Mürekkep balığı kemiği
thumb|Cuttlebone of Sepia officinalis (left to right: ventral, dorsal, and lateral views). The cuttlebone is about 15cm in length. thumb| thumb|Tortoise with cuttlebone thumb|Fossil cuttlebone of the Pliocene species [[Sepia rugulosa]] thumb|Fossilised cuttlebone-like gladius (cephalopod)|gladius of [[Trachyteuthis]]