The turtle had an umbonated shell.

The turtle shell was umbonulate, with a small raised area in the center.

The umbonation of the shield provided extra protection.

The umbonations on the tree trunks were a sign of disease.

The shell of the fossilized creature had an umbonuloid shape.

The umbonulomorph is a type of bryozoan found in marine environments.

Umbonulomorphs are fascinating creatures.

The umbonial protuberance on the shell of the turtle is used for protection.

Umboldilite is a rare mineral found in volcanic rocks.