For more than 170 years, paleontologists have puzzled over the origin of the strangely uniform hexagonal tunnels preserved in fossils. A new study published in Earth Science Reviews offers a fresh answer to this long-standing mystery.
After reviewing the evidence, the researchers concluded that the tunnels were most likely made by small crustaceans, not the worms that some earlier hypotheses had proposed. The study adds a new chapter to the ongoing effort to identify the creatures behind these nearly perfect hexagonal traces.