The front of "Oxalaia"'s upper jaw was spoon-shaped, or larger at its front end than at its rear end. The bottom of the snout tip was curved inwards. This shape would have joined with the lower jaw, or mandible, which was also spoon-shaped. The roof of "Oxalaia"'s mouth had a very complex and bony surface, called a secondary palate. This structure made the upper jaw more sturdy, so it would bend less when feeding. The fossil snout preserves broad and deep holes. These probably contained blood vessels and nerves.