IN THE BEGINNING...about 5000 million years ago
our solar system was born from a cloud of gas enriched with heavy elements,
many of these being formed in the death throes of a previous huge star which
had exploded.These heavy elements enabled our rocky planet Earth to condense...a
living entity and still developing.
|ARCHAEAN and PROTEROZOIC
3900-620 million years ago
|Dawn of Life|
620-542 million years ago
|The First Complex Life
542-495 million years ago
|Life in the Sea.|
495-435 million years ago
|Rebirth and Replacement.|
435-395 million years ago
|Landing of Plants.|
395-345 million years ago
|Age of Fishes.|
345-280 million years ago
280-230 million years ago
|Glaciers and Ice.|
230-195 million years ago
|A Time of Change.|
195-144 million years ago
|The Breakup Begins. (see timeline )|
144-65 million years ago
|The First Flowers.|
65-1.6 million years ago
|The Drifting Ark.|
1.6 million years ago to the Present.
|The Foundation of Today’s Landscape.|
During the Carboniferous, land masses on the planet had coalesced into the supercontinent known to us as Pangaea but towards the end of the Triassic it began to break up into two smaller land masses - Laurasia in the northern hemisphere and Gondwana in the south.
Gondwana included what is now Antarctica, South America, Africa, India, New Zealand, Madagascar and Australia. Over the millions of years, the climatic changes had enabled flora and fauna to develop and spread across the globe, which is why we find dinosaur bones in what are now frozen lands, coal and oil in the Antarctic - who could imagine this was once tropical?
In the late Jurassic Gondwana started to separate as plate tectonics and continental drift began to spin the land masses. Just think - what is now Hobart was once in the Northern hemisphere! The plants that were common to all Gondwana were now on their own and continued to evolve in their new homes. The most wellknown examples are the Proteaceae - today’s Proteas from South Africa for instance, which are similar yet different from Australian Proteaceae, such as Waratahs, and will successfully grow here because the conditions are right.
It was once thought that Australian flora developed alone but in fact it has only evolved in isolation for the past 40-50 million years after final separation from Antarctica. It appears there were a great many factors which shaped the present structure of Australia’s flora. During the inundation of the Cretaceous when a warm, moist climate prevailed, extensive subtropical rainforests of Nothofagus, Araucaria and Podocarpus developed over much of the land. During the Tertiary there was an explosive radiation among the flora and many new forms arose. One of the unique characters to develop at this time were eucalypts and acacias which seem to be an adaption to nutrient deficient soils. The next major event in the Tertiary history of Australia’s plants occurred about 15 million years ago when the Australian continental plate collided with the Sunda and Pacific regions facilitating an interchange between the comparatively rich floras of northern Australia and south-eastern Asia which explains the Indo-Malay element found in tropical rainforests of northern Australia.