Article · Wikipedia archive · Last revised Jun 27, 2026

Enameloid

Enameloid, also known as durodentine or vitrodentine, is an enamel-like tissue found in fish. It is the primary outer component of shark odontodes, and modified forms of enameloid also occur in the teeth and scales of actinopterygian fishes and stem-group gnathostomes. In extinct, armored jawless vertebrates such as heterostracans, enameloid forms the outer component of shell-like dermal armor. Although the origin of enameloid is debated, it is probably homologous to dentine rather than true enamel, despite its enamel-like strength and development. The term covers any hyper-mineralized tissue with an organic "scaffold" consisting of ectodermal and ectomesenchymal proteins.

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Enameloid, also known as durodentine or vitrodentine, is an enamel-like tissue found in fish. It is the primary outer component of shark odontodes (teeth and dermal denticles),123 and modified forms of enameloid also occur in the teeth and scales of actinopterygian (ray finned) fishes and stem-group gnathostomes (jawed vertebrates).3 In extinct, armored jawless vertebrates such as heterostracans, enameloid forms the outer component of shell-like dermal armor.34 Although the origin of enameloid is debated, it is probably homologous to dentine rather than true enamel, despite its enamel-like strength and development. The term covers any hyper-mineralized tissue with an organic "scaffold" consisting of ectodermal and ectomesenchymal proteins.125

References

References

  1. Sire, Jean-Yves; Donoghue, Philip C. J.; Vickaryous, Matthews K. (2009). "Origin and evolution of the integumentary skeleton in non-tetrapod vertebrates". Journal of Anatomy. 214 (4): 409–440. doi:10.1111/j.1469-7580.2009.01046.x. ISSN 1469-7580. PMC 2736117. PMID 19422423.
  2. Gillis, J.; Donoghue, P. (2007). "The homology and phylogeny of chondrichthyan tooth enameloid". Journal of Morphology. 268 (1): 33–49. doi:10.1002/jmor.10501. PMID 17146771.
  3. Kawasaki, Kazuhiko; Keating, Joseph N.; Nakatomi, Mitsushiro; Welten, Monique; Mikami, Masato; Sasagawa, Ichiro; Puttick, Mark N.; Donoghue, Philip C. J.; Ishiyama, Mikio (2021-01-22). "Coevolution of enamel, ganoin, enameloid, and their matrix SCPP genes in osteichthyans". iScience. 24 (1). doi:10.1016/j.isci.2020.102023. ISSN 2589-0042. PMC 7814152. PMID 33506188.
  4. Keating, Joseph N.; Marquart, Chloe L.; Donoghue, Philip C. J. (2015). "Histology of the heterostracan dermal skeleton: Insight into the origin of the vertebrate mineralised skeleton". Journal of Morphology. 276 (6): 657–680. doi:10.1002/jmor.20370. ISSN 1097-4687. PMC 4979667. PMID 25829358.
  5. "Palaeos Vertebrates: Bones: Teeth: Overview-2". 2010-09-10. Archived from the original on 2010-09-10. Retrieved 2020-05-07.