New type of joint found in nature: a screw!

Yep. A type of weevil has a hip joint unlike the two normal types of joints found in animals, the hinge and the ball-and-socket. The weevil uses a screw thread that goes through a nut. There's a tiny hole in the middle of the screw to allow blood to circulate.
COMMENT: Biologists have wondered why nature never hit on the wheel in all these billions of years of experimentation. As far as we know, that mystery is unsolved, but this little bit of news reminds us just how many variations can pop out of a long, messy process like evolution. (As a Christian, I believe this process did have a foreordained end result - a species intelligent enough to become spiritually aware - but it sure was a long, strange trip.)