An Australian origin for the candle nut (Aleurites, Crotonoideae, Euphorbiaceae) and the fossil record of the Euphorbiaceae and related families in Australia and New Zealand

A fossil seed from south east Queensland referable to the extant genus Aleurites (candlenut) is described as a new species, A. australis, and is one of the few macrofossil records of Euphorbiaceae from Australia. The new fossil data and phylogenetic studies of the biogeographical relationships of Aleurites based upon analysis of rbcL and trnL-F sequence data support a Gondwanic origin for the clade. The macrofossil record of Euphorbiaceae in Australia is restricted to seeds of Aleurites; and fruits of Fontainocarpa which are thought to have affinities with Fontainea, and both extant genera are referable to the Crotonoideae. One group of crotonoids has inaperturate spheroidal pollen, that is comparable to the dispersed pollen genus, Crotonipollis, which has an Oligocene to Recent range in Australia. The fossil pollen record in Australia and New Zealand of other Euphorbiaceae and related families includes species of Malvacipollis that have affinities to the Picrodendraceae; Nyssapollenites endobalteus (McIntyre) Kemp and Harris has affinities with the subfamily Acalyphoideae (Euphorbiaceae); and putative records of Homalanthus suggest affinities with the subfamily Euphorbioideae (Euphorbiaceae). Fossil fruits of Glochidion provide possible evidence of the Phyllanthaceae. The stratigraphic range of these taxa in respect to the Weddellian Biostratigraphic Province, which includes southern South America, western Antarctica, New Zealand, and eastern Australia is also briefly reviewed

A Lagerstätte from Australia provides insight into the nature of Miocene mesic ecosystems

Reduced precipitation in the Miocene triggered the geographic contraction of rainforest ecosystems around the world. In Australia, this change was particularly pronounced; mesic rainforest ecosystems that once dominated the landscape transformed into the shrublands, grasslands, and deserts of today. A lack of well-preserved fossils has made it difficult to understand the nature of Australian ecosystems before the aridification. Here, we report on an exceptionally well-preserved rainforest biota from New South Wales, Australia. This Konservat-Lagerstätte hosts a rich diversity of microfossils, plants, insects, spiders, and vertebrate remains preserved in goethite. We document evidence for several species interactions including predation, parasitism, and pollination. The fossils are indicative of an oxbow lake in a mesic rainforest and suggest that rainforest distributions have shifted since the Miocene. The variety of fossils preserved, together with high fidelity of preservation, allows for unprecedented insights into the mesic ecosystems that dominated Australia during the Miocene

The first Australian palynologist: Isabel Clifton Cookson (1893–1973) and her scientific work

Isabel Clifton Cookson (1893–1973) of Melbourne, Australia, was one of that country’s first professional woman scientists. She is remembered as one of the most eminent palaeontologists of the twentieth century and had a distinguished research career of 58 years, authoring or co-authoring 93 scientific publications. Isabel worked with great distinction on modern and fossil plants, and pioneered palynology in Australia. She was a consumate taxonomist and described, or jointly described, a prodigious total of 110 genera, 557 species and 32 subspecific taxa of palynomorphs and plants. Cookson was a trained biologist and initially worked as a botanist during the 1920s. At the same time she became interested in fossil plants and then, Mesozoic–Cenozoic terrestrial (1940s–1950s) and aquatic (1950s–1970s) palynomorphs. Cookson’s research into the late Silurian–Early Devonian plants of Australia and Europe, particularly the Baragwanathia flora, between the 1920s and the 1940s was highly influential in the field of early plant evolution. The fossil plant genus Cooksonia was named for Isabel in 1937 by her principal mentor in palaeobotany, Professor William H. Lang. From the 1940s Cookson focussed on Cenozoic floras and, with her students, elucidated floral affinities by comparative analyses of micromorphology, anatomy and in situ pollen/spores between fossil and extant taxa. This led to an interest in pre-Quaternary and Quaternary terrestrial pollen and spores; hence Isabel was the first palynologist in Australia. Her work on Paleogene and Neogene pollen and spores during the 1940s and 1950s provided incontrovertible evidence of the former widespread distribution of many important elements of Southern Hemisphere floras. During the early 1950s, while approaching her 60th year, Isabel turned her attention to marine palynomorphs. She worked with great distinction with Georges Deflandre and Alfred Eisenack, and also as a sole author, on acritarchs, dinoflagellate cysts and prasinophytes from the Jurassic to Quaternary of Australia and Papua New Guinea. She also co-authored papers on aquatic palynomorphs with Lucy M. Cranwell, Norman F. Hughes and Svein B. Manum. Isabel Cookson laid out the taxonomic basis for the study of Australasian Mesozoic and Cenozoic marine palynofloras by establishing, or jointly establishing, 76 genera and 386 species of marine microplankton. Her studies throughout her career, although especially in marine palynology, concentrated largely on taxonomy. However, she was one of the first palynologists to demonstrate the utility of dinoflagellate cysts for relative age dating and correlation in geological exploration

