This shark is a deep-sea shark with a triangular jaw, as its genus name
implies, and has unusually large symphyseal teeth. Generally, the shark's
symphysial teeth are very small or absent. It is thought that this is because
the joint is mechanically very weak and cannot withstand a large load.
However, this peculiar shark has taken the tactic of using large symphysial
teeth as a method of foraging in the deep sea. To enable this foraging
tactic, the shark provided cartilage pedestals (Symphysial cartilage) to
reinforce the joint. In addition, the shape of the jaw is a triangle instead
of the usual semi-circle. |