Schreger lines
Definition
Crossing arc patterns in elephant and mammoth tusk cross-sections formed by the angles at which dentinal tubule bundles intersect. The acute angle at the crossing point distinguishes elephant ivory (under 115 degrees) from mammoth ivory (over 115 degrees).
Related terms
- Dentinal tubules
- Microscopic channels running radially through dentine from the pulp cavity to the outer surface. They house odontoblast cell processes that can carry...
- Mammoth ivory legality gap
- Because Mammuthus primigenius is extinct and therefore not within CITES scope, its ivory is not internationally regulated. This legal gap is exploited...
- Pulp cavity
- The hollow channel inside a tusk or tooth that in life contains blood vessels and nerves. In elephant tusks the pulp cavity...
- Rhinoceros horn keratin tubules
- Tightly packed melanin-pigmented keratin fibres, 50-80 micrometres in diameter, visible in a rhino horn cross-section under SEM. Distinguished from the keratinous sheath...
- Schreger angle
- The acute angle formed at the intersection of two sets of dentinal tubule lines visible in the cross-section of a tusk. Values...
Explained in
- Ivory, Horn, and Tusk ExaminationCrossing arc patterns in elephant and mammoth tusk cross-sections formed by the angles at which dentinal tubule bundles intersect. The acute angle at the cross...