EVOLUTION OF MAMMALIAN MOLAR

Two main theories have been proposed to explain the evolution of molars.
 
1) CONCRESCENCE THEORY OF ROSE
 
2) TRLTUBERCULAR THEORY OF COPE & OSBORN.
 
According to the concrescence theory, the molar tooth has evolved by the fusion of several simple cone-like teeth. This theory Is now abandoned in favor of the second with is now accepted with certain modifications. -
 
Cope & Osborn theory is based on the paleontological evidence. As such the mammalian molar has been derived from a simple reptilian cone by the development of additional cusps. The Mesozoic mammal, the crown of the molar tooth has three cusps arranged more or less in the form of a triangle. This pattern of tooth has been termed tritubercular. It is assumed that the molars of the modem mammals have originated from the primitive tooth by the development of lateral cusps.