Patterns of vegetational change through the Late Mesozoic in southern Gondwana

Near the close of the Triassic the Dicroidum flora of Gondwanan regions underwent considerable modification involving replacement of several corystosperms, podocarp conifers and seed ferns (eg., Dicrodium, Linguifolium, Heidiphyllum) by newly evolved taxa of the Bennittitales, Caytoniales, and cheirolepidacean conifers. Floral turnover was accompanied by profound faunal modifications that included proliferation of dinosaurs and turnover of invertebrate taxa in the marine realm. The macrofloral and palynofloral record reveals that the Gondwanan Early Jurassic flora reflects a more cosmopolitan aspect than that of the Triassic, but the Gondwanan character was retained by several notable endemics (eg. pentoxylaleans, araucarians). Moreover, the fossil plant record implies that there was floral regionalism between peripheral (South America, eastern Australia) and inland (Western Australia, eastern Antarctica, India, Madagascar) areas of Gondwana. Regionalism within the vegetation of southern Gondwana became more pronounced during the Middle and Late Jurassic and accelerated during the Cretaceous when angiosperms entered mid-high southern latitudes. By the close of the Cretaceous southern Gondwanan vegetation was strongly regionalised not only across the latitudes, but also within the same latitudinal belt. Causative mechanisms appear to be related to environmental and climatic perturbations resulting from volcanic and tectonic activity concurrent with rifting, drifting, and opening of oceans. Patterns of vegetational change and of strengthening floral regionalism through the Late Mesozoic in southern mid-high latitudes are discussed with reference to progressive fragmentation of the Gondwanan assembly

First record from Australia of the Cretaceous fern genus Tempskya and the description of a new species, T judithae

Silicified fragments of false-trunks of the fern, Tempskya judithae sp. nov., are described from lower Cretaceous (latest Albian) sediments near Winton, central-western Queensland. The species is characterised by a three-layered sclerenchymatous cortex and a two-layered pith of sclerenchyma cells. In possessing these characters, T judithae is more similar to T readii than to other species of Tempskya. However, the Australian species differs from T readii in the abaxial shape of the petiole xylem trace (concave in T judithae, convex in T readii) and in symmetry attributes of the leaf-bases within the false-trunk (random in T judithae and radially symmetrical in T readii). T judithae is the first record of Tempskya from Australia and the second from Gondwana; the known distribution range of the genus embraces a broad area in mid-high latitudinal regions of Laurasia and the Gondwana record now comprises Australia and Argentina. Ecological signals of plant fossil assemblages recorded from the Australian sediments are in accord with flood plain habitats and a temperate climatic regime. (c) 2004 Elsevier B.V. All rights reserved

Monocotyledon fruits and seeds, and an associated palynoflora from Eocene-Oligocene sediments of coastal central Queensland, Australia

