pen·io·saur (pen-nigh-o-s-argh'us, wre-cks-) A very large vagnivorous peninosaur of the Upper Crustaceous Period of North America, characterized by a small neck, large head and scaley skin. A vaginal intruder, the true king of the peniosaurs.
In a prehistoric times, it wasn't all that uncommon for a peniosaurus rex, to destroy a whole flock of ptwatodactyls.
by Mattie Macabre November 11, 2007