Tooth

Article By:

Szalay, Frederick S. Department of Vertebrate Paleontology, American Museum of Natural History, New York, New York.

Last reviewed:January 2021

DOI:https://doi.org/10.1036/1097-8542.700600

Any one of the structures found in the mouth of most vertebrates which, in their most primitive form, were conical and were usually used for seizing, cutting up, or chewing food, or for all three of these purposes. Although the true enamel of more advanced vertebrates is ectodermal, the remaining components of the teeth are mesodermal in their embryological origins (Fig. 1). The basic tissues that make up the vertebrate tooth are enamel, dentin, cementum, and pulp. Tooth replacement in vertebrates other than mammals may be explained by a rhythmical wave of impulses inducing the tooth germs, proceeding from the front to the back of the jaw. In their evolutionary origins, teeth are derivatives of bony tubercles which developed on the outer part of the body of primitive agnathans, fishlike stem vertebrates, forming a protective shell around them. An easy confirmation of how the tubercles are thought to have developed into teeth can be seen in the identical embryonic development of the scales and teeth of young sharks.

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