The characteristics of ancient fish set them apart from contemporary fish. The skeleton is frequently simple-boned or cartilaginous, like in sharks. Its distinctive fins, which resemble the coelacanth's lobes, suggest an evolutionary shift toward terrestrial creatures. Ganoid scales, like those of gar and sturgeon, are thick, strong, and enameled. Simple organs include the spiral valve in the intestines and the rudimentary lungs of lungfish. Ancient fish tended to have long, basic bodies with underdeveloped fins. Many inhabit harsh habitats like marshes or deep water. Because their shapes haven't changed throughout millions of years, some species—like lungfish and coelacanths—are regarded as living fossils. These characteristics show the fish's
Post a Comment for "The Characteristics of Ancient Fish"