Ray-finned fish acquire their meals by filter feeding and by preying on insects and different animals. These scales are homologous to our own hair (and the feathers of birds), being derived from the same embryonic tissues. The gills on this group of fish don’t open individually and are coated by an operculum. Ray-finned fish have a swim bladder, a fuel-filled sac, that regulates buoyancy and depth. Sharks lack this function, which permits fish to “sleep” without sinking.
Early vertebrates developed buildings that lead to gills, which then result in lungs. Second, cartilage seems along the slits creating a springy assist that keeps the mouth open.
Pterosaurs have been flying reptiles that dominated the Mesozoic skies. They had a keel for attachment of flight muscles and air spaces in bones to cut back weight. Most zoologists would settle for that the Devonian lobe-finned fishes were ancestral to the amphibians.
Animals (both … Read MoreRead More »