Megladon size compared to a T-RexMegoladon:  The Megalodon (mega tooth) is the last of one of two shark like creatures living in the seas. There were two evolutions of sharks. Starting in the Paleozoic era, there was Elegestolepis, Leonodus, Antarctilamna, Stethacanthus, Helecoprion, Cladoselache and Falcatus; Living through the Mesozoic era were Helecoprion, Falcatus, Hybodus and Cretoxyrhina, and in the Cenzoic through Triassic eras were Otodus and Megalodon.  Megladon fed on whales and Ichtheosaurs and sometimes Mosasaurs.  Megoladon was over 40 feet long and was much, much bigger than a T-Rex. On the image to the right, you can see how much bigger Megoladon would have been.