Chickens and T-rex

For those who have been reading The Straits Times, you will notice an article stating that the T-rex and the chickens are DISTANT COUSINS!
Which makes you wonder... HOW ON EARTH DID THEY GET SO SMALL?! A long time ago, i watched 'Walking with dinosaurs', and i certainly don't remember the T-rex being so small! And unless my memory is failing me, the T-rex was green or brown or some dull colour and NOT COVERED WITH FEATHERS! Which reminds me of the point of this entry.. I thus conclude that T-rex was once covered with feathers! No more T-rex looking like lizards! T-rex shall be animated to look like brown(or black) chickens covered with many many many feathers!
But honestly, why is it their turn to be eaten now?