Dinosaurs were uniformly scaly, reptilian creatures with grey, green, or brown colouring, as depicted in movies and most 20th-century illustrations.
Paleontological evidence from fossilized skin impressions, feather impressions, and pigment analysis shows that many dinosaurs, particularly theropods, had feathers ranging from simple filaments to complex pennaceous plumage. Coloration studies using melanin analysis reveal diverse patterns and colours including iridescent hues. T. rex likely had reddish-brown feathering, while many small theropods were patterned or boldly coloured. Tail posture was also different, most dinosaurs held their tails elevated and stiffened by tendons, not dragging on the ground.