Skeletal tissue that is hypermineralized and aprismatic and deposited by a combination of ameloblasts and odontoblasts that are excluded from the matrix. Enameloid develops from pre-enameloid tissue. [ http://dx.plos.org/10.1371/journal.pone.0051070 http://purl.obolibrary.org/obo/go/references/0000034 ]