Unique to the Mazon Creek Formation in Illinois, it became its state fossil in 1989. Soft-bodied and relatively small (a living specimen would fit in a human hand), with its stalked eyes and long ...

“The fossil’s very spiny legs are reminiscent ... Rainforest Collapse,’ a time shortly after the age of Mazon Creek when the coal forests began to fragment and die off.

A fossil of the creature was originally unearthed from the Mazon Creek deposit in northeastern Illinois by Bob Masek, a ...