Unless you've been living in a cave, you probably haven't run across this new species of poisonous, nearly blind pseudoscorpion.

The 0.5-inch-long (1.3-centimeter-long) species, Cryptogreagris steinmanni, was discovered recently in high-altitude caverns near Glenwood Springs, Colorado.

Pseudoscorpions are essentially scorpions that lack a stinging tail. However, the new species does have long, venom-tipped pincers that likely help it nab agile prey, such as springtails, in the gloom.

Most likely, the new pseudoscorpion lives only in Glenwood Caverns and Historic Fairy Caves, the study authors say.

"A lot of these caves are islands, almost like an isolated environment where invertebrates ... evolve into being adapted to underground life," said biospeleologist David Steinmann, a zoology department associate with the Denver Museum of Nature and Science. Steinmann collected the new species after it was discovered in 2000 by tour guide Micah Ball.

With its primitive eyes and pale color, the arachnid is perfectly suited to its dark, chilly existence and has probably been scurrying through the passages for millions of years, Steinmann said.

New Pseudoscorpion Elusive—Until Now

Little is known about C. steinmanni, but it's thought to be rare, relatively long-lived, and able to curl up into a defensive ball when threatened.

The animal went unnoticed for so long because it blends in well with the rocks—and because few people have been crawling around caves looking for tiny creatures.

Steinmann, an avid caver, has discovered more than a hundred new invertebrate species so far in Colorado caves, including at least seven in Glenwood Springs alone. (See cave pictures.)

"It's always fun to see what's out there."