Papers by Anne-Marie Tosolini
Palaios, 2020
Floral Lagerstätten deposits (i.e., fossil sites with exceptional preservation and diversity) are... more Floral Lagerstätten deposits (i.e., fossil sites with exceptional preservation and diversity) are preserved within the Miocene brown coals of the Latrobe Group, Gippsland Basin, Australia. Three independent mechanisms are conducive to their accumulation. Throughout the coal seams the conversion of plant material into charcoal (fusain) and its accumulation in a subaqueous setting provides one means of near-perfect preservation. A second and more uncommon example occurs in the form of a 20 cm thick leaf-litter horizon that extends for over two kilometers. In this case, flooding of freshwater tributaries and lakes during the early stages of low-gradient peat development resulted in an extensive, shallow, acidic and water-filled depression that subsequently accumulated and preserved the surrounding plant material. The third and most common form results from the deposition of plant material into small, isolated pools that formed as depressions on the ombrogenous (i.e., rain-fed) and domed surface of the peatlands. In all of these settings an essential component allowing detailed floral preservation is the delivery of plant material directly to the anaerobic catotelm (i.e., below the water table), hence avoiding the physical and chemical processes of degradation that typically occur in the surficial aerobic acrotelm (i.e., above the water table). Leaf litter that falls into low-energy acidic and anoxic water-filled depressions that lie below the acrotelm will likely be well-preserved.
Palaeocene high-latitude leaf flora of Antarctica Part 2: Tooth-margined angiosperms
Review of Palaeobotany and Palynology
The late Palaeocene (Thanetian) Cross Valley Formation on Seymour Island is one of the few floras... more The late Palaeocene (Thanetian) Cross Valley Formation on Seymour Island is one of the few floras of this age in Antarctica. Understanding the diversity is critical for comparisons with coeval high-latitude forests and their evolution across South America and Australasia. This macroflora has few conifers and ferns but a significant diversity of angiosperms. Taxonomic assessment of previously undescribed morphotypes, based on new and existing collections, facilitated the identification of twelve new tooth-margined angiosperms of uncertain affinities. Comparisons to Gondwanan families already established in the Cross Valley Flora from pollen and wood records include Nothofagaceae, Proteaceae and Cunoniaceae. A total of 37 angiosperm taxa, including 23 tooth-margined and 14 entire-margined morphotypes, have been described from the Cross Valley Flora. They provide evidence that the most diverse Palaeocene floral assemblage recorded from this region inhabited the east side of the Antarctic Peninsula. The new morphotypes enrich the cool-temperate nature of the angiosperms that dominated over the conifers in these high-latitude forests. They indicate dynamic forests that responded to frequent disturbance as they grew on the slopes of active volcanoes; a physical divide that created a rainfall and climatic gradient from east to west across the Antarctic Peninsula. Floral elements, such as Proteaceae that indicates drier climates and Nothofagaceae that indicates cooler climates, signify that these forests were on the lee side of volcanoes on the Antarctic Peninsula. These forests represent extirpation and retraction of the Valdivian cool-temperate rainforests, which extended further south than their modern Patagonian distribution, in southern South America. Thus, the new morphotypes suggest additional floral diversity was present in the late Palaeocene and highlight the diversity contrast between the east and west Antarctic Peninsula.
Paleocene high-latitude leaf flora of Antarctica Part 1: entire-margined angiosperms
Review of Palaeobotany and Palynology, 2021
Abstract Paleocene leaf floras are rare in high latitudes of the Southern Hemisphere, where studi... more Abstract Paleocene leaf floras are rare in high latitudes of the Southern Hemisphere, where studies have shown higher taxonomic diversity compared to Northern Hemisphere equivalents. The floras provide valuable insights into biodiversity and forest communities during the Paleocene. The Antarctic Peninsula hosts a wealth of Paleocene–Eocene floras which have been used to interpret climates before, during and after one of the most abrupt and transient warming events known from the geological record. The best-preserved and most diverse Paleocene macrofossils from this region come from the Cross Valley Formation, Seymour Island Group, which have previously provided evidence for warm temperate climates prior to the PETM. Here we present the taxonomy of leaf impressions from the Paleocene Cross Valley Flora for one species and ten new leaf morphotypes of entire-margined angiosperms. The new morphotypes provide evidence of an increased angiosperm diversity within cool-temperate Gondwanan forest inhabiting the east side of the Antarctic Peninsula, which contrasts with a lower floral diversity on the west side of the Peninsula during the late Paleocene.
