What are the biggest creatures?

What are the biggest living things? This is a great question, it is one of the first that kids ask when they start learning about the natural world.

The biggest animal to ever exist is the Blue Whale. No dinosaurs or any other extinct animal was ever larger. It is an amazing thing that we take for granted, that across the three billion of life on Earth, we just happen to live at the same time as a Blue Whale, a 33-meter long animal that has blood vessels large enough to swim through and a heart the size of a car.

However, there are lots of other amazing massive creatures that are alive today that are bigger than the Blue Whale. Let’s dive in, to planet Earth’s giants.

The Biggest Living Thing: Pando

The biggest living thing is Pando – a colony of Aspen trees in the United States. The entire thing is one giant living organism that has probably been alive for a few thousand years. It is just the most amazing thing and we need everyone to know about it (Image: Wikimedia).

When we think of big living things, we generally think of animals. It is part of our bias, being animals ourselves. However, the biggest living things are generally not animals, they are plants and fungi.

We should note there are a couple of different ways to measure “biggest”. Do we mean “heaviest”? Or “longest”? Or that takes up “the most space”? There are different answers to some of these questions.

The heaviest living thing on Earth is definitely Pando. Pando is a colony of quaking aspen trees in Colorado in the United States. The colony covers 46 square kilometers and likely weighs over 6,000 tonnes and is definitely at least a few thousand years old. To be clear, Pando isn’t one tree, above the ground, it looks like one large forest of very similar-looking trees. However, underneath the ground, there is one continuous root system, the trees are really just its above-ground sprouts, like blades in a tuft of grass. Pando can share water, nutrients across its entire area and individual trees dying do not mean Pando dies. Also genetic testing has identified that every single tree has the same genetic material – it really is just one massive organism.

Now you could be thinking – eh that’s lame, it’s just some trees. You would be wrong. The fact that most of Pando is below the ground and it looks like separate trees does not make this ancient wonder anything less incredible. It is probably older than your country, language and maybe even all human languages and human civilization itself. It is definitely bigger than your street and suburb, maybe even your entire city. And it is constantly managing an entire lake’s worth of water which it is pumping around its body trying to ensure each of its little tree shoots survive. Pando is an epic wonder of our planet and any other view is just wrong.

Also most sadly, it looks like Pando is dying. And no surprise who is responsible for that (it’s humans). Pando is not particularly well protected by the American government. For instance, Pando is subject to a large amount of cattle grazing and has been affected by pollution in the surrounding areas. This combines together to mean that Pando is not putting out very many new shoots and those that are being put out, are being eaten by animals. No real conservation efforts seem to be taking place, and despite all its glory, very little of Pando is well understood or even being studied.

These images show 72 years of history of Pando through satellite imagery. The images show that the area it covers has slowly been reducing in size and getting thinner – mainly through the grazing of large animals such as deer and cattle. Pando is now covered in large numbers of powerlines, hiking trails and cabins, you can see a road running right through it in the image as well (Image: Utah State University).

The Biggest Plant: General Sherman

General Sherman is the largest single tree in the world. He is a giant sequoia, in a massive forest of sequoias in California the United States. He’s not actually the tallest, that honor goes to the Hyperion tree, a tree whose location is kept secret to protect it (fair enough – see what we’ve been doing to Pando above).

General Sherman is 83 meters tall and 8 meters wide. He is probably about 2,500 years old and was named after the American Civil War General William Tecumseh Sherman. The official story, (which might not be true) claims the tree was named in 1879 by a biologist James Wolverton, who had served under Sherman in the War. The tree is now a major tourist attraction with an entire national park devoted to General Sherman and his surrounding colleagues.

Despite the national park, General Sherman is under threat. The larger number of wildfires that have been occurring in California over the last few years due to climate change have started to threaten the national sequoia forests. Specific teams of firefighters have been sent out to protect General Sherman, doing things like installing sprinkler systems to keep the entire surrounding area wet and covering the base of General Sherman in fire-retardant blankets. These efforts have so far been successful, however as of writing this blog in September 2021, the fires are within a few kilometers of the General. It’s very possible it will burn down in the next few years.

General Sherman being protected by firefighters in recent California wildfires. The fires in 2021, as of the time of this blog post, are within a few kilometers of the General (Image: National Park Service Fire and Aviation).

The Biggest Dinosaur: Dreadnoughtus

The largest dinosaur is hard to estimate. The problem is, we only have incomplete skeletons for most dinosaurs. And even for those that we have complete skeletons, we don’t really know what its soft tissue looked like. So estimating weight is hard. It was definitely a sauropod – one of the long herbivores like diplodocus. They were all much larger than other types of dinosaurs, even the large predators like T-rex, which look tiny compared to them.

