Which lizard is the only modern species known to forage in the ocean?

The marine iguana is the only modern lizard known to forage in the ocean.

Marine iguanas live only on the Galápagos Islands, where they feed mainly on algae growing in shallow seawater. They swim using sideways body movements and paddle-like tails, then return to land to warm themselves in the sun.

Their unusual lifestyle requires several special adaptations. Flattened bodies and long claws help them cling to rocks in surf, while dark coloration helps them absorb solar heat. They can also expel excess salt through glands near their noses, often producing visible “salt sneezes.”

Marine iguanas are sometimes confused with sea snakes or marine turtles, but they are reptiles that still breathe air and must surface after dives. Charles Darwin described them during the voyage of HMS Beagle, calling them hideous-looking but highly distinctive animals.