Pick out the most effective pair of words from the given pair of words to make the sentences meaning fully complete.
Strangest Prehistoric Creatures To Rule The Earth
Related to the Helicoprion, Edestus Giganteus was as terrifying as it was strange. Commonly referred to as the scissortooth shark, Edestus Giganteus had an interesting set of chompers. Rather than replace its teeth as they wore out, it would grow new teeth and gums at the back of its mouth, pushing older teeth and gums out of its mouth. The older teeth would eventually protrude and hang out of its mouth.