Read this essay to learn about the theories on the origin of angiosperms. Theories on the Origin of Angiosperms Essay Contents: Essay on the Isoetes-Monocotyledon Theory Essay on the Conifer-Amentiferae Theory Essay on the Gnetales-Angiosperm Theory Essay on the Bennettitalean Theory Essay on the Caytonialean Theory Essay on the Pteridosperm Theory Essay on the Pentoxylales […]