The world's vertebrates — a class of animals that includes mammals, birds, reptiles, amphibians, and fish — are going extinct at a rate 114 times faster than what is considered to be the norm. According to a new study published in the journal Science Advances, the number of animals that went extinct in the past century is equivalent to the number of animals that typically would go extinct within a period of 800-10,000 years. At this rate, scientists say, the Earth is headed toward a mass extinction of a size that hasn't been seen since dinosaurs were wiped off the planet 65 million years ago.