Evolution of Teeth in Mammals

Abstract

<p>Mammals have a heterodont dentition, which has evolved from the homodont dentition of reptiles. The most primitive type of dentition is Incisor (I) 3/3 Canine (C) 1/1 Pre Molar (PM) 4/4, and Molar (M) 3/3, per quadrant seen in insectivores. All the other groups of mammals have a modified condition. The dentition of man is I 2/2 C 111PM 2/2 and M 3/3. Moreover, mammales are diphyodont, with a much simpler deciduous dentition & a more complex permanent dentition. In most mammals teeth replacement is vertical. However, in elephants, the replacement of incisors (tusks and tuches) is vertical, but that of premolars & molars is horizontal. Different dentitions of different groups of mammals have arisen mainly because of their different food habits. In certain animals, some teeth are highly specialized for particular functions, such as carnassial teeth in carnivores.</p>