The Mesozoic Era

What happened?

The Triassic-Jurassic extinction, also called the end-Triassic extinction - it profoundly affected life on Earth, both on land and in the seas, as up to 80% of all land and marine species perished.

When did it happen?

201 million years ago

How did it happen?

While the exact cause is still under debate, many scientists believe that volcanic activity along the Central Atlantic Magmatic Province triggered a release of massive amounts of greenhouse gases. This area covers 11 million km² and today, its legacy of lava can be seen spread out over a vast area around the North Atlantic Ocean, northwest Africa, southwest Europe, as well as northeast South America and southeast North America. Evidence points to a 600,000 year long period of volcanic activity, with the first 40,000 of particular intensity. By the Early Jurassic period, these eruptions cause Pangaea to split and begin to break up; the northern half to become Laurasia with the southern half becoming Gondwana. During this time, Earth warmed as much as 10-15 degrees Centigrade, saw quadruple CO₂ levels and the oceans acidified.

Another common theory is that an asteroid or meteor struck the Earth, and there is lots of evidence to support small asteroid strikes at that time. Other experts believe that climate change was the cause.

The linked video looks at each of these theories in more detail.

What happened?

The Cretaceous-Tertiary extinction is also called the K-T extinction, K-Pg extinction or Cretaceous-Paleogene extinction and it wiped out 76% of all species on the planet, including all non-flying dinosaurs.

When did it happen?

66 million years ago

How did it happen?

Though still widely debated, some experts believe that the dinosaurs met their demise at the hands of a massive asteroid. The Chicxulub crater in Mexico is estimated to be 180km in diameter and 20km deep and was formed when a large asteroid, roughly 10km in diameter, struck the Earth. The disappearance of the dinosaurs coincides with the date of impact of the asteroid and many believe that the climate disruption and devastation from the impact was the driving force behind it.

Other theories include global warming due to volcanic activity at the Deccan Flats in India as some evidence points to a massive die-off of dinosaurs before the asteroid hit Mexico which could coincide with a massive volcanic eruption. Still more believe that a combination of both events resulted in the disaster. Check out the videos for some unique perspectives.