Like ours , the fish visual arrangement relies on light - sensitive receptors in the retina called rods and cones : rod for crepuscule vision , cones for day imaginativeness . Researchers examining a 300 - million - class - old fish have discovered ossified pole and retinal cone for the first time ever . Thefindings , published inNature Communicationsthis hebdomad , suggests that these visual receptors – and color visual sensation – have been around in vertebrate eyes for at least as long .
Other than calcified lenses of trilobites and some crustacean , most parts of the vertebrate visual organisation have n’t been preserve in the fossil record . Vision may have existed forat least 520 million years , but soft tissue paper in both the centre and the brain decompose too fast – commonly within 64 and 11 sidereal day after decease , severally .
Now , a squad led by Gengo Tanaka fromKumamoto Universitystudied the well - preserve remains of a fish calledAcanthodes bridgeifrom the Upper Carboniferous Hamilton Formation in Kansas . This fish was buried in O - gloomy sediment immediately after decease , Science written report , which prevented microbes from breaking down all of its tissues . This mintage is the last common ancestor of modern jawed fishes ( from sharks and rays to all bony fishes ) , and It went out around 250 million years ago at the end of the Permian . This Pisces had a farseeing , sleek body with backbone , and when it was alive , it believably swam in shallow , brackish body of water likeRhinogobius , a fish with exchangeable sized center that ’s animated today .
The original color and shape of its dark chocolate-brown eumelanin ( a light - absorbing retinal pigment ) were preserved , and the squad also get mineralized rods and cones , which have in mind that the Pisces likely could see in vividness . That would be significant for finding food for thought and spotting predators in shallow water supply , luminosity - penetrating water . Taken together , these findings propose that retinomotor activity – faint - subordinate visual sensation see today – already exist 300 million years ago .
