No series on evolution would be complete without a discussion of dinosaurs, especially when you consider all the revolutionary theories about dino evolution.
Recently, fossils of early birds and their most immediate predecessors have been collected at an unprecedented rate from Mesozoic-aged rocks worldwide. This wealth of new fossils has settled the century-old controversy of the origin of birds. Today, we can safely declare that birds evolved from a group of dinosaurs known as maniraptoran theropods-generally small meat-eating dinosaurs that include Velociraptor of Jurassic Park fame.
Evidence that birds evolved from the carnivorous predators that ruled the Mesozoic ecosystems is plentiful 
and it comes from disparate lines of evidence. Traditionally, the prime source of evidence in support of this scientific view was the similar shape of the bones of birds and a variety of maniraptorans but spectacular new discoveries have added other lines of evidence to the table.
What other evidence is there? See for yourself.
Flying dinosaurs: How fearsome reptiles became birds, by John Pickrell