Answer:a species on which other species in an ecosystem largely depend, such that if it were removed the ecosystem would change drastically.
Step-by-step explanation:
The American Beaver (Castor canadensis) is one example of a keystone species in North America. In any arrangement or community, the “keystone” is considered one of the most vital parts. In a marine ecosystem, or any type of ecosystem, a keystone species is an organism that helps hold the system together.