Fruits of Restionaceae and seeds of Typhaceae are described from a latest Eocene-Oligocene mudstone underlying oil shales in a subsurface sequence near Rockhampton, coastal central Queensland. The Restionaceae fruits are unilocular and encase a single pendulous orthotropous seed with a structured micropylar cap, which may be tannin filled. These are allocated to Restiocarpum gen. nov., which has as its type Restiocarpum latericum sp. nov., and four other taxa described herein; Restiocarpum tesselatum sp. nov., Restiocarpum, verrucatum sp. nov., Restiocarpum laeve sp. nov., and Restiocarpum fusiforme sp. nov. Typhaspermum,I cooksoniae gen. et sp. nov., which accommodates asymmetric claviform seeds, is interpreted as a member of the Typhaceae based on the presence of a lid-like operculum, bitegmic wall, and chalazal cavity. Reconstruction of the source plant community emphasizes similarities to restiad swamps of present day Wallum (swamp heathland) vegetation which is extensively developed along the Queensland coast. Biogeographic implications for the Restionaceae and Typhaceae are discussed. (C) 2000 Elsevier Science B.V. All rights reserved

Structure and form ofaustral Cretaceous Normapolles-like pollen

Detailed analysis of breviaxial, tricolporate pollen from the Australian Upper Cretaceous reveals that Forcipites Dettmann & Jarzen, 1988, Gambierina Harris ex Stover & Partridge, 1973, emend., and Battenipollis gen. nov. are distinct in wall structure and aperture architecture from the Normapolles and Probrevaxones of the Northern Hemisphere. The parental source of the southern Normapolles-like pollen ranged across the Austro-Antarctic landmass during latest Cretaceous time, but probably evolved later than and independently of the northern taxa. Battenipollis is proposed for transcolpate, breviaxial pollen, and Gambierina is herein emended

The Antarctic/Australian rift valley: Late cretaceous cradle of nortteastern Australasian relicts?

The montane vegetation of northeastern Australasia represents a modified sample of the late Cretaceous flora that fringed the embryonic Southern Ocean in the southern Australasian/Antarctic region. Beauprea, Knightia, Macadamia, Gevuina and/or Hicksbeachia (Proteasceae), Gunnera (Gunneraceae), Ilex (Aquifoliaceae), Winteraeae, Epacridaceae, Trimeniaceae, Nothofagus (brasii group), Araucariaceae, Podocorpus, Dacrydium and Dacrycarpus (Podocarpaceae) are confirmed in the Campanian-Maastrichtian pollen record of estuarine sediments in the Otway Basin, southeastern Australia. The primative angiosperms migrated there by individualistic routes after Early Cretaceous appearances in northern Gondwana and southern Laurasia; other taxa evolved in austral regions. Evidence is advanced for origin of Ilex, Beauprea, Knightia and Gevuina/Hicksbeachia in southern Australia/Antarctica during early phases (Late Cretaceous) of opening of the Southern Ocean

Miocene palynofloras from subsurface sediments in the Bundaberg district

Well-preserved palynofloras extracted from flavial sediments of the Cainozoic Elliott Formation in the Bundaberg Trough, central-eastern Queensland enable dating the formation, the age of which hitherto has been poorly constrained. Representation of the pollen taxon, Canthiumidites bellus (Stover & Partridge) Mildenhall & Pocknall, in association with spores referable to Polypodiidites usmensis (van der Hammen) Khan & Martin, both of which are restricted to Early Miocene and younger sediments in the Capricorn Basin, confirm an age no older than the Early Miocene, and enable correlation of the Bundaberg sequence with Early Miocene fluvio-deltaic sediments penetrated by GSQ Sandy Cape 1-3R on Fraser Island. Records of Polypodiidites usmensis in the Fairymead beds, which underlie the Elliott Formation, indicate that the Fairymead beds are also no older than Early Miocene. □ Elliott Formation, palynofloras, Miocene, Capricorn Basin