image: Cuticle layers of upper (left) and lower (right) leaflet surface of a seed-fern frond from the Permian of Jordan showing the epidermal cell pattern with the characteristic distribution of the plant's stomata, the pores facilitating gas exchange. This material relates to a paper that appeared in the 21 Dec., issue of Science, published by AAAS. The paper, by P. Blomenkemper at University of Münster in Münster, Germany and colleagues was titled, "A hidden cradle of plant evolution in Permian tropical lowlands." view more
Credit: [Credit: Palaeobotany Research Group Münster]