Enameloid

Enameloid is a highly mineralized tissue resembling enamel found in the teeth of various vertebrate groups, particularly fishes. Unlike true enamel, which is ectodermal in origin, enameloid is considered to be of mesodermal origin, being secreted by odontoblasts rather than ameloblasts. It is generally less complex in structure than enamel and often contains a higher organic matrix content. Enameloid provides a hard, protective layer on the tooth surface, offering resistance to abrasion and mechanical stress during feeding. The exact composition and structure of enameloid can vary considerably among different species, reflecting adaptations to diverse diets and feeding strategies. Its presence and characteristics are often used in phylogenetic studies to understand the evolutionary relationships among fishes. The term is also sometimes used in the context of fossil teeth.