Iran's past vegetation in the Mesozoic Era

To understand the current distribution of plants, pay attention to the past status and development trends is inevitable. Iran has diverse geological sequences consisting of a great assemblage of diverse fossils, i.e. vertebrates, invertebrates, and plants. It takes living organisms millions of years to become fossils. In addition, suitable conditions for fossilization like burial in sediments and not exposed to weathering as well as other factors should be provided, so that a living organism becomes a fossil. Therefore, fossils are nonrenewable resources and need be studied and preserved as natural treasures.