Dinosaurs were reptiles that varied in size and
shape. All dinosaurs had four legs and could
not swim nor fly. They were as big as the 30m
Argentinosaurus or as small as the 1m
Compsognathus. Dinosaurs appeared 231
mya during the Jurassic period and died at the
end of the Cretaceous period (66 mya). This
extinction was called the K.T (Cretaceous
*mya=million years ago
THE DINOSAURS HAD
THRIVED FOR 135
MILLION YEARS, BUT
WHAT LIVES MUST
*A theory is and idea meant to explain a certain
situation based on general rules or principles.
• Mammal competition
• Asteroid impact
• Continental drift
An extraterrestrial object (asteroid) 10km
across slammed into the Yucatan peninsula
creating the Chicxulub crater 65 million years
ago. Subsequently, forest fires, earthquakes,
tsunamis, drought and climate change
ravaged the planet.
Marking the end of the dinosaurs
100 million years before the collision a major
event occurred. In the asteroid belt, between
Mars and Jupiter, 320 million km away, an
asteroid 65 km across travelled another one
at 35,000 km an hour. It got pulverized into
‘tiny’ fragments. But one fragment -10 km
across - had a special destiny...to wipe the
dinosaurs off the face of the earth.
The asteroid consisted mainly of water and rock. The water,
in the cold vacuum of space, froze into permafrost.
Anything that passes through the Earth’s atmosphere
heats up and burns. Pieces of the asteroid broke off and
appeared as a meteor shower
believe that the water
and other chemicals in
asteroids was what
gave life to Earth.
But what gives life
can also take it
Just seconds away from impact there are some
key factors that scientists had to blame for the
extinction. Force is how much energy is
released during something. The mass of the
asteroid times the speed (70,000 km when
entering the atmosphere) equals massive
destruction. The force of the impact would be
100 million megatons. That’s more powerful
than all the world’s nuclear weapons combined.
Seconds after the asteroid hit, a sonic wave
was released in a perfect circle. This wave
killed any dinosaurs close to the impact site
and moved boulders! A massive dust cloud
was released during the impact and settled in
the upper atmosphere. This blocked out the
sun’s rays and first heated the planet, then
plunged it into a nuclear winter. Many events
occurred after this (which will be explained in
When the asteroid had hit, 1% of its force
(enough to shake the planet) had been
absorbed by the earth. This travelled around
the planet causing massive earthquakes. This
caused the landscape to move and created
cracks in the ground (in which water filled)
splitting some dinosaurs from the rest. This
led to breeding problems and soon some
species died off.
We all know what follows an earthquake; a
tsunami. These weren’t 2 metre waves: they
were several hundred metres tall and were as
thick as a house.
Due to the dust cloud blocking the heat in,
the air heated up which caused trees to go
ablaze. This led to massive fires killing
everything it touched.
It’s hard to imagined what could’ve survived
this disaster but things did survive. Many
mammals survived by eating insects and
aquatic plants which were in abundance
before, during and after the meteor hit. They
then massively multiplied and literally spread
everywhere in the world.
You may still be wondering about what
evidence scientists have to prove the
extinction theory. The evidence is in the
crater. Scientists believe that the Chicxulub
crater was the leftovers of the asteroid. In the
borders of the crater, a rare metal had been
found; iridium. It is similar to platinum but is
extremely rare on earth...but is found in
nearly every asteroid.
An asteroid 10 km wide smashed into earth
covering the atmosphere of the planet with
thick dust which blocked sunlight in. This
caused forest fires and the initial impact
caused earthquakes followed by tsunamis.
Some smaller species survived and evolved
into more complex things.
The team who found evidence of the theory
and created it consisted of: Luis Alvarez, his
son geologist Walter Alvarez, and
chemists Frank Asaroand and Helen Michel