1 Calories Burned For SparkPeople 28 Day Bootcamp (Boot Camp) DVD: 12-Minute Cardio Burst Workout. 2  Calories Burned For SparkPeople 28 Day Bootcamp (Boot Camp) DVD: 12-Minute Short Cardio Sculpt Workout.
Anther occurred when the Cretaceous period became the Tertiary about 65 million years ago, when 75 percent of species disappeared. This article is about the first mass extinction at the end of the Ordovician geological period 440 million years ago, when about 86 percent of species were killed.
Cretaceous-Tertiary mass extinction 65 million years ago ; Mass extinction theories. Asteroid impacts, climate change, volcanoes - there have been many theories about the causes of mass extinctions. In some cases, such as the Cretaceous mass extinction event, more than one such factor was involved in the global catastrophe. 1  Catastrophic methane release. 2  Flood basalt eruptions. 3  Climate change. 4  Impact events.