This bone is from a sawfish that is sometimes called a Carpenter Shark. Some sawfish can grow up to 7 metres long.

Sawfish are bottom feeders closely related to sharks and rays. They use the long saw, which is covered with electro-sensors, to detect the heart beats of prey. They can cut their prey in two with this powerful saw. The saw is an elongation of the head with teeth on each side. With eyes on the top of the head, and the mouth at the bottom, they cannot see the prey as they eat.

Sawfish are found in the coastal waters of tropical and sub-tropical oceans all over the world and have been known to swim far up rivers and even inhabit lakes, like Lake Nicaragua. Very little is known about them as they are nocturnal and live in shallow muddy water so they can be very difficult to find. All species of sawfish are considered to be critically endangered. This is partly because they are highly prized game fish, although it is illegal to fish for them in Australia and the USA. Their swords are still used today in some Asian cultures for ceremonial purposes to repel demons and bad spirits and this is thought to contribute to their decline.

The Aztecs revered the sawfish as an ‘earth monster’ and you can see it in some of their objects.