A giant head and gill-covered body make this newly reconstructed creature (pictured) "one of most bizarre fossil creatures that there is," one scientist said. The 505-million-year-old critter was first identified in 1912 from fossil pieces. Over the years, bits of it showed up in museum collections mislabeled as jellyfish, sea cucumbers, and various other creatures. But expeditions in the 1990s began to uncover more complete specimens, which suggested the animal, dubbed Hurdia Victoria, was much more unique than previously thought. Now, a well-preserved specimen found in the collections of the Smithsonian National Museum of Natural History in Washington, D.C., and...