The three-foot long, giant Palouse earthworm has only been seen a few times in the last century, for which many people are probably grateful.

But scary or not, the Palouse earthworm (Driloleirus americanus) is critically endangered, and both it and its ecosystem in portions of Idaho and Washington are in danger of being wiped out.

That’s why the Center for Biological Diversity and several partner groups have, for the second time in three years, filed a petition to protect the giant worm, through the Endangered Species List.

The groups filed their first petition back in August 2006. The U.S. Fish and Wildlife Service did not respond within the federally required 90-day and 12-month periods, so the groups filed a lawsuit in 2007. The FWS later rejected their petition, saying there wasn’t enough information about the species available to justify that it needed protection.

Of course, if a species is only seen four times in 110 years, it's hard to gain enough scientific information about it to say that it is officially endangered, why it is endangered, and what needs to be done to protect it.

Actually, many thought the Palouse earthworm was already extinct. University of Idaho graduate student Yaniria Sanchez-de Leon rediscovered the species in 2005 (the news was announced in 2006), and a few more possible samples were uncovered last year.

The worm, which reportedly emits a flowery fragrance when handled and spits when threatened , remains the largest worm in North America. At least for now.

Image: Giant Palouse earthworm by Yaniria Sanchez-de Leon/University of Idaho © 2005