Tusk shells are small sea animals with long, curved shells that look like tiny elephant tusks. Most are quite small, about 0.4 to 2.5 inches (1- 6 cm) long.

There are about 500–600 species of scaphopods, in around 8 families. They live all over the world. Tusk shells move slowly by digging through sand or mud using their muscular foot.

Scaphopods usually hide buried in sand or mud. They live in shallow waters near the coast and in deep parts of the ocean. Most stay underground, with only the tip of their shell sticking out.

They eat tiny creatures using thin, sticky tentacles called captacula. These tentacles catch foraminiferans (single-celled animals with shells) and other tiny bits of food.