Largest organisms
From the sprawling forest floor to the deepest oceans, life on Earth has evolved to astonishing scales, manifesting in forms both familiar and utterly alien. But how do we truly measure the "largest"? Is it by weight, height, or the vastness of an interconnected network? Join us as we explore the colossal wonders that redefine our understanding of what a single living entity can be. Many of Earth's largest organisms are not single individuals but vast, interconnected clonal colonies spanning miles. The sheer size of certain fungi and marine plants often goes unnoticed, hidden beneath soil or ocean waves. Even in the microscopic world of bacteria and viruses, there are true giants that challenge our perception of their scale.
AI Summary
From the sprawling forest floor to the deepest oceans, life on Earth has evolved to astonishing scales, manifesting in forms both familiar and utterly alien. But how do we truly measure the "largest"? Is it by weight, height, or the vastness of an interconnected network? Join us as we explore the colossal wonders that redefine our understanding of what a single living entity can be.
- Many of Earth's largest organisms are not single individuals but vast, interconnected clonal colonies spanning miles.
- The sheer size of certain fungi and marine plants often goes unnoticed, hidden beneath soil or ocean waves.
- Even in the microscopic world of bacteria and viruses, there are true giants that challenge our perception of their scale.
The Titans of Earth
When we talk about the "largest organisms," the criteria can be surprisingly diverse. Do we mean the heaviest, the tallest, the longest, or perhaps the one covering the greatest area? This fascinating quest often leads us to consider different metrics, and sometimes, even exclude what appear to be vast communities, like a coral reef or an ant colony, which are actually made up of countless individual organisms.
Our journey begins with the true titans: clonal colonies. These are organisms that reproduce asexually, creating genetically identical copies that remain connected, often by an intricate root or fungal network. By sheer mass, one of the most famous examples is Pando, a vast grove of quaking aspen trees in Utah, widely believed to be the world's most massive single organism. What looks like a forest is, in fact, one giant tree.
But Pando isn't alone in its sprawling grandeur. Off the coast of Western Australia, a colossal marine plant, Posidonia australis, has been discovered covering an astounding 200 square kilometers—that's about 77 square miles! This single seagrass clone stretches an incredible 180 kilometers in length, making it the largest organism by area ever known.
Even older and incredibly expansive is another seagrass, Posidonia oceanica, found near Ibiza in the Mediterranean. This colossal colony spans 8 kilometers and is estimated to be around 100,000 years old. Imagine a single organism that has quietly thrived for an entire ice age, a testament to nature's enduring power.
Individual Plant Powerhouses
While clonal colonies redefine scale, individual organisms also reach astonishing sizes. Among single-stem trees, the giant sequoia (Sequoiadendron giganteum) reigns supreme by wood volume and mass. These magnificent conifers, native to California's Sierra Nevada, can soar to heights of 70 to 85 meters—over 250 feet—with trunks up to 7 meters in diameter. Think of a living skyscraper, but made of wood!
Animal Goliaths
Turning to the animal kingdom, the ocean is home to the most colossal creatures. The blue whale (Balaenoptera musculus) is not only the largest living animal but is believed to be the largest animal to have ever lived on Earth. Reaching lengths of over 30 meters and weighing up to 200 tons, its heart alone can be the size of a small car, and its tongue weighs as much as an elephant.
On land, the African bush elephant (Loxodonta africana) holds the title for the largest living terrestrial animal. These majestic giants can weigh over 6 tons. However, if we look back in time, some dinosaurs, like the long-necked sauropod Bruhathkayosaurus, may have been even larger land animals, potentially dwarfing any creature walking today.
The Hidden Networkers: Fungi
Prepare to be amazed by the hidden giants beneath our feet. The largest living organism in the world by area, and potentially mass, might just be a fungus—the honey fungus (Armillaria ostoyae). These fungi spread extensive networks of thread-like structures called mycelia through soil, connecting individual mushrooms across vast distances. One such specimen in eastern Oregon is nicknamed the 'Humongous Fungus'.
This particular Armillaria ostoyae colony in Oregon's Malheur National Forest sprawls over an astonishing 8.9 square kilometers, an area larger than many towns! It's estimated to weigh up to 35,000 tons and could be 2,400 years old. While its individual mushrooms are small, the true organism is the enormous, interconnected network below ground, making it a true silent titan.
Another massive Armillaria ostoyae specimen has been identified in northern Michigan, covering 91 acres and estimated to weigh 440 tons. These fungal networks represent a unique form of large-scale life, quietly dominating vast ecosystems from below the surface.
Singular Spores
While the honey fungus is a colossal colony, individual fungal fruiting bodies can also reach impressive sizes. The largest known fruiting body of a fungus belongs to Phellinus ellipsoideus, discovered on Hainan Island. This remarkable specimen can mass up to 500 kilograms—over 1,100 pounds! It's less of a mushroom and more of a woody, shelf-like structure.
