Read any estimate of the number of species present on Earth, and you'll notice two things: the numbers vary wildly, and they're always well above the number of species we actually know about. It's tempting to think we've exhausted the exploration of the Earth, that there's nothing new to see. But one area that we've barely scratched the surface of is the biological diversity that we're a part of.

There are several reasons for this. One is that some habitats, like the deep ocean, are both vast and hard to get to. Others, like caves and islands, isolate populations and generate species at a phenomenal rate. Finally, there's just a tendency to view, say, all ants as being roughly the same. That can allow species to hide in plain sight, with nobody taking the time to look for the details that distinguish them from their close relatives. DNA sequencing is also telling us that some populations that we see as identical haven't actually interbred in a very long time and may be separate species.

As researchers gradually look more closely, the result is a steady stream of new discoveries. We thought we'd share some with you. We set a few simple guidelines for inclusion. The first is that the species had to be discovered this year. The second is that it has to be still living—paleontologists find new species almost as often as biologists do. The final thing is that we had to be able to come up with a decent photo of it.

While those are some pretty spectacular finds, remember that lots of organisms didn't make the cut, and some of these represent just one of a set of new discoveries. Plus, the year's not over yet.