Wednesday, February 25, 2015

G is for Gondwanaland

New Zealand—and all the landmasses on the planet—exist because the continents drift around the globe. All the land in today’s Southern Hemisphere was once part of Gondwanaland, which began to break apart some 200-180 million years ago, during the mid Mesozoic era. Good thing it did.

When Gondwanaland broke apart from the other supercontinent, Laurasia, it ended the one supercontinent, Pangaea. However, Gondwanaland was actually far older than Pangaea, having formed between about 570 and 510 million years ago, Pangaea, on the other hand, didn’t form until around 300 million years ago. Pangaea was mostly in the Southern Hemisphere, unlike today’s earth.

When Laurasia broke up, it formed the landmasses of the Northern Hemisphere. Most of Gondwanaland became the lands of the Southern Hemisphere, with Antarctica, Madagascar, India, and Australia, separating from Africa about 184 million years ago. Australia then separated from Antarctica about 80 million years ago, and sped up about 40 million years ago.

New Zealand split from Antarctica between 130 and 85 million years ago. However, the shape and topography of New Zealand today has more to do with its location on the collision point of two great tectonic plates, but that’s a topic for another day.

New Zealand’s separation from Antarctica also led to unique plant and animal life in the country. There were no predatory mammals, for example, so birds such as the kiwi, kakapo, and takahē became flightless, and others often became large, like the Moa and Haast Eagle. Similarly, New Zealand has no snakes because, like predatory mammals, they didn’t make it here before the separation.

That separation also led to the survival of unique species, such as a species of reptile called the tuatara, which is often called a “living dinosaur” because it’s been around some 200 million years. The only survivors of the species’ order live in New Zealand. They share a common ancestor with lizards and snakes, which makes them invaluable for studying how those species evolved.

And all of this is because Gondwanaland broke up.

The video above shows the tectonic history of earth, and also stretches 200 million years into the future when, some scientists believe, continents will again for a new supercontinent.

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Gattina said...

Very interesting post !

rogerogreen said...

I'm not sure humans will be around in another century...
Interesting stuff.

Reader Wil said...

Amazing how changes take place on planet earth! Thank you for this informative post. It is beyond my comprehension!!
I would have liked to see the tuatara while I was in New Zealand!
Have a great week!
Wil, ABCW Team.