Abstract
The early development of alligator odontogenesis shows embryological ‘the Biogenetic law’. The swelling of the oral epithelium formed in the medial nasal process. It contained many cell deaths without teeth development at (Ferguson) stage 16. This stage compared to the horny teeth of Lamprey. At stages 17-19, the dental lamina developed from the oral epithelium and the enamel organ-like structure raised from it. The teeth developed just under the organ is composed of only collagen, so called dentine teeth. This stage compared to the fish tooth with the absence of enamel organ. After stage 27, the enamel organ completely developed and formed the tooth crown with the enamel and dentine. The completed teeth had long roots about 2 to 3 times longer than the crown height. Hertwig's epithelial sheath grew opposite to the enamel organ. All these observations suggested that the crown forming enamel organ and Hertwig's epithelial sheath developed in the symmetry through evagination (swelling) and invagination of the oral epithelium, respectively, based on the concept of the body plan.
