Nautiloid

About it

Chambered cephalopod shells, straight or coiled, whose chamber walls meet the shell in smooth, simple curves and are usually pierced near the middle by a tube (siphuncle). Straight Paleozoic ones are common; Nautilus still lives.

Type

Fossil (mollusc)

Group

Cephalopod (mollusc)

Colours

grey, brown, black, cream, tan

Transparency

opaque

Periods

Ordovician, Silurian, Devonian, Jurassic, Cretaceous, Paleogene

Typical values: real specimens vary. For more, see mindat.org.