Book excerpt: The Late Pennsylvanian was a time of ice ages and associated climate dynamics. A major reduction in Gondwana ice-volume was followed by a prolonged period of relative global warmth, culminating in the last great ice age of the late Paleozoic. It also was a major turning point in the evolution of life on land, when the coal forests of the Middle Pennsylvanian gave way to new kinds of Late Pennsylvanian wetland vegetation, and new kinds of animals appeared. Changes in the terrestrial biota began during the Middle Pennsylvanian, accelerating and proceeding in a spatially complex manner throughout the Late Pennsylvanian. The Late Pennsylvanian is thus a laboratory for studying environmental changes in a glacial world, and for assessing coeval biotic changes, in part to establish the possible links between the two. No book has been dedicated to this time interval, so this volume fills a gap in our understanding of a dynamic Late Pennsylvanian world that is much like the late Cenozoic world.