New geological evidence suggests that massive volcanism caught Earth's climate in a peculiarly unstable state at the end of the Ordivician geological period, triggering rapid climate fluctuations that led to a mass extinction.
Fike holds a 443-million-year-old slab of Ordovician limestone from Anticosti Island in Quebec that is sprinkled with the fossilized remains of marine creatures killed during a cooling pulse.
The lopsided location of landmasses at the end of the Ordivician is also thought to have played a role in the instability that led to mass extinctions.