Largest organisms

The largest organisms found on Earth can be determined according to various aspects of an organism's size, such as: mass, volume, area, length, height, or even genome size. Some organisms group together to form a superorganism (such as ants or bees), but such are not classed as single large organisms. The Great Barrier Reef is the world's largest structure composed of living entities, stretching 2,000 km, but contains many organisms of many species. The organism sizes listed are frequently considered "outsized" and are not in the normal size range for the respective group.