with gigantic marine reptiles such as the Megalodons and Liopleurodons. The land on

the other hand was ruled by the dinosaurs. Creatures like the famous Tyrannosaurus rex

and Triceratops. Then something happened. Something that would cause 75% of the life

on this planet to go extinct. It is known as the K-T or K-Pg extinction and what's so

remarkable with this particular mass extinction is how quickly it occurred. It was not a gradual

process but instead seemed to have been triggered by a single event. An asteroid impact. The

asteroid created a crater over 180 kilometers wide and 20 kilometers deep, located here

at the edge of the Gulf of Mexico. And while this asteroid meant the end for much of the life here on

Earth, it could possibly have meant the beginning for new life elsewhere in the universe. Simulations

of the impact shows that vast quantities of large chunks of Earth was launched into space

at incredible speeds. Many of these pieces had the capacity to shelter tiny living organisms

for millions of years in the cold darkness of space. Simulations also show that some

of them had the potential to collide with other bodies like Mars and even as far out

as the moon of Jupiter, Europa. So even though the chances of that actually happening is

ridiculously small and just next to impossible. It's not truly impossible that space dinosaurs

actually exist.

While it's often said that dinosaurs went extinct around 66 million years ago, it's

not really true. What really happened is that all non-avian dinosaurs went extinct. Meaning

that, taxonomically, modern day birds (like a chicken for example) are dinosaurs just

as much as the T-rex was. In fact, the relation between birds and dinosaurs are much stronger

than we once thought. If you examine the embryo of a chicken and how its bones and body develop,

you'll find a very close resemblance to many long extinct dinosaurs. Chickens and many

other birds still have characteristics like a long tail, hands, claws, and even teeth.

It's just that it's hidden within their genetic coding and never actually develop. However,

scientists are working on, sort of, reactivating these genes which could mean that in the not

so distant future we'll see something like a Chickensaurus.

Many dinosaur and bird fossils have been found in what's become known as "the death pose".

The pose consists of their neck being dramatically bent backwards, their tail extended, and mouth

wide open. Why and how this occurs has been the subject for debate for many decades now.

For the longest time, experts believed that the animals simply could bend this way in

real life. But that seems unlikely, and it's more reasonably caused by something after

death. The most likely theory is that the ligaments in their bodies shrink once they

start to decompose and thus the death pose is formed.

The group of dinosaurs known as Titanosaurs were, as the name implies, some of the largest

dinosaurs we've ever discovered. In fact, they are probably the largest terrestrial

animals to have ever existed on Earth. Quite literally titans. Some of the largest in this

group doesn't even have official names yet and could grow to become 40 meters long and

20 meters tall. Their necks being so elongated that if they held it too high for too long

they could pass out as their heart struggled to pump blood all the way up to their brain.

The most astounding fact is that they could have weighed anywhere from 70-100 tonnes.

That's roughly 15 of the heaviest elephants you can find squeezed into one single beast

of an animal.

Micropachycephalosaurus is the longest generic name for any dinosaur so far. It means "small

thick headed lizard" and the fact that it has the longest name is a bit ironic given

that it's one of the smallest and shortest dinosaurs found at only 1 meter long.

Giant herbivorous dinosaurs known as Sauropods would roam the Earth during the Mesozoic Era

and spend their entire life eating plants and various kinds of foliage. Their bodies

were so ginormous that they didn't even have time to orally process their food like we

humans do. Instead, their head and jaws functioned as simple harvesting tools to get plants into

their bodies as quickly as possible. The stomach then took on the responsibility for processing

and digesting these whole pieces of food. But doing it this way created a lot of methane,

or in other words, dinosaur farts. Sauropods alone, not including any other dinosaurs,

are estimated to have released around 520 million tonnes of methane into the atmosphere

every year. That's almost as much gas that we humans are able to naturally and artificially

produce today. All from just one single group of reptilian rectums. Dinosaurs essentially

terraformed a planet with their ass.

It's long been known that most dinosaurs didn't look like this. With sort of leathery skin

similar to a lizard. Instead, most dinosaurs had feathers covering their entire bodies.

It's been proven time and time and again and even the T-rex had feathers. The question

is why though? I mean, we now know that birds are in fact dinosaurs but birds use the feathers

to fly. As far as we can tell, the T-rex could not fly. That would be scary as shit though.

So as feathers mysteriously appeared long before any birds or flying animals used them

for flight, what was their original purpose? Well, paleontologists and other experts believe

they were used to communicate. More specifically, to attract females and to show how much of

a boss you are with all them fancy-ass colors. This is also supported by the fact that dinosaurs

enjoyed a much more complete visual range than we humans do and could perceive even

more colors and thus obtain even more fabulous feathery dino friends.

The Stegosaurus is known for it's weird looking plates on its back. And experts agree, it

is weird as we can seem to figure out what purpose they served. One fascinating theory

is that the Stegosaurus could control its body temperature by regulating blood flow

through them. The idea is that if it was really hot or cold outside, blood would start gushing

in and out of the plates to keep an even temperature. It's called thermoregulation and we humans

do this as well. But instead of plates on our back, we for example sweat.

Plates would be pretty cool though.

Quetzalcoatlus. Ok, only the 38th time I'm trying to pronounce that name. Seriously,

who uses a Q and a Z in the same fucking word. I'm looking at you.. quartz? Quetzalcoatlus

was a flying reptile that existed during the Cretaceous period of the Mesozoic Era. It

is the, without question, largest flying animal to have ever lived. They had a wingspan of

up to 12 meters and weighed between 200-250 kilos. It would be like seeing a lightweight,

living, breathing fighter yet flying around.

Throughout this episode you might have noticed me using the word reptiles and dinosaurs in

different situations. The reason is that while animals like these and these are often referred

to as dinosaurs, they are technically not. The definition of what is and isn't a dinosaur

is a bit complicated and usually involves various anatomical differences. What you need

to know is that around 252 million years ago their was an extinction event called the "Great

Dying". This event killed almost everything. It is the most severe of all of the major mass

extinctions, killing up 96% of all species on the planet. This event marked the beginning

of the Mesozoic Era. It would last until the next extinction event that occurred around

66 million years ago when an asteroid wiped out the dinosaurs. This marked the end of

the Mesozoic Era. Almost every egg-laying, land-dwelling, reptilian creature that existed

during this period is a dinosaur with a few exceptions. This means that sea creatures

and flying animals from the Mesozoic Era are not dinosaurs but instead regarded as marine

and flying reptiles. However what they all have in common is that they are all descendants

of archosaurs.