by Jackuul » July 19th, 2009, 8:00 pm
That mostly comes from writing content for a website, as I am working on a long-delayed article about the Permian-Triassic extinction event. The Permian is when synapsids ruled the world the first time, the extinction event wiped them out with exception of three known groups, and lead to the dinosaurs, a reptile, dominating the world.
Synapsids rule the world again, since well... 65 million years ago the reptiles took a hit and only the birds were left (however most everything else survived surprisingly - it is a drop in the bucket compared to the Permian-Triassic event). Mammals, and their ancestors, go back some 320 million years, and predated the reptiles in being a dominating force on the planet (as reptile-like mammaliforms).
Reason I am writing this paper is the recent trend of extinctions is actually outpacing the Permian-Triassic event (which wiped out 90% of all species across the board on the whole planet - including the trilobites) in under a million years. We may be looking at 50% in less than 50.