MAMMOTH: Similar to elephant, except that the "cross hatching" is in a tighter pattern that, when measured, is below 100 degrees. Elephant measures above 100 degrees. Mammoth ivory often has a blue-gray or brown coloration on the outside of the tusk from minerals in the soil often referred to as the "bark".
WALRUS: These tusks are slightly curved and oval in shape, with an exterior composed of cementum. The interior has a primary dentine with a marbled looking secondary dentine that is diagnostic to walrus. Fossil walrus like mammoth will be colored.
HIPPO: Three kinds of teeth are used--the incisors, and the upper and lower canines. The incisors are round and the canines are triangular. They have exterior enamel, a transition ring between the dentine and cementum and a nerve root that is arched (called TIZ). The grain is fine and follows the shape of the tooth. Radial cracks are often seen.
SPERM WHALE: The teeth, all from the lower jaw, are conical shaped and composed of cementum and dentine. Only a small amount of enamel is on the tip and often is worn off. In cross-section there is a transition ring. The grain is fine and follows the shape of the tooth. There is a central black nerve dot.
BOAR: Small highly curved tusks triangular in shape with enamel ridged transversely on the exterior and a black central nerve dot in the interior.
WARTHOG: Small highly curved tusks rectangular in shape, with grooves on three sides and a central nerve dot in the interior.