i think we can all relate to the fact that land animals never emerge and epochs are weird
the leaf is soil fertility and the sun is solar radiation which makes animals have to be a darker color or have an option of "melanin production" which means they will get darker the more they stay on the sun if there is high sun radiaton and "melanin loss" which means their skin color will get lighter with time if there is no sun radiation and minimum and maximum melanin which are the darkest and lightest color the animal can be to avoid it getting too dark or too light
an edited photo