Living Fossils

Abstract

Fossil land plants, including angiosperms, particularly of the late Mesozoic and early Tertiary, have evolved conservatively. Many common American trees are practically unchanged and might be termed ''living fossils. ''Animal life, on the contrary, has altered radically. The earliest plants were probably small thallus forms. Vascular plants occur in the Devonian, and seed plants in the late Carboniferous or Permian. Plant fossils are related to the present spp. of the same areas, since plants are incapable of locomotion. Thus, fossil distribution is a good geological indicator.