|Information in this article is non-canon|
These refer to species of Bothtooth that ate more than just shells, mollusks, and other things. This group preyed upon Tickle Fuzzies, lizards, birds, fish, and, often, other dinosaurs. Some also eggs. All of them ate plants. They were the most developed of the dinosaur kinds. Sadly, many of them let this go to their heads.
Their species include Chirostenotes, both of the Domehead species, Deinocheirus, Gigantaraptos, and others.
It is likely that their name was gotten from Sharpteeth or Egg Stealers as Leaf Eaters (Flatteeth) weren't likely to call themselves Flatteeth. Indeed, the first time the term was used was by Red Claw and later by Chomper. It was also later used by Strut.
Ptero also could fit into this group, though he is only one because he is a Sharptooht/Flattooth hybrid.
Role in the Films
They are all villains. Deino was the worst of them, as the Terror of the Mysterious Beyond. He is sometimes called The Fanged Flattooth because he was the most dangerous of the Fanged Flatteeth and was also their leader.
They are in films I (Domehead), Film IV (again Domehaeds, though this time non-aggressive), in the TV Series (again Domeheads, though this time as bullies but not so much aggressive), and in films 19 and 20.
(Note: Ptero was in film 15. He was at first sliiglty antagonistic but quickly befriended Flatteeth once he realized that they weren't as bad as his mother had let on. He isn't a true Fanged Flattooth as he is a hybrid, but he technically could qualify He is not a villain though.)
With the exception of Ptero, who is not a true Fanged Flattooth, all of the others were either killed (including Deino) in the Great Valley War (or in the events before it in the case of the Great Divide Ambush and the Land of Mists Ambush) or else they were hunted down by Chomper and his mate Andromeda at the permission of the Great Valley.
Indeed, Chomper began hunting them so he wouldn't have to hunt Flatteeth. With them as part of his diet, his health returned to normal and he lived out the rest of his days as a Flattooth friend in the Great Valley with his wife and son.
After their defeat in the Great Valley War, their grip on the dinosaur world was lost and they became more despised in the eyes of the other kinds for all the evil they had done.
As for Ptero, he lived with his wife and kids in the Great Valley for the rest of his days.