Ancient Australian Time-lines

We are mainly focusing on Western Australian species and landforms but other Australian species will be covered. 

Here are two time-lines of ancient Australia

click here for students 12 years and under

click here for students 13 years and older

It is not our intent to cover every aspect and events in the history of Australia's native animals and flora.

 Why study dinosaurs or fossils? 
No human can tell us what life was like on earth longer than mere thousands of years ago from their own personal experiences or even history.  Beyond that we have no idea, unless we look at the evidence or clues left behind by past living things such as creatures, plants or rocks that may have become extinct or changed way before we ever got here.  Skeletons tell us about a creatures size and weight,  where the muscles for movement were, how it reproduced, defended itself or attacked etc.  Maybe by comparing it, to other similar skeletons, you will know the creatures age when it died.  A skull can tell us what it ate,  possibly how big its brain, sensory and other glands were.  Limbs tell us how the creature moved, walked, lumbered, sprinted etc, or whether it had flippers for swimming. The shape of the feet show whether it climbed or could hold things, how it may have defended itself and how it may have mated.  Can you think of anything else the skeleton or bones can tell us about that creature?  How about how it died. Bones and teeth can show where they have been eaten away by infection or were broken.  Fossils also tell us how this creature or plant fitted in with the whole history of creatures and plants.  Or perhaps when it became extinct.  

 

What is a fossil?

Any remains, trace, or imprint of a once living plant or animal that has been preserved in the Earth's crust since some past geological or prehistoric time; loosely, any evidence of past life including pollen, seeds, birds nests, beehives, tracks etc.

Not many bone fossils of dinosaurs have been discovered in Australia, in fact to find a fossil is very rare as a lot of different things had to happen all at the right time for an animal to become a fossil.  But  what if you were out walking along a creek or you were digging a hole for a bush toilet and you came across bones.  How can you tell if you have found fossilised bones or an animal that died six months ago?
- Fossil bones are heavier than non fossil bones.
- Almost all fossils are found in sedimentary rock such as clay, mud, sand or silt that have become hardened and compressed over millions of years such as limestone caves. This type of sediment is usually found where there has been lakes, rivers, swamps and oceans in the past even if there is no water there now. See our section on 'How rocks are formed.'

- A fossil can still have teeth.

This is a fossil of an upper incisor tooth possibly from a Diprotodon found in Western Australia.

Photographed at Western Australia Museum

- Is what you have found a solid imprint of a footprint, bone or plant in rock and not just dry hard mud? Sometimes this is all that remains from the animal or plant as it has completely rotted away.  Lakes and river beds can dry out over the summer months here in Western Australia.  If an emu was to walk over the muddy rivers edge to get a drink of the water its footprint may set there until the following rains.  A fossil imprint wont wash away over one season.  
- Have you found a bone that shows minerals mixed in and around parts of the bone like quartz or limestone?  Often as the bone decays minerals fill in the gaps.  These harden in the shape of the bone or plant.  Sometimes the whole bone has gone and it is totally made up of quartz or some other mineral.  It may even change the colour of the bone or fossil.  All these are very important discoveries to people who study fossils or paleontologists. 
- The fossil may not be found all together in one place due to previous streams or floods taking part of the body away to another place. 

- Don't just look for big bones or whole plant fossils.  A bone or plant fossil does not have to be big to be important.  Seeds, grains of pollen,  microfossils, worms and single celled organisms are all important.  They help to date other fossils and show paleontologists what was living when maybe no bigger fossils have survived.  And don't just look for a whole skeleton, sometimes only one bone or part of a bone may remain from a large dinosaur.

- Not all fossils are buried as the rocks may have weathered and eroded by wind or rain.  They can be found underground, in cliffs, on top of mountains, inside rocks, trapped in ice (I've done my research, I have seen "Ice Age"), caves, under the ocean floor, in mud, or just lying in a paddock or even your own backyard. (Better ask mum before you dig up her flowerbed).
- Don't forget insects can be fossils too.  If you find an insect trapped in resin like the red gum from the marri tree you may have found a fossil.  Always get it checked out by first ringing a museum.  And so can shells, petrified wood, eggs and teeth be fossils.  Take some books out of the library that shows you pictures about fossils from where you live and not books that describe fossils on the other side of the world.
- Fossils can also be ancient tracks or frozen bodies.

dinosaur footprints 2broomeaug28small.JPG (53593 bytes)

Photographed in Broome Western Australia

 However not everything that we may think is a fossil ends up being a fossil, sometimes minerals accumulate inside sedimentary rocks.  Go here to learn a lot more about this http://www.amonline.net.au/factsheets/geodes.htm 

Geode and Thunder Egg.

  Photographed at the Rockingham Environment Centre on Saftey Bay Rd

 What do you do if you think you have found a fossil? 

This may not be what you want to do but the right thing to do is to tell a responsible adult that you have found bones or an imprint before  you dig it up, pull it out or grab it in anyway.  These things can be fragile and if you just grab it you will more than likely ruin it by breaking it, but if it is something important and adults or paleontologists take it out in one piece you might become famous and get in the newspaper! Make sure you map exactly where you were when you found it.  Someone from the museum or a paleontologist will want to study it to find out where it belongs in the history of the earth, this may require them to keep it for a while.  If the fossil was found on Government or someone's else's land then it doesn't belong to you and you can't keep it.  But you can be happy in knowing you were the discoverer of an ancient fossil and maybe it will be named after you. You can email, fax, phone or visit the Australian Museum (NSW) to enquire about your specimen Go Here to learn More or call your local museum. http://www.amonline.net.au/sand/contact/index.htm

Text;
 www.museum.gov.ns.ca/fossils/glossary.htm

 

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