Before Phellinus ellipsoideus took the crown, the largest individual fungal fruiting body was Rigidoporus ulmarius. This fungus could grow to an imposing 284 kilograms, standing 1.66 meters tall and stretching 1.46 meters across, with a circumference that could encircle a small car.
Floral Extremes
Even among flowering plants, there are notable giants. The largest individual flower in the world is the magnificent Rafflesia arnoldii, known for its massive, malodorous bloom that can measure nearly a meter across. Meanwhile, the Amorphophallus titanum, or 'corpse flower,' boasts the largest unbranched inflorescence—a cluster of flowers—reaching several meters in height, both native to Sumatra.
Algae's Green Grandeur
Even among the simpler green algae, some species achieve impressive lengths for single-celled organisms. The unicellular 'mermaid's wineglass' (Acetabularia) can grow to several inches, while the fronds of the similarly unicellular Caulerpa taxifolia can reach up to a foot long. These organisms are truly large for being composed of just one cell!
Microscopic Marvels: Protists
The category of Protista, though not strictly used in modern taxonomy, traditionally encompasses a fascinating array of eukaryotic organisms that aren't animals, plants, or fungi. Among these, the giant kelp (Macrocystis pyrifera) stands out as the largest. These magnificent brown algae form vast underwater forests, with floating stems that can stretch over 45 meters, making them the largest protist, chromist, and brown alga overall.
Other protist giants include the slime molds, such as Physarum polycephalum, which can reach diameters over 30 centimeters—remarkable for an organism that is unicellular but multinucleate. Even more astonishing are giant amoeboids like the xenophyophore Syringammina fragilissima, a deep-sea creature that can grow up to 20 centimeters, and the heliozoan Berkeleyaesol magnus, whose sphere can reach over 6 millimeters, visible to the naked eye.
Bacteria Breaking Barriers
When we think of bacteria, we usually imagine microscopic specks. But Thiomargarita magnifica shatters that perception. Discovered in 2022, this bacterium can grow up to 2 centimeters long, making it visible to the naked eye and about five thousand times larger than typical bacteria. It's truly a marvel, resembling a human eyelash in size and shape.
Among the 'blue-green algae,' now known as cyanobacteria, there are also sizable filamentous forms. Lyngbya, for example, can have cells that are 50 micrometers wide, forming filaments that are much larger and easily observed under a standard microscope.
Ancient Architects: Archaea
Archaea, another domain of single-celled organisms, also boast their own giants, though on a smaller scale compared to bacteria. Staphylothermus marinus, a heat-loving archaeon, typically measures 0.5 to 1 micrometer, but under certain conditions, it can grow to cell diameters of up to 15 micrometers—making it a behemoth in its own microbial world.
Viral Colossals
Finally, we venture into the realm of viruses, often considered the smallest life forms. Yet, even here, there are giants that defy expectations. The largest known virus is Megaklothovirus horridgei, measuring an astonishing 3.9 micrometers long. That's comparable to the size of many bacteria and large enough to be seen with a light microscope! Before its discovery, the Pandoravirus genus held the record, with viruses up to 1 micrometer in size and remarkably complex genomes.
Article
Largest organisms
Although it appears to be multiple trees, Pando is a clonal colony of an individual quaking aspen with an interconnected root system. It is widely held to be the world's most massive single organism.
This article lists the largest organisms for various types of life and mostly considers extant species, which 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 (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. Even if such colonies are excluded, trees retain their dominance of this listing, with the giant sequoia being the most massive tree. In 2006, a huge clonal colony of the seagrass Posidonia oceanica was discovered south of the island of Ibiza. At 8 kilometres (5 mi) across, and estimated at 100,000 years old, it may be one of the largest and oldest clonal colonies on Earth.
Among animals, all of the largest species are marine mammals, specifically whales. The blue whale is believed to be the largest animal to have ever lived. The living land animal classification is also dominated by mammals, with the African bush elephant being the largest of these.
Plants
Largest organisms
The Giant Sequoia (Grizzly Giant pictured) is the world's most massive tree
The largest single-stem tree by wood volume and mass is the giant sequoia (Sequoiadendron giganteum), native to California's Sierra Nevada; it typically grows to a height of 70–85 m (230–280 ft) and 5–7 m (16–23 ft) in diameter.
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. The largest such colony is Pando, in the Fishlake National Forest in Utah.
A form of flowering plant that far exceeds Pando as the largest organism on Earth in area and potentially also mass, is the giant marine plant, Posidonia australis, living in Shark Bay, Australia. Its length is about 180 km (112 mi) and it covers an area of 200 km2 (77 sq mi). It is also among the oldest known clonal plants.
Another giant marine plant of the genus Posidonia, Posidonia oceanica discovered in the Mediterranean near the Balearic Islands, Spain may be the oldest living organism in the world, with an estimated age of 100,000 years.
The largest individual flower in the world is Rafflesia arnoldii, while the flowering plant with the largest unbranched inflorescence in the world is Amorphophallus titanum. Both are native to Sumatra in Indonesia.
