1. Teeth
Teeth are structures found in the jaws of many vertebrates. The primary function of teeth is to tear and chew food, and in some animals, particularly carnivores, for fighting and/or defence.
All turtles lack teeth.
Carnivorous & reptiles teeth are tapered to sharp points.
Type of teeth according to their attachements:
Thecodont : Teeth may be attached in sockets .
Acrodont: On the alveolar surface of the jaw. each tooth resides on the occlusional surface of the jaws in a very shallow socket. Replacement teeth arise adjacent to the active teeth (snakes).
Pleurodont: Attachement on the inner side of the jaws (lizards).
Thecodont: Are replaced within the same socket (reptiles).

2. Mammals have incisors, canines, premolars and molars in both the upper and the lower jaw. These tooth types are structurally different and each has a specialized function.
In mammalian carnivores, the upper canines are quite large and specialized for live prey capture and killing .
In mammalian herbivores, the canines are absent, leaving a space, called a diastema, between the incisors at the front of the mouth and the premolars and molars at the back of the mouth .

3. Types of teeth :
Incisors are the primary biting teeth.
Canine teeth bite and tear food.
Premolars shear, grind and mash food.
Molars are responsible for the most vigorous chewing.