UC Riverside is offering a $500 cash reward for the best explanation of fossil rings discovered in 492 million year old rocks from Wisconsin. They are a bunch of paleontologists that want you to stretch your mind and come up with creative explanations for a real scientific problem. So, think logically, what caused these intriguing ring-line structures on the seabed so many years ago? Some of you may even have visited the quarry (in southwestern Wisconsin) where these fossils were found. The contest runs through 4 P.M. Pacific Time on March 11. You can find the rules here. Get your entries in!