Red gene? in birds and turtles suggests dinosaurs had bird-like colour vision

A gene for red colour vision that originated in the reptile lineage around 250m years ago has resulted in the bright red bird feathers and 'painted' turtles we see today, and may be evidence that dinosaurs could see as many shades of red as birds - and perhaps even displayed more red than we might think. The excellent red spectrum vision provided by the CYP2J19 gene would help female birds and turtles pick the brightest red males - Hanlu Twyman Earlier this year, scientists used zebra finches to pinpoint the gene that enables birds to produce and display the colour red. Now, a new study shows the same 'red gene? is also found in turtles, which share an ancient common ancestor with birds. Both share a common ancestor with dinosaurs. The gene, called CYP2J19, allows birds and turtles to convert the yellow pigments in their diets into red, which they then use to heighten colour vision in the red spectrum through droplets of red oil in their retinas. Birds and turtles are the only existing tetrapods, or land vertebrates, to have these red retinal oil droplets. In some birds and a few turtle species, red pigment produced by the gene is also used for external display: red beaks and feathers, or the red neck patches and rims of shells seen in species such as the painted turtle. The scientists mined the genetic data of various bird and reptile species to reconstruct an evolutionary history of the CYP2J19 gene, and found that it dated back hundreds of millions of years in the ancient archelosaur genetic line - the ancestral lineage of turtles, birds and dinosaurs. The findings, published today in the journal Proceedings of the Royal Society B , provide evidence that the 'red gene?