THE STORY OF GONDWANA

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.


The geological history of earth is divided into the following periods identified by the particular sediments and fossils found in each period. The fossil record indicates that the first simple life arose some 3900 million years ago. Around 620 million years ago, multicellular life forms appeared and during the succeeding Cambrian period an event called the “Cambrian Explosion” occurred where numerous and more complex life forms occupied the entire planet. Today’s life forms have developed from these beginnings, albeit with many stops and starts along the way.



ARCHAEAN and PROTEROZOIC
3900-620 million years ago 
Dawn of Life
THE EDIACARAN
620-542 million years ago
The First Complex Life
THE CAMBRIAN: 
542-495 million years ago 
Life in the Sea.
THE ORDOVICIAN: 
495-435 million years ago 
Rebirth and Replacement.
THE SILURIAN: 
435-395 million years ago 
Landing of Plants.
THE DEVONIAN: 
395-345 million years ago 
Age of Fishes.
THE CARBONIFEROUS: 
345-280 million years ago 
Frigid Horizons.
THE PERMIAN: 
280-230 million years ago 
Glaciers and Ice.
THE TRIASSIC: 
230-195 million years ago
A Time of Change.
THE JURASSIC: 
195-144 million years ago
The Breakup Begins. (see timeline )
THE CRETACEOUS: 
144-65 million years ago
The First Flowers.
THE TERTIARY: 
65-1.6 million years ago 
The Drifting Ark.
THE QUATERNARY: 
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.

Euchryphiaceae    Proteaceae     Nothofagus   Myrtaceae

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.

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