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.
But the rate of extinction is far from constant. At least a handful of times in the last 500 million years, 50 to more than 90 percent of all species on Earth have disappeared in a geological blink of the eye. Though these mass extinctions are deadly events, they open up the planet for new life-forms to emerge.Dinosaurs appeared after one of the biggest mass extinction events on Earth, the Permian-Triassic extinction about 250 million years ago.ut the rate of extinction is far from constant. At least a handful of times in the last 500 million years, 50 to more than 90 percent of all species on Earth have disappeared in a geological blink of the eye. Though these mass extinctions are deadly events, they open up the planet for new life-forms to emerge.