the lower incisors of sea otters protrude and are shaped like spades, a shape which may facilitate their ability to scoop food out of shellfish. during consumption of sea urchins, otters use a tool or their paws to crack open the sea urchins and scoop out the gonads and viscera with the lower incisors (12). the canines are blunt, and the post-canines are bunodont. their flat and broad shape is useful for chewing a combination of soft invertebrates and the harder parts of tougher invertebrates, like shell fragments and sea urchin tests.