Green algae
Green algae are photosynthetic unicellular and multicellular "green plants" that are related to land plants. The thallus of the unicellular mermaid's wineglass, Acetabularia, can grow to several inches (perhaps 0.1 to 0.2 m) in length. The fronds of the similarly unicellular Caulerpa taxifolia can grow up to a foot (0.3 m) long.
Animals
Largest organisms
Bruhathkayosaurus is potentially the largest animal to have walked the earth.
Fungi
Largest organisms
Armillaria ostoyae
The largest living fungus may be a honey fungus of the species Armillaria ostoyae. 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 (3.4 sq mi) of area and possibly weighing as much as 35,000 tons. This organism is estimated to be 2,400 years old. The fungus was written about in the April 2003 issue of the Canadian Journal of Forest Research. It is not known, however, whether it is a single organism with all parts of the mycelium connected.
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).
In Armillaria ostoyae, each individual mushroom (the fruiting body, similar to a flower on a plant) has only a 5 cm (2.0 in) stipe, and a pileus up to 12.5 cm (4.9 in) across. There are many other fungi which produce a larger individual size mushroom. The largest known fruiting body of a fungus is a specimen of Phellinus ellipsoideus (formerly Fomitiporia ellipsoidea) found on Hainan Island. The fruiting body masses up to 500 kg (1,100 lb).
Until P. ellipsoideus replaced it, the largest individual fruit body came from Rigidoporus ulmarius. R. ulmarius can grow up to 284 kg (626 lb), 1.66 m (5.4 ft) tall, 1.46 m (4.8 ft) across, and has a circumference of up to 4.9 m (16 ft).
Lichen
Umbilicaria mammulata is among the largest lichens in the world. The thallus of U. mammulata is usually 4 to 15 cm (1.6 to 5.9 in) in diameter, but specimens have been known to reach 63-centimetre (2.07 ft) in the Smoky Mountains of Tennessee.
The longest lichen is Usnea longissima, which may grow to exceed 20 feet (6.1 m) in length.
Protists
Largest organisms
Macrocystis pyrifera, the largest species of giant kelp
(Note: the group Protista is not used in current taxonomy.)
Amoebozoans (Amoebozoa)
Among the organisms that are not multicellular, the largest are the slime molds, such as Physarum polycephalum, some of which can reach a diameter over 30 cm (12 in). These organisms are unicellular, but they are multinucleate.
Euglenozoans (Euglenozoa)
Some euglenophytes, such as certain species of Euglena, reach lengths of 400 μm.
Rhizarians (Rhizaria)
The largest species traditionally considered protozoa are giant amoeboids like foraminiferans. One such species, the xenophyophore Syringammina fragilissima, can attain a size of 20 cm (7.9 in).
Alveolates (Alveolata)
The largest ciliates, such as Spirostomum, can attain a length over 4 mm (0.16 in).
Stramenopiles (Stramenopila)
The largest stramenopiles are giant kelp from the northwestern Pacific. The floating stem of Macrocystis pyrifera can grow to a height of over 45 m (148 ft). Macrocystis also qualifies as the largest brown alga, the largest chromist, and the largest protist generally.
Heliozoa
As of 2021, the largest known heliozoan is Berkeleyaesol magnus (formerly Raphidiophrys magna): its axopodial sphere can reach a diameter up to 6350 μm (6.35 mm), with a cell body diameter of 1486 μm, a mucilaginous envelope 540 μm thick, and up to 1892 μm long axopodia.
Bacteria
Largest organisms
Thiomargarita magnifica with a tardigrade for scale.
The largest known species of bacterium is named Thiomargarita magnifica, which grows to 1 cm (0.39 in) in length, making it visible to the naked eye and also about five thousand times the size of more typical bacteria. BBC News described it as possessing the "size and shape of a human eyelash." Science published a new paper on the bacterium on June 23, 2022. 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.
One of the largest "blue green algae" is Lyngbya, whose filamentous cells can be 50 μm wide.
Archaea
Largest organisms
The largest reported archaea is Spaphylothermus marinus, with a cell diameter of up to 15 micrometres. Although it typically only achieves a diameter of 0.5-1 micrometres, cells with larger diameter may form when high concentrations of yeast extract are present.
Viruses
Largest organisms
A collection of viruses along with the bacterium E. coli, including M. horridgei - the largest virus
The largest virus on record is Megaklothovirus horridgei, with the length of 3.9 micrometres, comparable to the typical size of a bacterium and large enough to be seen in light microscopes. It was discovered in 2018 (being mistaken for bristles beforehand), having been found on an arrow worm in the genus Spadella. Prior to this discovery, the largest virus was the peculiar virus genus Pandoravirus, which have a size of approximately 1 micrometer and whose genome contains 1,900,000 to 2,500,000 base pairs of DNA.
Pandoravirus infects amoebas specifically, however Megaklothovirus infects Spadella arrow worms.