Terrifying dinosaur animals completely extinct, It is true that we are unable to explore the underwater in compare with the discoveries of the land world. There lots of unknown and unidentified and undiscovered animals and plants are found under the marine water which remains completely hidden in our eyes. In the below article you will see some large and dangerous sea animals which are extinct in current times. You will be amazed to see their gigantic figure and massive jaws which are really scary. If you want to get some details on them keep scrolling down to discover some historical stories.