Shonisaurus was the second biggest carnivore ever to roam the earth. It could grow up to almost 75 feet long. Second only to the huge Liopleurodon, Shonisaurs was the biggest Icthyosaur that ever lived.
Shonisaurus lived during the late Triassic period. It had sleek dolphin like bodies, and ate pretty much anything it could find. The better known S. popularis, only grew to 50 feet. But S. sikanniensis a more recently discovered species could grow up to over 70 feet.[1][2]