What are the theories that caused mass extinctions?

loss of habitat (change of habitat, turns too cold, too hot, too dry, too wet, ect)

loss of food (where we lose almost all plants and the in tire food chain collapses. along with us)

disease (self explanatory)

freezing (earth freezes over into another ice age)

flooding (after ice age effect the ice melts)

comets (the ash covers sun and kills plants. Same thing with loss of food except the ash can also possibly choke us)

super volcanoes (the ash covers sun and kills plants. Same thing with loss of food except the ash can also possibly choke us)

another animal claims the top of the food chain (mostly sci-fi)