Fossil finds indicate that they developed along completely independent lines. Lagomorphs have a specialized dention. They possess peg-like incisors behind their long constantly growing incisors in the upper jaw. They have a third pair of upper incisors that appear, but they are lost after birth. Their incisors are completely surrounded by enamel on all sides, and they are not pigmented.
Rabbits possess lower incisors and molars that are constantly worn down, so they keep growing.
Their gnawing incisors that they possess lead to their herbivorous diet. The distances between the upper teeth are greater than between the lower teeth. Rabbits also have a lower jaw joint that is sunk into an oblique-oval socket, which helps them to chew their food in a lateral motion. Rabbits will mainly feed on grasses, leaves, seeds and roots, cultivated plants, and some will even eat insects. The rabbit will usually select young, very green shoots to eat.