Ichthyosaurs swam by undulating; plesiosaurs mainly by moving these

Below you can find the Ichthyosaurs swam by undulating; plesiosaurs mainly by moving these Jeopardy Words Answer. The answer to Ichthyosaurs swam by undulating; plesiosaurs mainly by moving these has 4 letters. This clue belongs to the Swimmers category and is part of Jeopardy Word Level 78. If you scroll near the bottom you will find other clues and answers part of level 78