Abstract

Fossil wood is present within the Weller Coal Measures of late Early Permian age at Allan Hills, southern Victoria Land, Transantarctic Mountains. It is preserved within coals and fluvial sediments as permineralised upright stumps and drifted trunks, along with Glossopteris leaves and Vertebraria rootlets. These fossils represent forests of Glossopteris trees that grew in swamps on the floodplain of a large meandering river (or rivers) at latitudes of about 80°S. The presence of a glacially striated boulder and other indicators of glacial environments within the sediments suggests that ice was present on surrounding highlands. Growth rings in the fossil wood are wide and uniform, are formed of a large number of cells and do not show frost damage. They indicate that tree growth was rapid during warm growing seasons, but slowed gradually as conditions deteriorated. Evidence from plant fossils and sediments shows that the climate was seasonal, with warm summers and cold, possibly freezing winters.