Macrofossils are easier to find. Fossilized plants and animals, and their parts and traces are all macrofossils. Microfossils are tiny, but recognizable, bits of plant or animal matter. They occur in thousands of different forms, but the most common are pollen grains, spores, reproductive structures of fungi, and numerous walls of microscopic algae. These are all invisible to the unaided eye, but easily recognized in a microscope.
Microfossils are informative and abundant, occurring in many kinds of sediment.
This is easy to understand if you think about how many tiny grains of pollen blow around every year in British Columbia. Plant fossils, especially pollen and spores, provide paleobotanists with one of the most powerful tools of understanding the history of ecosystems and the processes that shape them. Any change of the landscape immediately results in a change in the types of plants that grow there. Plant fossils also document changes in climate. Palms, for example, tend to live in warm regions, spruce trees thrive where the weather grows cold, and ferns require a great deal of moisture.