500 million-year-old fossil illuminates a bizarre evolutionary mystery - Inverse

The Cambrian brought a huge proliferation of species that emerged from the seas, including this ancient starfish relative. Only its arms, or ambulacra, were calcified, protecting its “food grooves.”

After four years of digging for fossils in a churchyard in York, Pennsylvania, amateur paleontologist Chris Haefner made an intriguing find. I knew it was worth keeping, he said. He posted his disc… [+6089 chars]

full article...