A sprawling seagrass meadow has just been declared the "world's largest single living organism" based on area. The Poseidon’s ribbon weed seagrass (Posidonia australis) is located in Shark Bay, a protected body of shallow water in Western Australia. It covers an impressive 77 square miles (200 square kilometers) — the equivalent of about 280 soccer fields! The record was previously held by a 3.7 square-mile mushroom, dubbed "Humongous Fungus," in the Malheur National Forest in Oregon, USA.