Microfossil: Fossil remnant of a microscopic organism or microscopic part of a larger organism such as pollen from a flowering plant or small teeth from a fish. Microfossils of bacteria provide evidence of the earliest life on earth.

Zooplankton: Tiny, floating aquatic animals that form an important part of food chains in freshwater and ocean ecosystems. Zooplankton typically eat phytoplankton, floating aquatic plants. Examples of zooplankton include water "fleas" (Daphnia), copepods, and "krill," a group of soft-bodied marine arthropods.