Largest organisms
The Great Barrier Reef is the world's largest structure composed of living entities, stretching 2,000 km (1,200 mi) but contains many organisms of many types of species.
When considering singular entities, the largest organisms are clonal colonies which can spread over large areas.
Pando, a clonal colony of the quaking aspen tree, is widely considered to be the largest such organism by mass.
The largest organism in the world, according to mass, is the aspen tree whose colonies of clones can grow up to 8 kilometres (5 mi) in size.
[21][22] The upper estimates of weight for these prehistoric animals would have easily rivaled or exceeded the largest rorquals and sauropods.
[26] A mushroom of this type in the Malheur National Forest in the Blue Mountains of eastern Oregon, U.S. was found to be the largest fungal colony in the world, spanning 8.9 km2 (2,200 acres) of area.
[27] Approximations of the land area of the Oregon "humongous fungus" are 3.5 square miles (9.1 km2) (2,240 acres (910 ha), possibly weighing as much as 35,000 tons as the world's most massive living organism.
[28] A spatial genetic analysis estimated that a specimen of Armillaria ostoyae growing over 91 acres (37 ha) in northern Michigan, United States weighs 440 tons (4 x 105 kg).
The largest known fruiting body of a fungus is a specimen of Phellinus ellipsoideus (formerly Fomitiporia ellipsoidea) found on Hainan Island.
The largest known species of bacterium is named Thiomargarita magnifica, which grows to 1 cm (0.39 in) in length,[42] making it visible to the naked eye and also about five thousand times the size of more typical bacteria.
[45] According to a study coauthored by Jean-Marie Volland, a marine biologist and scientist at California's Laboratory for Research in Complex Systems, and an affiliate at the US Department of Energy Joint Genome Institute, T. magnifica can grow up to 2 centimeters long.
[46] The largest virus on record is Megaklothovirus horridgei, with the length of 4 micrometres, comparable to the typical size of a bacterium and large enough to be seen in light microscopes.
