeozoic sequences have both terrestrial and marine fossil records. Within Victoria, marine rocks are only very minor components of strata deposited during the late Palaeozoic, so that few marine fossils are known from this time period. A similar situation existed during most of the Mesozoic except towards the end of this era when marine conditions began to prevail in the Bass Strait region. During long intervals in the Cainozoic, large areas of Victoria were flooded by shallow-marine seas, particularly in the southern basins of Bass Strait, as well as in the northwest of the State (Murray Basin). Cainozoic sediments contain an extraordinary range of animal and plant fossils. During the Quaternary, the landscape of Victoria became, and continues to be, dominated by continental environments including, at times, extensive freshwater lake systems. Fossil floras and faunas from sediments deposited in these lake systems and from other continental sediments, as well as from Quaternary sediments deposited in marginal marine environments, collectively record a history of rapid fluctuations in climate and sea level.<br /

    Carboniferous and Permian Rugosochonetidae (Brachiopoda) from West Spitsbergen

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    The rugosochonetid brachiopod species Lissochonetes geinitzianus from the Kazimovian of the Nordenskioldbreen Formation, and Dyoros (Dyoros) mucronata sp. nov., Dyoros (Dyoros) spitzbergianus and Lissochonetes superba from the Artinskian to latest Permian Kapp Starostin Formation in West Spitsbergen are described and figured. Dyoros is generally restricted to the Boreal Realm, whereas Lissochonetes is mostly distributed in the Boreal Realm, but occasionally present in the Palaeoequatorial and Gondwanan Realms<br /

    Permian Chonetoidea and Spiriferoidea of Australasia : Gondwanan relationships, provincialism, palaeobiogeography

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    Members of the Spiriferoidea are dominant in the Permian marine invertebrate faunas of Australia. Genera can be endemic to a particular province, demonstrate a wider Gondwanan and peri-Gondwanan distribution and several indicate a bipolar distribution. Australasian spiriferoids are included within the families Spiriferidae, Neospiriferidae, Trigonotretidae and the Spiriferellidae. Several genera and species are the largest spirferoids ever recorded. Few genera are shared between the Westralian and Austrazean provinces but a higher proportion of genera are shared between the Westralian province and the Cimmerian Realm.Representatives of the Chonetoidea are a less common but significant element of the faunas. They were used over 20 years ago to define the Westralian and Austrazean provinces of Australasia &ndash; concepts that are in widespread use today. The Paratinan and Cimmerian provinces were also defined at that time despite difficulties in their definition. Through more recent studies the Cimmerian Province has been upgraded to a Realm while the Paratinan Province is more clearly defined for the earliest Permian, based on the chonetoids of Patagonia and western and eastern central Argentina.Distribution of the various genera is best explained by an interplay of factors including surface and deeper oceanic currents, marine water temperatures and tectonic events such as the clockwise rotation of Gondwanan and the dispersal of the peri-Gondwanan Cimmerian terranes. Austrazean faunas developed in isolation under the influence of cooler and cold waters during the early Permian. Late Permian faunas demonstrated more widespread linkages.<br /

    An early occurrence of Sarcophilus laniarius harrisii (Marsupialia, Dasyuridae) from the early Pleistocene of Nelson Bay, Victoria

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    The isolated lower molar series of a dasyurid from early Pleistocene sediments at Nelson Bay, near Portland, is referred herein to Sarcophilus laniarius harrisii (Boitard, 1842). Dental measurements and morphological comparisons taken from this tooth series compare closely with those of the extant subspecies. The genus Sarcophilus is known from the early Pleistocene by the species S. moornaensis Crabb 1982. Fossil material assigned to S. laniarius harrisii is now also known from Early Pleistocene sediments. The new specimens from Nelson Bay extend the origin of S. laniarius harrisii to the early Pleistocene.<br /

    Glaucodon Ballaratensis (Marsupialia, Dasyridae), a late Pliocene \u27Devil\u27 from Batesford, Victoria

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    The right mandible of a dasyurid from Pliocene sediments at Batesford, near Geelong, Victoria is described as a new specimen of Glaucodon ballaratensis Stirton, 1957. The new specimen is morphologically close to the holotype of Glaucodon ballaratensis. Several dental characteristics of the new specimen unknown from the holotype of Glaucodon ballaratensis are close to those of Sarcophilus moornaensis Crabb, 1982. Glaucodon ballaratensis also shares features with Dasyurus maculatus Kerr, 1792 and Sarcophilus laniarius harrisii Boitard, 1842, and hence the Batesford specimen offers additional information on the origins of these dasyurids.<br /

    Reworked Devonian (Givetian-Frasnian) spores from a Permian glacially-derived sequence at Bacchus Marsh, Victoria

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    Emphanisporites rotatus McGregor emend. McGregor 1973 is a distinctive Devonian spore with a known primary source age range in Australia spanning the upper Givetian to early Frasnian (Middle to Late Devonian). This is the first record of the species from Victoria. It occurs as a reworked element in an Early Permian assemblage belonging to the Granularisporites confluens Zone derived from glacigene diamictite in the Bacchus Marsh area. As the predominant direction of Permian ice movement recorded in the Bacchus Marsh district was south-west to north-east, it is possible that the reworked spores were transported from Antarctica.<br /
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