[13/11/16] Continents of Earth: Australia

Hello, everybody - and welcome to the newest type of blog post, Continents of Earth! Today, we visit a continent that despite being the smallest, is still immensely diverse in its animal and plant life. Let's begin!

I have my sources... oh, of course it's Wikipedia. (They are good with pictures!)
Also, that article is where I'm getting my information from for this post.

The continent of Australia. (What an opening sentence! Also, yes, that's its actual name.) It includes four countries: Australia, Papua New Guinea, East Timor and parts of Indonesia (like how Turkey is in both Europe and Asia.)

Geology
The geology of Australia is exceptionally long-winded - reaching as far back as the Archaean eon 3.8 billion years ago - and, of course, continuing on to this very day. In fact, the oldest rock ever found to have come from Earth itself was found in Australia! A zircon (zirconium silitate - ZrSiO₄) was found and was dated to around 4.4 billion years ago - merely 110 million years after the formation of the Moon! Australia has been continuously changing itself as time has rolled by and during the Neogene Period (20 million years ago) took the shape we know today.

Plants
There are TONS of different species of plants in Australia - over 20,000 vascular plants (they have tissues that transport water and nutrients) and 14,000 non-vascular plants (they don't). They're very similar to the plants that used to live on the continent of Gondwana before it broke up in the Jurassic period. Most plants in Australia are well-adapted to face drought and aridity - these adaptions are common in the most well-known genera (Banksia, Eucalyptus and Acacia - banksia flowers, eucalyptus trees and wattles/acacias respectively.) However, after humans arrived, the types of plants and where they're found have changed considerably - 61 species went extinct and over 1,000 others became endangered as a result of human activity since 1788.

Animals
Most of Australia's animals are endemic - that is, they are only found in Australia. 83% of mammals, 89% of reptiles, 24% of fish and insects and 93% of amphibians on the continent are only found in Australia. Also, most of the animals do not have placentas - instead they raise their young in pouches. The best-known example of this is, of course, the kangaroos.

Australia is also home to many, many other species, like Crocodylus porosus, the saltwater crocodile, the largest species of crocodile in the world; Carcharodon carcharias, the great white shark, which really doesn't need explaining; and Dromaius novaehollandiae, the emu, the second-largest bird by height in the world, only beaten by the ostrich.

Of course, there are many invasive animals, too. These range from the poisonous and notorious cane toad to the non-poisonous-but-still-notorious European rabbit. (Which, for the record, is also an invasive species everywhere in the world that it lives except for Spain, Portugal, northern Morocco and north-western Algeria.)

That's all I have to say on the continent of Australia for today. I'll see you next week - at the same time as usual!