People have imagined some pretty strange creatures living on both real and fictional planets: for example, little green men from the Milky Way and tall, hairy Wookiees from a galaxy far, far away. But life here on Earth is sometimes just as fantastic. In May, a committee of taxonomists highlighted OUR PLANET'S BIODIVERSITY by announcing the top 10 new species discovered in 2010. The list includes a flatfish that hops along the bottom of the Gulf of Mexico with its fins, a spider that spins webs spanning rivers 80 feet wide, and a bacterium that feeds on the rusted hull of the R.M.S. Titanic.