The deadly threat posed by German submarines during World War I helped spur scientists to develop sonar, using underwater sound signals to locate objects like subs.
It was an important breakthrough, but it was old technology as far as whales go. These marine mammals have been using echolocation — bouncing high-frequency sounds off underwater objects — to find prey for tens of millions of years.
U.S. scientists Wednesday announced the discovery of the most ancient whale known to have used echolocation — a creature called Cotylocara macei, which lived about 28 million years ago and was a bit larger than a bottlenose dolphin.