Twenty-seven previously unknown species of spiders, centipedes, scorpion-like creatures and other animals have been discovered in the dark, damp caves beneath two national parks in the Sierra Nevada, biologists say.
"Not only are these animals new to science, but they're adapted to very specific environments — some of them, to a single room in one cave," said Joel Despain, a cave specialist who helped explore 30 of the 238 known caves in Sequoia and Kings Canyon National Parks.
The discoveries included a relative of the pill bug so translucent that its internal organs are visible, particularly its long, bright yellow liver. There was also a daddy long legs with jaws bigger than its body, and a tiny fluorescent orange spider.
"Many people will be looking at these trying to find where they fit in the tree of life," said Darrell Ubick, a cave biologist with the San Francisco-based California Academy of Sciences.
While it is extremely rare to find new mammal or bird species on the surface, caves still hold an abundance of secrets. Like the deep sea, they are often difficult to reach and seldom explored.
Discovering so many species was thrilling, said Jean Krejca, a consulting biologist with Austin, Texas-based Zara Environmental who helped lead the three-year exploration. The findings were released Tuesday.
"You get the feeling you're Lewis and Clark, charting undiscovered territory," she said. "Caves are one of the last frontiers."
Park officials plan to adopt measures to protect the caves, Despain said. Most of them are not accessible to the public, and can be visited only by researchers or experienced explorers with permits.
The species have yet to be named, described scientifically and placed in the continuum of known living organisms.
"We don't know how long they live, what kind of habitat they prefer, how many offspring they have, or how sensitive they are to human disturbance," Krejca said. "There's still so much to learn."