See these annular structures?

They are 492 million years old and come from Wisconsin. Here are some more.

Was there a severe shortage of beer coasters in Cambrian Wisconsin?

We've seen a lot of interesting fossils around the blog lately (see here, for instance, for some strange fossils that are four times as old as these rings). But as you can see, I have another set for you. At 492 million years old, they predate most forms of complex life, which makes their appearance and the mystery of what made them all the more puzzling. They can also earn you $500 if you manage to come up with the "the best natural explanation" (i.e., no aliens or foil helmets allowed) for their formation. The contest in question is brought to you by some nice folks at the University of California Riverside. See?

Hoooookay then. There is a second video that explains the problem and the fossils in more detail. In addition to being informative and a great effort at citizen science and public outreach, it also appears to be some sort of bizarre student recruitment tool, with entertainingly non sequitur publicity spots sprinkled throughout, like those ads for universities that run on TV during college football bowl games. Whatever the case, the result is still interesting and charmingly earnest.

Thank god that I now know the home of the world's largest paper cup. : ) In any case, if you'd like to find out more about and potentially enter this contest which runs through 4 p.m. Pacific Time on March 11, check out their website here and here.

https://www.nature.com/srep/2015/150216/srep08495/full/srep08495.html?WT.ec_id=SREP-631-20150217