would say... THE BLUE WHALE OF COURSE! But, despite popular belief... it's not!

So, what on earth... is or should I say was?

I'm Stu, this is Debunked, and we're here to sort the truth from the myths and the facts

from the misconceptions.

Okay, so if the Blue Whale sets the benchmark by which all other living creatures are measured,

it probably makes sense to first establish just how BIG a Blue Whale can get?

The biggest one ever discovered was found in the Southern Ocean of Antarctica back in

1947. it weighed in at a hefty 190 metric tons (209.4 US TONS / 418,878 lb),

which is the equivalent to 104 standard family SUVs. It also measured a huge 27.6 meters

(90 ft 6 in) long, close to the length of a short haul airliner (Airbus 318)

and its estimated volume was roughly the size of 7 fuel trucks, at 223 cubic meters (7875

feet3). Remember that for later…

What could possibly out-size something this massive?

Well, whales first appeared around 40 million years ago, so to find out what could possibly

top such a titan,

it would make sense to take a look at this prehistoric era of Earth's history,

when great monstrous-sized beasts walked the planet,

plants were the size of VWs and colossal creatures swam in our oceans.

So, let's start with dinosaurs... or more accurately Titanosaurs

- a group of four legged veggiesaurus' with long tails and small heads.

The largest of these dinosaurs to have ever walked the Earth is believed to be the Argentinosaurus.

Its discovery in the 1990s stunned paleontologists the world over,

with a length of 35 meters and a weight of 70 metric tons (tonnes / 70,000kg)!

Put this next to most people's common point of dino sized reference - the T-Rex, and it

dwarfs the goat eating carnivore.

However the title was hotly contended in 2017 by the discovery of the Patagotitan mayorum.

This titanosaur was believed to have a skeleton 10% larger than the Argentinosaurus,

but recent weight estimations put it just shy at 69 tonnes.

Both Titanosaurs maybe longer than the whale, but put the Argentinosaurus

and the Patagotitan on a set of scales and the pair together wouldn't out weigh our

big blue heffer.

----

In fact, Whales are so much larger because they live in the ocean.

On land, animals suffer the full effect of gravity, but for sea based organisms;

the water's buoyancy reduces the strain on their muscles and skeletons, allowing them

to grow to such vast sizes.

When something as huge as a blue whale becomes beached or stranded on land,

their muscles can't support their body weight out the water and they will basically be crushed

to death under their own weight.

So with the ocean providing the best environment for a creature to super-size itself,

let's take a look in to the deep blue, and more specifically the Cretaceous period to

see what competition there would have been...

Now anyone who's witnessed this scene before will surely think that this prehistoric monster

offers some competition for a Blue Whale?

That, is a Mosasaur…

and THAT is a GREAT WHITE SHARK serving as an amuse bouche.

Now, if this is your average sized Great White then the Mosasaur would make up the length

of about 9 of these sharks.

With your average Great White measuring in at 5.3 meters, that means the Mosasaur measures

in at nearly 48 METERS!

And this is how our Blue Whale sizes up against this leviathan!

But here's where Hollywood gets carried away with itself…

Mosasaurs aren't believed to have grown any longer than 18 meters,

with the largest one to have been excavated sitting at a modest 15 meters,

meaning Jurassic World's reptile is grotesquely inaccurate.

Anyway that's enough science fiction, let's get back to the science fact.

What is the largest creature to have ever swam in our oceans?, Fortunately, a discovery

in 2018 may have the answer.

Measuring in at nearly 26 meters, that's only just short of our largest blue whale,

it's believed that this giant Ichthyosaur may have been the largest aquatic reptile

ever!

However, with its dolphin-like shape, a long pointy jaw and streamlined body, it's estimated

weight falls far below that of the Whale,

meaning the Blue Whale still stands as the largest animal to have ever swam in our planet's

waters.

Let's leave the wet stuff behind now and head back to land,

where the competition to be crowned largest living thing is starting to hot up.

What stands taller than the largest dinosaurs and doesn't suffer the effect of gravity

like other living, breathing organisms?

The trees…

As we travel to the coast of California, we'll find the Redwoods National Park,

and here you'll see, Hyperion!

Even fantasy doesn't top this living behemoth, take a recent incarnation of Godzilla and

put it next to the Sequoia,

and it stands around 10% taller at a staggering 115.85 meters!

And if Godzilla's not your thing then take a look at how the Statue Of Liberty sizes

up!

Yet, height isn't everything, we're after the largest and that doesn't necessarily

mean the tallest, so for that we need to travel down the coast to meet General Sherman,

a 2,100 year old Giant Sequoia. He may stand at a humble 82.6 meters (271 ft) tall by comparison,

but has a whopping volume of 1,487 cubic meters (52,513 cubic feet),

blowing old Bluey out of the water! Because in fact you could squeeze around 7 blue whales

inside this tree.

When the General's root system is taken in to account it's believed that this single

organism would weigh 1,814 tonnes (4,000,000 lb)!

And, as astounding as those stats are, there was once a tree larger than the General

, measuring 1,727 cubic meters, but it was sadly cut down in the 1940s.

