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INTRODUCTION

Any classification can, at best, only express our present level of understanding of genetic relationships.  Because there is room for interpretation, there may be several classification schemes for a given group.  In the past, most of us were taught that there are two kingdoms of living things: Plants and Animals.  Of late it has been recognized that there are greater differences between these groups than thought and one recent scheme of classification recognizes six kingdoms:

1. Archaeobacteria (often lumped in the Kingdom Procaryota or  Monera along with the Eubacteria) are primitive procaryotes (cells without well defined organelles); includes sulphur and methane reducing bacteria and bacteria capable of living in extreme environments such as hot springs or hypersaline environments. Commonly anaerobic.

2. Eubacteria  (were also lumped into the Kingdom Procaryota or Monera, along with the Archaeobacteria) are more advanced procaryotes. One Phylum, the Cyanobacteria ( also called cyanophytes or Blue-Green algae) are the earliest fossils

3. Protista (also called Eucaryota)-single or multiple-celled eukaryotic organisms with well defined organelles. This most diverse kingdom includes most algae. The next three kingdoms all arose from the protists.

4. Plantae. Multicellular eukaryotes that photosynthesize using chloroplasts

5. Fungi. Single or multicellular eukaryotes that break down decaying organic matter. Includes molds, slime molds, yeasts fungi and mushrooms.

6. Animalia. Multicellular heterotrophic eukaryotes that ingest other organisms for food.

The following pages are by no means comprehensive but selectively review fossil groups which are commonly used for zonation by geologists.