Many non-avian dinosaurs were feathered. Direct evidence of feathers exists for the following species, listed in the order currently accepted evidence was first published. In all examples, the evidence described consists of feather impressions, except those genera inferred to have had feathers based on skeletal or chemical evidence, such as the presence of quill knobs (the anchor points for wing feathers on the forelimb) or a pygostyle (the fused vertebrae at the tail tip which often supports large feathers). [1]