Answer:
The Microscope
Explanation:
Before the 1600s, every living thing was a part of a two kingdom classification system derivative of binomial nomenclature. This was proposed by Linnaeus, a Swedish Naturalist, who split all living things into either the animalia or plantae kingdom. After the invention of the microscope however, a new detailed classification system was put in order to accommodate for microscopic life. This new system recognizes the existence of 6 kingdoms: eubacteria, archaebacteria, prostista, fungi, plantae, and animalia.