Two new fossil woods of the morphogenus Ginkgoxylon SAPORTA emend. SUSS from Tertiary layers of the Isle of Lesbos, Greece, with a survey of the fossils with ginkgoalean wood structure

摘要

The history of the morphogenus Ginkgoxylon SAPORTA will be diseussed and its diagnosis changed. Two Lower Miocene Ginkgoxyla from petrified forest of Lesbos, Greece, are described as Ginkgoxylon lesboense sp. nova and G. diversicellulatum sp. nova. The fossils with ginkgoalean wood structure are summarised in a survey. In addition, the paper discusses the occurrence of oblique rays and the causes of its origin.