It’s one of evolution’s most eccentric creations: a head shaped like a hammer. Now, a study suggests that the hammerhead shark may have evolved its oddly shaped snout to boost the animal’s vision and hunting prowess.

For over a century, scientists have speculated why hammerheads evolved such an odd shape and whether having eyes so far apart would enhance their vision.

Now, hammerhead sharks have had their first eye examination, and it has laid the debate to rest. Sharks with wider heads have better binocular vision – all the better to track fast-moving prey like squid with far more accuracy than sharks with close-set eyes. The research also shows that hammerheads – among other sharks – have a 360-degree view of the world in the vertical plane, allowing them to simultaneously see prey above and below them.

Previously, researchers have theorised that the hammerhead’s head may improve its sense of smell, boost its ability to locate prey using electric fields, improve its manoeuvrability or help it to pin down struggling rays so it can bite off their wing-like fins.