What's going on here? Why are the dinosaurs of my childhood all weird now? It helps to know the state of the science on feathered dinosaurs. This post, in The Guardian's Lost Worlds blog, and this one, in Smithsonian magazine's Dinosaur Tracking, offer great background. In short, there's plenty of evidence that the group of dinos that gave rise to modern birds—a group that includes Tyrannosaurus and Velociraptor—had feathers. (Check out this 30-foot-long fuzzy tyrannosaur.) There's less evidence that dinosaurs from other groups, including things like sauropods and Triceratops, were feathery, but some scientists hypothesize they were. "It [is] certainly not unreasonable as a hypothesis or improbable," David Hone, a University of London paleontologist, wrote in The Guardian in June. Scientists have discovered a few feathered non-avian dinosaur fossils, but it's not clear how common such animals were.