MAIN TYPES OF FOSSILS
The beginning [fossil] collector is usually amazed by the many different plants and animals that have left some trace of their existence. In order to understand these different types of prehistoric life, it is necessary to know something about the organisms that are living today.
This handbook discusses the more important groups of plants and animals which have left some sort of paleontological record, and each major group begins with a discussion of the more simple organisms and continues through the more advanced forms. Because scientific workers do not always agree on exactly the same classification, the [system] adopted in this handbook contains the latest ideas of several workers. It is simple enough to understand, yet complete enough to help one know and classify his fossils. It should be noted that this classification may differ in some respects from that of certain older paleontological publications. Therefore, it has seemed advisable to list other names for some of the groups that are discussed.
In some instances, the brief descriptions and illustrations of each group will enable the collector to make a preliminary identification of his fossils. For more detailed information about each group, the reader should refer to “Books About Fossils” (pp. [108]-110).
This part of the handbook begins with a brief summary of the major groups of the plant kingdom, followed by a discussion of the characteristics and relative paleontological importance of the various invertebrate animals. Emphasis is placed on the invertebrates because this type of [fossil] is most commonly collected by the amateur. Finally, there is a general review of the vertebrates.