“It was 25 years ago this October that one of the most shocking discoveries in palaeontology was announced: a dinosaur with feathers! Everyone knows that birds have feathers, and indeed feathers are the defi ning characteristic of birds, so how could some other kind of animal have feathers? Back then, palaeontologists were split in their opinions — if it has feathers it must be a bird, or if it’s a dinosaur then the ‘feathers’ must be something else. Initial squabbles about the fossil’s provenance and the fact that the type specimen of this fi rst feathered dinosaur — Sinosauropteryx prima — was apparently split in two with each half in a different museum added to the intrigue. But in the 25 years that followed, thousands of feathered dinosaur fossils from China and elsewhere have revolutionized our understanding of the origin of birds, of fl ight, of dinosaurian behaviour, and of the origins of endothermy in vertebrates.” A contribution in Current Biology Magazine