The Origin of Floral Lagerstätten in Coals
PALAIOS, 2020
Floral Lagerstätten deposits (i.e., fossil sites with exceptional preservation and diversity) are... more Floral Lagerstätten deposits (i.e., fossil sites with exceptional preservation and diversity) are preserved within the Miocene brown coals of the Latrobe Group, Gippsland Basin, Australia. Three independent mechanisms are conducive to their accumulation. Throughout the coal seams the conversion of plant material into charcoal (fusain) and its accumulation in a subaqueous setting provides one means of near-perfect preservation. A second and more uncommon example occurs in the form of a 20 cm thick leaf-litter horizon that extends for over two kilometers. In this case, flooding of freshwater tributaries and lakes during the early stages of low-gradient peat development resulted in an extensive, shallow, acidic and water-filled depression that subsequently accumulated and preserved the surrounding plant material. The third and most common form results from the deposition of plant material into small, isolated pools that formed as depressions on the ombrogenous (i.e., rain-fed) and dome...
Palaeoenvironments and palaeocommunities from Lower Cretaceous high-latitude sites, Otway Basin, southeastern Australia
Palaeogeography, Palaeoclimatology, Palaeoecology, 2018
Abstract Lower Cretaceous (Barremian to Albian) fossil plant assemblages are preserved in sedimen... more Abstract Lower Cretaceous (Barremian to Albian) fossil plant assemblages are preserved in sediments of the Otway Group, Otway Basin, and contemporaneous Strzelecki Group, Gippsland Basin, southeastern Australia. Detailed lithofacies and biofacies analyses of terrestrial strata within the upper Eumeralla Formation (Albian), Otway Group, allow fine-scale interpretation of braided fluvial and paludal depositional environments throughout the succession. The previously described flora is re-assessed in light of changes in depositional style and plant communities to describe six Albian biofacies. Forests in the highlands are dominated by Araucariaceae conifers, which turn over to Podocarpaceae and Cheirolepidiaceae forests on the dry, raised areas in the lowlands. Ferns and angiosperms inhabit the moist floodplains and water ferns and lycophytes dwell in the ox-bow lakes. Significant changes occur between floral communities characteristic of riparian, levee and floodbasin settings through the Early Cretaceous. Albian floras are characterized by the dominance of broad-leafed araucarian conifers, an understory of diverse ferns and a dearth of seedferns and angiosperms. There is a notable absence of macrofossil ginkgoaleans in the Eumeralla Formation, although they reappear in younger (Turonian) deposits in southeastern Australia, but angiosperms are extremely scarce as macrofossils compared to the diversity recently recorded in the pollen record. Abundant charcoal demonstrates that fire continued to be a significant environmental factor at high latitudes during the middle to late Albian. The discovery of dinoflagellate species supports an earlier marine incursion and increased coastal environments, probably inhabited by cheirolepids, across the Otway Basin. Palaeontological, palynological and sedimentological data has provided a synthesis of the region's warm, high-latitude, palaeoclimatic setting in the Albian stage of the Early Cretaceous when compared to the cooler Barremian to Aptian.
Cyclic floral succession and fire in a Cenozoic wetland/peatland system
Palaeogeography, Palaeoclimatology, Palaeoecology, 2016
Abstract The cyclic succession of brown coals in the Latrobe Valley, Gippsland Basin, Australia, ... more Abstract The cyclic succession of brown coals in the Latrobe Valley, Gippsland Basin, Australia, records an exceptional floral and charcoal record from the Late Oligocene to Middle Miocene. New palynological, geological and charcoal data are consistent with existing colourimetry, carbon isotope, and organic geochemical and palaeobotanical data, indicating that the repeated lithotype cycles represent relative drying (terrestrialization). Based on this detailed palynological study, the vegetation succession within the Latrobe Valley peatlands is interpreted to have begun with a fire-prone emergent marsh of bulrushes (Typhaceae), which grades landward into a fire-prone meadow marsh of rushes (Restionaceae), heaths (Ericaceae) and coral-ferns (Gleicheniaceae). This marsh environment then developed into a forested bog, with gymnosperms (e.g. the Podocarpaceae Dacrycarpus and Dacrydium ) as the dominant trees, until an ombrogenous forest bog developed, predominantly consisting of angiosperms (e.g. Nothofagus , Quintinia ). The similarity between vegetation successions in New Zealand and the lightening-upwards cycles from the Latrobe Valley coals suggests that New Zealand's modern vegetation communities represent a floral analogue for the successions preserved in the Latrobe Valley coals. High abundances of micro and macro charcoal recorded in the darker lithotypes, within the lithotype cycles of the M1B and M2A seams, suggest that the Latrobe Valley peatlands were subject to repeated fires during the Late Oligocene to Early Miocene.
