Scientists discover a 24-legged insect that had been mistaken for a crustacean

For decades, scientists classified the 324-million-year-old fossil as a crustacean. New research has now identified it as Chosha praecursor, a previously unknown insect with 24 legs.

The creature’s body plan challenges the familiar image of insects as six-legged animals. Its unusual anatomy is also drawing attention because it may help scientists examine a longstanding biological question: how animals moved from water onto land.

The fossil’s reclassification turns an old specimen into evidence for studying one of the major transitions in animal evolution.