Mammals see with their eyes, hear with their ears and smell with their nose. But which sense or organ allows them to orient themselves on their migrations, which sometimes go far beyond their local ...

518-million-year-old fossil reveals vertebrates once had four eyes and extra organs that later shaped evolution.

TimesMachine is an exclusive benefit for home delivery and digital subscribers. About the Archive This is a digitized version of an article from The Times’s print archive, before the start of online ...