How Soil Is Formed - Soil: Reflections on the Basis of our Existence - page 35

Ancient recipe for success. During the dinosaur era, gymnosperms such as gingko, cone palms
and, later, conifers dominated the flora. Cone palms succeeded by joining forces with cyanobac-
teria capable of capturing nitrogen from the air. Such symbiosis is today found in some lichens
but is unusual among plants. One example is the Gunnera family (photo), which is among our
oldest angiospermous (flowering) plants and which existed at the time of the dinosaurs. Other
groups, including legumes and alders, went on to evolve collaborative strategies with different
types of nitrogen-capturing bacteria