Question

what do scientists call an event when many species die out at once?
erosion
mass extinction
volcanic eruption
fossil formation

Explanation:

• Erosion is the process of wearing away rocks and soil.
• Mass extinction is defined as an event where a large number of species die out simultaneously.
• Volcanic eruption is the release of magma, ash, etc. from a volcano.
• Fossil formation is the process of organisms turning into fossils.

Answer:

Mass extinction