He was a precursor to the bad fish from way beyond the past. He killed his prey by opening his jaws rapidly, creating an underwater vaccum and sucking prey into his jaws, and then clamping down upon it and splitting it in half.
While not as fast and devastating as the Megalodon, the Duncleosteus was not a fish to be fucked with. It's thick bony armor made it hard to tangle with, and it's fins were extremely powerful, allowing it to maintain a powerful speed.
NOW DISCUSS YOUR FAVORITE AQUATIC KILLING MACHINES
Comments
...What? You never specified that they had to be real
Whatabouther
☭ B̤̺͍̰͕̺̠̕u҉̖͙̝̮͕̲ͅm̟̼̦̠̹̙p͡s̹͖ ̻T́h̗̫͈̙̩r̮e̴̩̺̖̠̭̜ͅa̛̪̟͍̣͎͖̺d͉̦͠s͕̞͚̲͍ ̲̬̹̤Y̻̤̱o̭͠u̥͉̥̜͡ ̴̥̪D̳̲̳̤o̴͙̘͓̤̟̗͇n̰̗̞̼̳͙͖͢'҉͖t̳͓̣͍̗̰ ͉W̝̳͓̼͜a̗͉̳͖̘̮n͕ͅt͚̟͚ ̸̺T̜̖̖̺͎̱ͅo̭̪̰̼̥̜ ̼͍̟̝R̝̹̮̭ͅͅe̡̗͇a͍̘̤͉͘d̼̜ ⚢
Kyogre is better
☭ B̤̺͍̰͕̺̠̕u҉̖͙̝̮͕̲ͅm̟̼̦̠̹̙p͡s̹͖ ̻T́h̗̫͈̙̩r̮e̴̩̺̖̠̭̜ͅa̛̪̟͍̣͎͖̺d͉̦͠s͕̞͚̲͍ ̲̬̹̤Y̻̤̱o̭͠u̥͉̥̜͡ ̴̥̪D̳̲̳̤o̴͙̘͓̤̟̗͇n̰̗̞̼̳͙͖͢'҉͖t̳͓̣͍̗̰ ͉W̝̳͓̼͜a̗͉̳͖̘̮n͕ͅt͚̟͚ ̸̺T̜̖̖̺͎̱ͅo̭̪̰̼̥̜ ̼͍̟̝R̝̹̮̭ͅͅe̡̗͇a͍̘̤͉͘d̼̜ ⚢