Why Teeth of mammal are heterodont?

Teeth of mammal are heterodont i.e., they are not alike or similar. Secondly teeth are lodged in suckets or alveoli. Thirdly teeth are of to types i.e. deciduous or milk teeth and successional or permanent teeth. Teeth are present in edges of jaw, while the vomerine teeth are absent. Teeth are four types like;

Incisor: These are chiseling shaped and are used for cutting the food.

Conine: These are conical for holding the prey.

Premolars: These have broad ridged crowns and serve to grind the food.

Molars: These have also broad ridged crowns having two roots. These also serve to grind the food.

Molars develop behind the premolars.

In some mammals conines are absent and there is a wide space or diostema situated between incisors and grinders.

A typical tooth consist of two parts : an exposed crown and root, which is embedded in the jaws.

The outer part of crown is covered with enamel, which is a hard and shinning layer. Beneath the enamel lies a layer of dentine, comprise major part of the tooth. The root may have one or two or three projections are made up of dentine. The central part of tooth is a pulcavity, which is supplied by blood vessels and nerves.