| 1. |
- CARPENTER, RAYMOND, et al.
(författare)
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EARLY EVIDENCE OF XEROMORPHY IN ANGIOSPERMS: STOMATAL ENCRYPTION IN A NEW EOCENE SPECIES OF BANKSIA (PROTEACEAE) FROM WESTERN AUSTRALIA
- 2014
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Ingår i: American Journal of Botany. - : Wiley. - 0002-9122 .- 1537-2197. ; 101:9, s. 1486-1497
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Tidskriftsartikel (refereegranskat)abstract
- Premise of the study: Globally, the origins of xeromorphic traits in modern angiosperm lineages are obscure but are thought to be linked to the early Neogene onset of seasonally arid climates. Stomatal encryption is a xeromorphic trait that is prominent in Banksia , an archetypal genus centered in one of the world’s most diverse ecosystems, the ancient infertile landscape of Mediterranean-climate southwestern Australia.Methods: We describe Banksia paleocrypta , a sclerophyllous species with encrypted stomata from silcretes of the Walebing and Kojonup regions of southwestern Australia dated as Late Eocene.Key results: Banksia paleocrypta shows evidence of foliar xeromorphy ~20 Ma before the widely accepted timing for the onset of aridity in Australia. Species of Banksia subgenus Banksia with very similar leaves are extant in southwestern Australia. The conditions required for silcrete formation infer fl uctuating water tables and climatic seasonality in southwestern Australia in the Eocene, and seasonality is supported by the paucity of angiosperm closed-forest elements among the fossil taxa preserved with B. paleocrypta. However, climates in the region during the Eocene are unlikely to have experienced seasons as hot and dry as present-day summers.Conclusions: The presence of B. paleocrypta within the center of diversity of subgenus Banksia in edaphically ancient southwestern Australia is consistent with the continuous presence of this lineage in the region for ≥ 40 Ma, a testament to the success of increasingly xeromorphic traits in Banksia over an interval in which numerous other lineages became extinct.
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| 2. |
- Falster, Daniel, et al.
(författare)
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AusTraits, a curated plant trait database for the Australian flora
- 2021
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Ingår i: Scientific Data. - : Nature Portfolio. - 2052-4463. ; 8:1
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Tidskriftsartikel (refereegranskat)abstract
- We introduce the AusTraits database - a compilation of values of plant traits for taxa in the Australian flora (hereafter AusTraits). AusTraits synthesises data on 448 traits across 28,640 taxa from field campaigns, published literature, taxonomic monographs, and individual taxon descriptions. Traits vary in scope from physiological measures of performance (e.g. photosynthetic gas exchange, water-use efficiency) to morphological attributes (e.g. leaf area, seed mass, plant height) which link to aspects of ecological variation. AusTraits contains curated and harmonised individual- and species-level measurements coupled to, where available, contextual information on site properties and experimental conditions. This article provides information on version 3.0.2 of AusTraits which contains data for 997,808 trait-by-taxon combinations. We envision AusTraits as an ongoing collaborative initiative for easily archiving and sharing trait data, which also provides a template for other national or regional initiatives globally to fill persistent gaps in trait knowledge.
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| 3. |
- McLoughlin, Stephen, 1964-, et al.
(författare)
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Seed ferns survived the end-Cretaceous mass extinction in Tasmania.
- 2008
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Ingår i: American Journal of Botany. - : Wiley. - 0002-9122 .- 1537-2197. ; 95:4, s. 465-71
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Tidskriftsartikel (refereegranskat)abstract
- Seed ferns, dominant elements of the vegetation in many parts of the world from the Triassic to Cretaceous, were considered to have disappeared at the end of the Cretaceous together with several other groups that had occupied key positions in terrestrial and marine ecosystems such as dinosaurs, plesiosaurs, and ammonoids. Seed-fern demise is generally correlated with competition from diversifying flowering plants through the Cretaceous and the global environmental crisis related to the Chicxulub impact event in the paleotropics at the end of the period. New fossils from Tasmania show that one seed-fern lineage survived into the Cenozoic by at least 13 million years. These fossils are described here as a new species, Komlopteris cenozoicus. Komlopteris is a genus of seed ferns attributed to Corystospermaceae and until now was not known from sediments younger than the Early Cretaceous. Discovery of this "Lazarus taxon," together with the presence of a range of other relictual fossil and extant organisms in Tasmania, other southern Gondwanan provinces, and some regions of northern North America and Asia, underscores high-latitude regions as biodiversity refugia during global environmental crises and highlights their importance as sources of postextinction radiations.
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| 4. |
- Peyrot, Daniel, et al.
(författare)
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The greening of Western Australian landscapes: the Phanerozoic plant record
- 2019
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Ingår i: Journal of the Royal Society of Western Australia. - Perth : Royal Society of Western Australia. - 0035-922X. ; 102, s. 52-82
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Tidskriftsartikel (refereegranskat)abstract
- Western Australian terrestrial floras first appeared in the Middle Ordovician (c. 460 Ma) and developed Gondwanan affinities in the Permian. During the Mesozoic, these floras transitioned to acquire a distinctly austral character in response to further changes in the continent’s palaeolatitude and its increasing isolation from other parts of Gondwana. This synthesis of landscape evolution is based on palaeobotanical and palynological evidence mostly assembled during the last 60 years. The composition of the plant communities and the structure of vegetation changed markedly through the Phanerozoic. The Middle Ordovician –Middle Devonian was characterised by diminutive vegetation in low-diversity communities. An increase in plant size is inferred from the Devonian record, particularly from that of the Late Devonian when a significant part of the flora was arborescent. Changes in plant growth-forms accompanied a major expansion of vegetation cover to episodically or permanently flooded lowland settings and, from the latest Mississippian onwards, to dry hinterland environments. Wetter conditions during the Permian yielded waterlogged environments with complex swamp communities dominated by Glossopteris. In response to the Permian–Triassic extinction event, a transitional vegetation characterised by herbaceous lycopsids became dominant but was largely replaced by the Middle Triassic with seed ferns and shrubs or trees attributed to Dicroidium. Another floristic turnover at the Triassic–Jurassic boundary introduced precursors of Australia’s modern vegetation and other southern hemisphere regions. Most importantly, flowering plants gained ascendancy during the Late Cretaceous. Characteristics of the state’s modern vegetation, such as sclerophylly and xeromorphy, arose during the Late Cretaceous and Paleogene. The vegetation progressively developed its present-day structure and composition in response to the increasing aridity during the Neogene–Quaternary.
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