Throughout the past 250 years of scientific classification, biologists have discovered and described as many as 1.2 million separate plant and animal species. Yet they're still only scratching the surface of what odd organisms are out there, wandering our world. In fact, biodiversity specialists say a shocking number of species have not been subject to scientific study. Though approximations differ, one commonly cited paper posits that around 86 percent of the planet's plants and animals have yet to be formally classified, including about 91 percent of ocean species.