The largest dinosaur we can reliably estimate the size of is Dreadnoughtus Schrani. Dreadnoughtus was discovered from two reasonably complete skeletons in Argentina and probably lived around 70 million years ago. It weighed at least 40,000kg and at 26 meters long, was longer than most planes. It was so big, that originally excavating it required an entire team, and eventually, four mules attached to ropes to pull the bones out of the ground. Its name, dreadnoughtus, means “fears nothing” because once it was even half-grown, not even the largest predatory dinosaurs would have been a threat to it.

Now it’s pretty obvious dinosaurs were big. A lot of people know that. But it’s easy to just gloss over that, and not really have it sink in. Just imagine how big Dreadnoughtus would have seemed if you were standing next to it. You would come up to the bottom of its ankle. Its head would be at the height of a six-story building. Imagine how much it would eat and drink? We are talking about probably multiple trees worth of leaves every day and a forest roughly every month. Imagine it walking onto a beach for the first time and splashing down into some water? Now realize there were probably thousands of them and hundreds of other species of a similar size, wandering the Earth. The history of our planet is truly incredible.

Other Big Living Things: Some honourable mentions

This is Posidonia oceanica – also known as “Neptunes Grass”. It lives in giant colonies on the seafloor in the Mediterranean Sea. However, one colony is one giant single organism, like a tuft of grass you see around you on an oval. There is one patch of Neptune’s Grass near Greece that covers 8 kilometers – and can absorb more than 15 times the amount of carbon than an equally size patch of Amazon rainforest (Image: Frédéric Ducarme, Wikimedia).

There are a lot of other weird and wonderful massive creatures on the planet.

For example, there is a massive fungus that covers about 8 square kilometers in Oregon’s Malheur National Forest. This makes it pretty close in size to Pando and a competitor as one of the world’s largest organism (we are rooting for Pando here at The Universal Story). It has been amusingly nicknamed the humongous fungus and was only discovered about 25 years ago (see image below).

There is a single seaweed colony off the Greek island of Ibiza that is one organism that covers 8 kilometers. It is probably at least 100,000 years old and absorbs more carbon dioxide, offsetting climate change than any other organism, probably more than any single forest (image above).

There is also this poisonous 55-meter long worm. It floats around in the ocean, minding its own business, and is only about a centimeter wide, but is longer than any other animal, including the blue whale. The entirety of its body is covered with a highly toxic mucus, so toxic it can kill cockroaches and crabs.

See more on what we at The Universal Story consider is the best Wikipedia page, the “Largest Organisms” page.

Giant life: Some final thoughts

These are some images of the Humungous fungus in Oregon’s Malheur National Forest. It is almost certainly one of the largest organisms in the world – covering at least 6 square kilometers, and weighing at least as much as 200 blue whales. It is actually quite destructive, it has been spending the last few hundred years infecting and destroying trees from inside. It is linked together underground by tiny little shoestring-like root structures (bottom), thousands of which combine together under the forest like a web. Once the web finds a new tree it then sends up mushrooms above the ground to attack and destroys trees from the inside, eventually digesting them and returning them to the soil (top) (Image: *Nick Fisher / OPB*).

When we think of living things, we are really biased. We think of animals, normally brightly colored ones, like lions and tigres. They are about our size, similar us – they eat, breathe, and move around and exist on a similar timescale. They are very relatable. And these animals are great, we love them. But life on Earth is a lot more diverse than this.

Most of the living things on Earth are not like us. All living things have their own different timelines, ways of living and interacting with the world. Whether they be insects which live only a few days, or trees and forests which live hundreds of years. Or plants that get their energy from the sun, or fungi that digest rotten organic matter, returning it to the Earth. All these creatures play a fundamentally important role in ecosystems and life on Earth. We shouldn’t disregard them because they are not exciting and cool like us, sitting at a desk and writing emails during the week.

It is amazing to think there are probably people who live near Pando in the US, who have no idea what it is. You could live in the region your entire life, walk through the forest every weekend and not realize you were walking through the largest living organism. Or go for a holiday in Greece and scuba dive through that seagrass and not realize you were swimming through a single underwater forest older than human civilization itself. We, here at The Universal Story, think it would be better if we tried to open our eyes a bit wider to the natural world. There is so much weird and wonderful beauty out there on our Planet. You just need to look beyond yourself, and your notions of life, and actually see it.

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