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.
The big five mass extinctions. Biologists suspect weâre living through the sixth major mass extinction. Earth has witnessed five, when more than 75% of species disappeared. Palaeontologists spot them when species go missing from the global fossil record, including the iconic specimens shown here.