August 10, 2011
The Earth has been undergoing what some scientists call the Sixth Extinction Event. Of the 10 million known species of life on the planet, 5 million of these are believed by many to be on course to become extinct within the next 100 years.
There is a debate as to whether the mass extinctions of wildlife documented by humans since 1500 AD represent a separate event from the ongoing extinctions over the past 12,000 years. These extinctions include several species of giant ground sloths, which were as as large as today’s elephants, the American lion and the many species of mammoths which ranged from Africa, Europe, Asia and the Americas, as far south as Nicaragua and Honduras.
A lot has been discussed about the Cretacious-Tertiary (or “K-T”) Extinction Event Event 65.5 million years ago, during which it is thought that 75% of all species on Earth became extinct, most famously the dinosaurs.
This clip is about the Permian Mass Extinction, which occurred 250 million years ago and wiped out 95% of the existing species, ushering in the age of the dinosaurs.
In paleontology, the “half-forgotten” animals which dominated the Earth during that era are called therapsids. They are considered to be the forerunners of both the dinosaurs and the mammalians.