Mysterious Moss Pattern Baffles Scientists.

This mysterious circular pattern on moss-covered logs is baffling scientists:

Last winter, researchers in the Great Smoky Mountains National Park discovered the symmetrical bull’s-eye pattern on patches of liverwort (a close relative of moss) growing on pine trees that had died and fallen on the ground.

At this point, biologists aren’t sure what causes the circles. Some have suggested snails, while others have speculated millipedes.

"Immediately, we thought of snails," said Keith Langdon, chief biologist with the Smokies. "But snails graze in a zigzag pattern. We can’t find records of anything like this in the park. It appears to be a rare phenomenon."

Link – via Fortean Times