When we think of big dinosaurs, it's hard to ignore some of the classic stars like T.rex and Spinosaurus.
But dinosaurs got way, way bigger!
But which were the biggest of them all?
Let's start with a human and the heaviest land animal around today... an elephant.
We all know who wins this one.
Even though the legendary T. rex was longer than an elephant, it weighed about the same.
And a Spinosaurus would only just tip the scales.
The real super-stars of the show are the sauropods.
Sauropods are dinosaurs that walked on four legs, had long necks and tails and ate plants.
A Diplodocus could have been twice the weight of a Spinosaurus but that’s just getting started.
Meet Supersaurus!
This hefty herbivore was double the weight of a Diplodocus
and may have maxed out at 36 tonnes, or seven elephants.
But the colossal crown goes to a group of sauropods called titanosaurs.
Introducing Puertasaurus, Patagotitan and, perhaps the heaviest of them all, Argentinosaurus,
weighing in at up to 70 tonnes, as much as 14 elephants.
What allowed these titanosaurs to grow so big?
Firstly, titanosaurs had a strong, stable body shape, including four pillar-like legs,
sturdy joints and wide-set hips.
These features not only helped to carry their mega mass but also provided support for their sizeable stomach.
And the bigger the belly the more energy and nutrition for these giants.
Reaching enough food wasn’t a problem for the titanosaurs and other sauropods either.
With long necks and small heads, they could forage high and low for the best plants around.
Another secret of their size lies inside their bones.
Unlike most other reptiles, titanosaurs had some bones that were hollow and filled with air.
This made them much lighter than they would have been otherwise.
Other animals, like whales, have solid bones, meaning they would be much heavier for their size.
If you had a whale and a titanosaur of the same length, the titanosaur would weigh much less.
The only reason today’s blue whales can get so big with solid bones
is that they live in water, which helps to support their weight.
All of these different body features combined were a big part of titanosaurs growing so large,
but one other key element was their mighty metabolism!
Metabolism is how food becomes energy, and eventually waste.
Because of titanosaur's size, their metabolism was very energy efficient.
They could eat plants that other animals might struggle to digest.
Not only that, but they were brilliant breathers.
Unlike humans who only receive oxygen when they breathe in,
these dinosaurs had air sacs which worked with their lungs to supply them with oxygen
even when they breathed out!
But was being the biggest land animal as good as it seems?
Being big meant these dinosaurs were better able to protect themselves from predators.
And they could reach food where others couldn’t.
It also meant more fat, which could be useful in harsh times.
Not only that, but larger animals take bigger steps
and can travel longer distances,
so they find more food, water and even mates.
But being big wasn't all good.
There were some disadvantages.
It's easier to overheat if you have a large body.
Although titanosaurs like Patagotitan
did have special features to help keep them cool.
And the need for lots of food could be bad news for a species if there was a sudden,
environmental change on a global scale.
As energy efficient as titanosaurs were, bigger animals need more food than smaller ones.
If a food shortage went on for a long time, with not much around anywhere,
large animals would struggle to find enough food to eat.
In the end, the bigger dinosaurs were more vulnerable to extinction.
Only some small dinosaurs survived, we call them birds.
While we no longer have dinosaur giants roaming our lands,
we are lucky to share our planet with our own colossal creatures.
However, just like titanosaurs, their size makes them more vulnerable to habitat loss,
food shortages and climate change.
But perhaps through positive action we can make sure modern-day giants don't just survive but thrive.
You never know, maybe in the very distant future,
with the perfect balance of features to help it grow big,
an animal species might just evolve to be supersized.
But it’s unlikely any would quite fill the shoes of the titanosaurs.