<em>Ecpagloxylon mathiesenii</em> gen. nov. et sp. nov., a Jurassic wood from Greenland with several primitive angiosperm features

International audienceFossil wood specimens from the late Early-early Middle Jurassic of Jameson Land, Eastern Greenland, have several unexpected features: tracheids of irregular size and shape, thinly pitted ray cell walls, heterogeneous rays, partially scalariform radial pitting, both areolate and simple pits, and pitted elements associated with rays. These characters diverge markedly from those typical of Jurassic wood, which usually conform to those of modern conifers. Although this combination of features is not encountered in any extant angiosperm, each has been documented in one or several extant homoxylous angiosperms, particularly Amborella, Trochodendron, and Tetracentron. As these wood specimens are not found in connection with any reproductive part, it is impossible to confidently assign them to the angiosperms. If a Jurassic angiosperm did exist, however, it might well have had a similar wood. This material is an early bench-mark in the evolution that led from homoxylous conifer-like wood to that of the angiosperms. Its particular biogeography (Arctic) could renew the discussion about the area of origin of the angiosperm

New fossil woods from the early Cenozoic volcano-sedimentary rocks in the Fildes Peninsula, King George Island, and implications for the trans-Antarctic Peninsula Eocene climatic gradient

Ten embedded fossil logs sampled in situ from the middle Eocene volcano-sedimentary rocks close to Suffield Point in the Fildes Peninsula, King George Island,Antarctica, are assigned to Protopodocarpoxylon araucarioides Schultze-Motel ex Vogellehner, Phyllocladoxylon antarcticum Gothan, Agathoxylon antarcticum (Poole &amp; Cantrill) Pujana et al., A. pseudoparenchymatosum (Gothan) Pujana et al. andan unidentified angiosperm wood. Differences in the taxonomic representation and growth-ring characters of the Eocene woods on King George Island and coeval assemblages from Seymour Island, on the western and eastern sides of the Antarctic Peninsula respectively, are interpreted to result from environmental and climatic gradients across the Peninsula Orogen during the early Palaeogene. In particular, a precipitation gradient inferred across the Peninsula at that time might have been induced by a rain-shadow effect.This research is a part of the project ‘Long-Term Ecological Researches on King George Island to Predict Ecosystem Responses to Climate Change (PE15020)’ funded by the Korea Polar Research Institute, KOREA. Also funded by National Science Foundation (project #1636625)</p