Crack bit of paleontological detective work detailed in a new Nature article about Anomalocaris, a three-foot-long shrimp-like creature widely believed to have dominated the seas of the Paleozoic era's Cambrian period by "hunting and eating hard-shelled prey such as trilobites." In a recent computer-assisted analysis of fossilized Anomalocaris mouth parts, Amherst College's Whitey Hagadorn determined that the "Tyranosaurus rex of the Cambrian" lacked the chomping power to match its reputation. "Everyone shows it grabbing trilobites and munching them. Like a cookie monster," Hagadorn says. "Not possible." Hagadorn suggests Anomalocaris subsisted on a softer diet of jellyfish and worms, or maybe just filtered plankton. In turn, Hagedorn's colleagues insist that his is not the last word on the matter. Says Dave Rudkin of the Royal Ontario Museum, "What we need is to find Anomalocaris poop."