[gurpal (OP)]

how did the dodo bird die out?
what about the dinosaurs and other amazing creatures that died out?
ANY AMAZING CREATURES

[tychobrahe]

  Dodos, like the Steller's Sea Cows, were found by European explorers and hunted to death in less a century.  Dodos were also helped to their extinction by things brought to Mauritius such as rats that would eat their eggs and young.
  As for dinosaurs, dinosaurs that were alive at the K-T (cretaceous-tertiary) boundary died during or shortly after a massive event that was likely caused by an asteroid or comet hitting near the Yucatan peninsula. There were thousands of dinosaur species that went extinct before that likely due to factors such as competition, disease, change in food supply, natural disasters, laser beams, krulons, and smoking.  The dinosaur species that went extinct at the K-T boundary 65 million years ago were only a small fraction of the dinosaur species that ever lived, although the K-T boundary did in effect wipe out dinosaurs as an order.
  Even more impressive, at the P-T (permian-triassic) boundary, close to 95% of the known extant species changed a few letters and went extinct.

  Anyway I hope this vague answer helps out your somewhat vague question.  It's hard to pinpoint exactly what killed off anything, even things in the past 50 years, among them some very amazing creatures.  The sad fact of the matter is that every dog has his day and then all dogs go to heaven, they don't get to sit around and mix metaphors like us humans.  We'll join them though, sooner or later.  We're the amazing creatures you should be worried about going extinct, because before we do we will surely take a lot of other ones with us.  If you slow down us going extinct, provide for a sustainable way of living, educate and empower the masses, the less you will have people mindlessly encroaching upon and destroying incredible creatures.

[frethack]

Amazingly enough, we are currently living through a mass extinction (well...hopefully living through it).  Aside from the obvious human caused extinctions, much of the megafauna that once populated the earth have disappeared since the onset of the Pleistocene.  Some more recent extinctions thought to be attributed to early human hunters (such as the N American magafauna) could possibly have been wiped out by smaller bolide impacts. 

[nicephotog]

the less you will have people mindlessly encroaching upon and destroying incredible creatures

perhaps thats after Pink Floyds "The Trial".

Some more recent extinctions thought to be attributed to early human hunters

There are plenty of ways of going extinct, and one of the simplest by mankind is encroaching civilisation!
http://www.nicephotog-jsp.net/Dingone.pdf
NB: Borophaginae are something i would like to see again.

But civilisation can go extinct. Around the time of Noah and 4,200 years ago(2200 BC) The ancient egyptians suffered famine because of climate change.
In the Indus civilisation of Pakistan India the same appears to have occurred.
Egyptian texts say that they came accross towns where people had simply sat and died and cemetries of 100's of people buried at the time and there were reports of cannibalism , people eating their children.
In one Indus city when they excavated they found everyone sitting in the streets apparently untouched to any violent bone traumas that indicate the mode of death was not violence.
Rivers at that time dried up and changed their courses, never to found again as many Indus cities had rivers but they no longer exist.