His focus is on understanding the causes of mass extinctions and the processes that control subsequent recovery of biodiversity and global ecosystems. Jon’s research primarily spans two timescales: 1) that of catastrophic extinction events and their immediate aftermaths (up to a few million years) and 2) the timescale of geological periods and eras (tens to hundreds of millions of years). In addition to his research, he teaches undergraduate courses in historical geology and invertebrate paleobiology, as well as graduate courses in carbonate sedimentology and geobiology.