Dicroidium diversity in the Upper Triassic of north Victoria Land, East Antarctica

摘要: Abstract We describe an assemblage of well-preserved, cuticle-bearing plant compressions collected from a single bed in the Upper Triassic Timber Peak, East Antarctica. The flora is dominated by seed fern Dicroidium, morphogenus that widespread and usually dominant Middle to Late assemblages throughout Gondwana. Despite its common occurrence, systematic classification Dicroidium individual species remains problematic. This study demonstrates combination macromorphological cuticular features enables suitable discrimination species. present remarkably diverse D. elongatum with subordinate proportions odontopteroides, crassinervis, new provisionally named sp. A. In addition, dubium, spinifolium, coriaceum occur sporadically. reinstitute spinifolium propose emended diagnosis. Other taxa include putative bryophyte remains, Lepidopteris langlohensis, Heidiphyllum elongatum. Another collection fossils second plant-bearing horizon at Peak consists fragmentary Cladophlebis H. Epidermal fronds suggest this flourished under favourable climatic conditions, although it was situated latitudes about 70° S must have experienced long annual periods darkness during austral winter. cuticles studied point short leaf lifespan very high photosynthetic performance fronds. phenology has facilitated plants colonize polar greenhouse world so successfully.