Habit and Ecology of the Petriellales, an Unusual Group of Seed Plants from the Triassic of Gondwana
2014 (English)In: International journal of plant sciences, ISSN 1058-5893, E-ISSN 1537-5315, Vol. 175, no 9, 1062-1075 p.Article in journal (Refereed) Published
Premise of research. Well-preserved Triassic plant fossils from Antarctica yield insights into the physiology of plant growth under the seasonal light regimes of warm polar forests, a type of ecosystem without any modern analogue. Among the many well-known Triassic plants from Antarctica is the enigmatic Petriellaea triangulata, a dispersed seedpod structure that is considered a possible homologue of the angiosperm carpel. However, the morphology and physiology of the plants that produced these seedpods have so far remained largely elusive.
Methodology. Here, we describe petriellalean stems and leaves in compression and anatomical preservation that enable a detailed interpretation of the physiology and ecology of these plants.
Pivotal results. Our results indicate that the Petriellales were diminutive, evergreen, shade-adapted perennial shrubs that colonized the understory of the deciduous forest biome of polar Gondwana. This life form is very unlike that of any other known seed-plant group of that time. By contrast, it fits remarkably well into the “dark and disturbed” niche that some authors considered to have sheltered the rise of the flowering plants some 100 Myr later.
Conclusions. The hitherto enigmatic Petriellales are now among the most comprehensively reconstructed groups of extinct seed plants and emerge as promising candidates for elucidating the mysterious origin of the angiosperms.
Place, publisher, year, edition, pages
University of Chicago Press, 2014. Vol. 175, no 9, 1062-1075 p.
Petriellales, gymnosperms, Triassic, paleoecology, polar forests, Antarctica
Other Earth and Related Environmental Sciences
Research subject The changing Earth
IdentifiersURN: urn:nbn:se:nrm:diva-974DOI: DOI:10.1086/678087OAI: oai:DiVA.org:nrm-974DiVA: diva2:769637
FunderSwedish Research Council, 2010-3931