However, even with these giants of the forest,

believe it or not we've still not found the largest thing to have ever lived on our

planet…

To find what we're looking for, we need to travel to the Blue Mountains Of Eastern

Oregon,

and here you won't find the largest living organism towering over the forest,

swimming through the lakes or stomping around the mountains.

Instead, we need to look below our feet. Under the forest floor of the Malheur National Forest,

you'll find something that you may not have expected to come out on top in this video.

While we've been looking at all the relevant Kingdoms of Life on planet earth,

there's one we're forgetting… Fungi (Fun-gee), OR Fungi (Fun-guy) or Fungi (Fun-jei),

depending on where you're from!

Here, on the ground, we find the Armillaria ostoyae, or more commonly known as the Honey

Fungus.

All that we generally see is the fruiting body, what we would consider a mushroom or

toadstool.

But this is often only 10% of a fungus, the rest of the organism, the vegetative part,

is below the earth.

To make this concept more familiar, imagine this as a fruit tree, and you'd see the

leaves,

branches and stems all below ground with only the fruit appearing above.

This fungus however is no ally to trees. The Honey Fungus is actually devouring the forest

from the ground up.

Now most people won't think of fungi as tree killers,

as they are in fact a cornerstone to the entire ecosystem of a forest,

usually breaking down organic debris like fallen leaves and transferring essential minerals

to the plants.

Here, however, the Armillaria ostoyae has a much more parasitic purpose.

It attaches itself to the forest's conifer trees and begins to feed off of their roots,

killing the tree in the process.

Nicknamed the Humongous Fungus, the wealth of trees in this area has enabled it to spread

far and wide,

and currently this fungi stretches across 2,200 acres or 8.9 square kilometers (3.4

square miles) below the soil!

To put what you are seeing here in to perspective, that is the equivalent...

of around 1,700 NFL football fields, or 36,500 tennis courts.

Now, the discovery of the Humongous Fungus sparked debate as to what constitutes a 'single

living organism'.

But it can be succinctly summed up by Biology Professor Tom Volk...

Which is exactly what the Honey Fungus is, meaning this is indeed a single living organism,

just like the Giant Sequoia or the Blue Whale.

And it's not just the extensive area it covers that makes the Armillaria ostoyae so

huge,

it's discoverer James B. Anderson from the University of Toronto recently surveyed the

site, and now estimates

that if the entire fungus were dug up out of the ground and weighed,

it would top the scales at 400 tonnes, more than double the heft of a Blue Whale!

But, as with anything at this scale, it brings with it some controversy.

There is another single organism spread over a vast area that is touting for the same title

of Largest Living Organism.

Head down to Utah and you'll find this huge tree…

...nope back out a little… there. This, is one, tree.

Known as the 'Trembling Giant' OR 'Pando' (Latin for “I, Spread.”)

this entire grove of 47,000 Quaking Aspen trees has grown from a single root system.

You see, Aspens find most success in regenerating 'vegetatively',

meaning sprouting from roots (not from seedlings), this results in what's termed a 'clone'.

Just like the Honey Fungus, this forest is genetically identical and it behaves as one

organism.

With the changing seasons, the whole forest changes color and sheds all its leaves in

unison.

And, most fascinatingly, as an old tree dies in the clonal grove, signals are sent from

the tree out to the network of roots,

which then stimulate new growth for the next generation to replace the old.

Now this colony may look substantially more impressive than the humble honey Fungus,

but... we're only looking at 106 acres.

Less than 5%, of the area covered by the Fungus.

So surely there's no competition? Well, the complications come when weight is included

in the criteria.

As we've learnt the Humongous Fungus weighs in at 400 tonnes, where as it's estimated

that Pando smashes through that record weighing a colossal six… thousand tonnes!

In fact the 'United States Department Of Agriculture' list the both Pando and the

Humongous Fungus as the 'Largest Organism On Earth'

So, surely the only way that this can be settled is to confirm it with the great holders of

such titles,

over at the Guinness World Records.

Well no, the record for 'Largest Living Organism' seems so controversial that even

Guiness haven't yet declared it.

According to their records, Pando is confirmed as the 'Most Massive Plant'

while the Honey Fungus holds the record for 'Largest Fungi'.

The most common criteria, however, that declares anything as 'Largest' is specified under

'Area Covered'.

And under this, the Humungus Honey Fungus is the outright winner.

Even if you took into account the total estimated volume of the two contenders

then the Armillaria Ostoyae decimates the Quaking Aspen at more than double its size.

Pando is however, believed to hold the slightly less grandiose record for

'Largest Known Organism On Earth In Terms Of Dry-Weight Mass'

as fungi are around 92% water. (Trees = 50% Water)

On the other hand, the Humongous Fungus has increased in size with subsequent surveys,

where as, sad but true, Pando is dying.

It has substantially reduced over the past 70 years due to human interference.

And, it's thought that within the next 10 to 20 years, up to 80% of the entire grove

could collapse.

Dr Paul Rogers, an Ecologist who recently led a conservation effort to protect Pando,

has said...