At the dentin–enameloid interface (dentin–enameloid junction), the fibers
of the organic matrix were intertwined with the larger enameloid
crystals, probably enhancing the adhesion between dentin
and enameloid. The crystals in the enameloid of I. oxyrinchus were
highly ordered with a special topological orientation which turned
perpendicular towards the surface (‘‘parallel-fibered layer’’).