New spider family identified in Oregon SCIENCE

This trogloraptoran belongs to a new family of spiders discovered in the wilds of southern Oregon. This trogloraptoran belongs to a new family of spiders discovered in the wilds of southern Oregon. Photo: Joel Ledford, Calif Academy Of The Sciences Photo: Joel Ledford, Calif Academy Of The Sciences Image 1 of / 1 Caption Close New spider family identified in Oregon 1 / 1 Back to Gallery

Cave hunting biologists from San Francisco, working with a team of speleologists in the wilds of southern Oregon, have discovered a new family of spiders never before known to science.

The spindly, six-eyed members of the worldwide arachnid tribe appear to have evolved their fearsome elongated claws over hundreds of millions of years, but how they attack their prey and how and what they eat are still unknown, the scientists say.

The newfound spider family is being named trogloraptor, meaning "cave robber," and the single species found near Grants Pass is named Trogloraptor marchingtoni for Neil Marchington, a Deschutes County deputy sheriff who is also an amateur biologist and local cave explorer who helped lead the team of scientists to caves where the spiders were found.

The science team was led by entomologist Charles Griswold of the California Academy of Sciences. He is an internationally noted specialist in all things arachnid - including spiders, scorpions, mites, ticks and the harvestmen known as daddy long-legs.

A report on the discovery by Griswold and his colleagues, graduate student Tracy Audisio of San Francisco State and postdoctoral researcher Joel Ledford of UC Davis, has been accepted for publication in ZooKeys, a peer-reviewed zoology journal.

Audisio said Wednesday that she and Marchington were part of a group, all members of the Western Cave Conservancy, that made the first discovery of the trogloraptor family.

The mystery spiders were brought back to Griswold's arachnid lab at the academy for detailed analysis. Now another team of what Griswold calls "citizen scientists" has brought in two more live adult trogloraptors and three juveniles that were discovered deep in the old-growth forest of the Jedediah Smith Redwoods State Park, near Crescent City.

"We tried to learn what they eat," Audisio said, "so we built a cold little cave for them and gave them crickets and flies and moths and even other spiders, but they didn't eat anything and after three weeks they all died, so we still don't know."

The adults are huge for any spider - about the size of a 50-cent piece - and they spin primitive webs with only a few strands, but hang beneath those webs from the cool, damp ceilings of the caves, Griswold said.

Primitive relatives of other arachnid families may yet be discovered in the same regions, he noted, because many unique evolutionary descendants of other widespread groups live there, including coast redwoods, mountain beavers, coastal-tailed frogs, and some pseudoscorpions whose evolutionary ancestors date back 380 million years.

To biologists of all disciplines, merely discovering a single new species of animal or plant can be a major accomplishment. And discovering a new genus - a group that may include many new species - is a triumph.

But discovering an entire new family that might include genus after genus and species after species is rare indeed.

"This is something completely new," said Griswold of the team's cave discovery. "It's a historic event."