Insights from a Continent in Transformation
Shallow water mud-mounds of the Early Devonian Buchan Group, East Gippsland, Australia
Sedimentary Geology, 2012
ABSTRACT The Lower Devonian Rocky Camp Member of the Murrindal Limestone, Buchan Group of southea... more ABSTRACT The Lower Devonian Rocky Camp Member of the Murrindal Limestone, Buchan Group of southeastern Australia consists of a series of carbonate mud-mounds and smaller lagoonal bioherms. The Rocky Camp mound is the best exposed of the mud-mounds and has many characteristics in common with Waulsortian (Carboniferous) mounds. Detailed paleoecological and sedimentological studies indicate that the mound initially accumulated in the photic zone, in contrast to most of the previously recorded mud-mounds. Five facies are present in the mud-mound: a Dasycladacean Wackestone Facies at the base of the mound represents a moderate energy, shallow water bank environment within the photic zone. A Crinioidal Wackestone Facies was deposited in a laterally equivalent foreslope setting. A Poriferan-Crinoidal Mudstone Facies developed in a quiet, deeper water, lee-side mound setting associated with a minor relative sea-level rise. A Stromatoporoid-Coralline Packstone Facies in the upper part of the mound deposited in a high-energy, fair-weather wave base, mound-front environment. The crest of the mound is represented by a Crinoidal-Receptaculitid Packstone Facies indicative of a moderate-energy mound-top environment in the photic zone, sheltered by the mound-front stromatoporoid-coral communities. A mound flank facies is present on the southern side of the mound and this consists of high-energy crinoidal grainstones. Mud-mound deposition was terminated by a transgression that deposited dark gray, fossil-poor marl of the overlying Taravale Formation.
Australian Journal of Earth Sciences, 1999
The stratigraphy of the onshore and offshore Gippsland Basin has been summarised by Haskell (1972... more The stratigraphy of the onshore and offshore Gippsland Basin has been summarised by Haskell (1972), James and Evans (1971), Thompson (1986) and Douglas (1988b). The Strzelecki Group represents the basal unit in the basin and comprises about 3500 m of Lower Cretaceous fluvial sediments that were deposited during the initiation of rifting between Antarctica and Australia (Megallaa 1993). Some estimates, not yet tested by drilling, suggest that the Strzelecki Group may locally incorporate as much as 6000 m (Dudley 1959) or 9000 m (Willcox et al. 1992) of sedimentary rocks. Deposition of the Strzelecki Group occurred between 140 and 98 Ma with sediments derived from cratonic highlands to the north (Griffiths 1971). Sedimentary rocks of the lowermost Strzelecki Group are exposed in several small areas on the Mornington Peninsula and Phillip Island (Figure 1) and in the Tyers district of north Gippsland (Figure 2). Victorian Mesozoic rocks were first assigned to the 'Oolitic' (McCoy 1860) or Jurassic because the fossil floras were considered similar to those known from the Yorkshire Oolite and the Rajmahal Hills Formation (then thought to be Liassic) of India. Stirling (1901), by contrast, argued that the fossils indicated a Triassic-Jurassic age based on identifications made by R. Etheridge Jr. A Jurassic age remained widely accepted until Dettmann (1963) established a detailed palynostratigraphic zonation of the Victorian Mesozoic sediments. Correlation with sequences from other basins and with biozones based on other fossil groups constrained the age to the Early Cretaceous (Neocomian to Albian). More recent palynostratigraphic studies (Helby et al. 1987; Morgan et al. 1995) have subdivided some of these zones, modified the criteria for the recognition of some zonal boundaries, and in some cases, they have adjusted the suggested correlation to the standard international stages. Additional uncertainties in correlation arise where workers have applied different absolute ages to various stage boundaries. In this study we use the ages proposed by Gradstein et al. (1994) (Figure 3). Deposition of the Strzelecki Group began during the Berriasian (basal Lower Foraminisporis wonthaggiensis Zone) and terminated in the Albian (Phimopollenites pannosus Zone) according to published spore-pollen data (Dettmann & Douglas 1988; Morgan et al. 1995) (Figure 3). However, the youngest exposed sediments of the Strzelecki Group are probably of Aptian age (Douglas 1969). Various stratigraphic schemes have been used to describe and subdivide the Lower Cretaceous Gippsland Basin sediments (Figure 3). Selwyn (1856) first referred to the sequence using the name 'Cape Paterson beds' but this term has not been widely employed. Stirling (1899) promoted the sequence to group status renaming it the Korumburra Group.
