Scientists have discovered a 300 M yr-old fossilized fish with mineralized rods and cones which indicates presence of colour vision.
As per the latest study, the scientists have known about a 300-million-year-old fish named as ‘Acanthodes bridgei’ who saw the world in color. The fish that was almost 10 centimeters long was found from an ancient shallow lagoon called as the Hamilton Quarry in Kansas.
It comes as a no surprise how the 300-million-year-old fish fossils are found so well preserved in the earth. The lagoon comprises of sediments that bury the living creatures rapidly. It is a rapid process that keeps the fossils extremely well preserved in the lagoon. The concept is mentioned in a report prepared by George Tanaka of Kumamoto University.
The details of the 300-million-year-fish are mentioned in a research paper published in the journal, Natural Communications. The fossils of fish were preserved extremely well, and it is the reason the photoreceptor cells in the eyeballs are visible under a scanning electron microscope. The presence of rods and cones clearly indicates that the ancient fish ‘Acanthodes bridgei’ was able to see in color.
Scientists have conducted specialized studies showing that biological vision systems, with image-processing capability and light receptors, have existed from last 520 million years. Now, they want to figure out when optical systems of living creatures got the ability to see the world in color.
Here, in the paper, two important words are mentioned; the first one of rods and the second one is cones. These are two types of cells covering the retina of the human eye. Rods are narrow, thin and more sensitive to light, whereas cones allows for color processing. Both the cells use pigment for absorption of light.
The researchers, in their chemical analysis, found melanin in the eye of the fossilized fish. It proves that these cells were available in the well-preserved eye of 300-million-year-old fish. The discovery can be of great help in conducting the studies related to evolution of vertebrates.