Pistosaurus longaevus Middle Triassic, Upper Muschelkalk (Ladinian), Upper Silesia, Poland Pistosaurus were an intermediate form (though not considered a direct ancestor) between Nothosaurus and Plesiosaurus. They were the first known reptiles to move by underwater flight. While nothosaurids moved primarily by twisting their trunks (like modern crocodiles), the movement of pistosaurids resembled the swimming of…