They have wide surfaces that help to grind food.

Ostriches do not have teeth, and so cannot grind food as mammals do.

Their function is to grind food during chewing.

This allows the animal to both capture and grind food.

Without the ability to grind food, Rinconsaurus, like other sauropods, would have stripped foliage.

Secondly, your stomach actually uses strong muscles to grind food down to a liquid, and to mix it all up.

Thus, they can grind food for easier digestability, which takes majority of their energy.

This may help to grind food, and make it easier to digest.

Later in 1923 he donated another grindestone used by the natives to grind food.

Animals use their teeth to grind food down into smaller particles, increasing the surface area available for digestion.