What term describes the extinction of two interdependent species?

Co-extinction

Explanation:

Co-extinction - occurs as a result of extinction of interdependent species. When one interdependent species is lost its also leads to the extinction of the other species. Example is Two lice that lives on a bird. extinction of an interdependent species a lice will lead to extinction of the other lice.

Mass Extinction - is the loss of a population of organism over time. Its result in extinction of a particular organism from in a place over a period of time.