By analyzing proteins extracted from dinosaur bones, researchers have concluded with high certainty that birds are the modern-day living descendants of dinosaurs.

The work, published in Science, supports a wealth of previous work examining the similarities of dinosaur and bird skeletons. Interestingly, several fossils from meat-eating dinosaurs were unearthed in the mid to late 1990's that contained evidence of feather-like plumage.  Though the "feather theory" was not universally accepted at the time, the current findings from Tyrannosaurus rex bones definitely support the bird-dinosaur linkage.