Early Cretaceous (Neocomian) flora and fauna of the Lower Strzelecki Group, Gippsland Basin, Victoria
Fossil assemblages are described from the Tyers River Subgroup (late Berriasian to Hauterivian), ... more Fossil assemblages are described from the Tyers River Subgroup (late Berriasian to Hauterivian), Gippsland Basin, Victoria. The assemblages include plant macrofossils referable to 33 form-species including five new species (Isoetites abundans Tosolini & McLoughlin, Coniopteris victoriensis Nagalingum & McLoughlin, Otozamites douglasii Drinnan, Brachyphyllum tyersensis Tosolini & Nagalingum, Otwayia hermata Tosolini & McLoughlin) and three new combinations [Medwellia lacerata (Douglas) Nagalingum & ...
Revision of an Early Cretaceous macroflora from the Maryborough Formation, Maryborough Basin, Queensland, Australia
Memoirs of the Queensland museum, 2000
Abstract An Early Cretaceous (Aptian or earliest Albian) impression flora is described from the u... more Abstract An Early Cretaceous (Aptian or earliest Albian) impression flora is described from the upper part of the Maryborough Formation in the Maryborough Basin, southern Queensland. The flora is preserved in marine sediments hosting an abundant invertebrate fauna dominated by bivalve molluscs. The flora incorporates single species attributable to the Polypodiophyta, Pentoxylales and Bennettitales. Two cuneate leaves have affinities either with the Ginkgoales or seed-ferns. Four species of conifer foliage are represented ...
068 The palynology and megaspores of Cretaceous (Aptian) high latitude, vertebrate-bearing fluvial sediments from the Gippsland Basin, south-eastern Australia
The Early Cretaceous (Barremian-Aptian) flora of the Binns Rd Quarry, Otway Ranges, Victoria
Victoria is endowed with the most continuous succession of Early Cretaceous floras of any part of... more Victoria is endowed with the most continuous succession of Early Cretaceous floras of any part of Australia, these Cretaceous floras are significant for several reasons. They are useful for biostratigraphic subdivision of the mainly non-marine sequence, the fossilised plant remains contributed to the coal deposits once mined near Wonthaggi in Gippsland, and the fossils help us to understand the nature of ancient high latitude forests for which there are no modern analogues. The partially degraded plant remains probably also contributed to the oil and gas reserves now exploited in the Gippsland and Otway Basins. The fossil assemblages are also significant in shO\ving the decline of several previously widespread and abundant gymnosperm groups from the Australian biota (Bennettitales, Pentoxylales, cheirolepidacean conifers, ginkgophytes; and sphenophytes) and the first appearances of some new groups, most notably the flowering plants. This article illustrates some of the fossils recen...
Early Cretaceous polar biotas of Victoria, southeastern Australia—an overview of research to date
Alcheringa: An Australasian Journal of Palaeontology
Palaeoecology: North–South recovery divide
Nature Ecology & Evolution, 2017
Early angiosperm diversification in the Albian of southeast Australia: implications for flowering plant radiation across eastern Gondwana
Review of Palaeobotany and Palynology, 2016
Evidence for Insect and Annelid Activity Across the Triassic-Jurassic Transition of East Greenland
PALAIOS, 2015
Late Cretaceous (Cenomanian–Turonian) macroflora from the Chatham Islands, New Zealand: Bryophytes, lycophytes and pteridophytes
Gondwana Research, 2014
Cheirolepidiacean foliage and pollen from Cretaceous high-latitudes of southeastern Australia
Gondwana Research, 2013
Cheirolepidiacean foliage and pollen from Cretaceous high-latitudes of southeastern Australia
Gondwana Research, 2013
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Papers by Anne-Marie Tosolini