" A surge of volcanic activity around 65 million years ago could have triggered a mass extinction by pumping sulphur and chlorine into the atmosphere."
Dinosaur killer found in volcanic bubbles. New Scientist. 01 April 2008. Available from: http://www.newscientist.com/channel/life/mg19726494.700-dinosaur-killer-found-in-volcanic-bubbles.html.

What where the sulfur loving bacteria doing at this time?
What impact did this increase of sulfur have on the sulfur chemolithotrophic bacteria?