Add Yahoo as a preferred source to see more of our stories on Google. I've heard it time and time again that 'the early bird gets the worm,' but I know I'm not the only one who feels less productive ...

Sign up for CNN’s Wonder Theory science newsletter. Explore the universe with news on fascinating discoveries, scientific advancements and more. Modern sloths hang ...

Giant ground sloths have often been portrayed as gentle giants of the ice age. Much of their anatomy, from their flat molars to their vat-like guts, seems consistent with a diet centered around the ...