Swimming sperm in an extinct Gondwanan plant: Palaeobotany

The now-extinct plant Glossopteris that dominated the Southern Hemisphere (Gondwana) during the Permian period serves as early evidence of continental drift 1 , 2 , and may be ancestral to the group of seed plants known as angiosperms 3 . Here we describe a 250-million-year-old fossil from Homevale in Queensland, Australia, of anatomically preserved pollen tubes and swimming male gametes from Glossopteris. The discovery of this simple reproductive system in Glossopteris has implications for its phylogenetic relationships with extant groups of seed plants (conifers and flowering plants, for example) and for the evolution of pollination biology in general.