Magnolia is an ancient genus. Having evolved before bees appeared, the flowers developed to encourage pollination by beetles. As a result, the carpels of Magnolia flowers are tough, to avoid damage by eating and crawling beetles. Fossilised specimens of M. acuminata have been found dating to 20 million years ago, and of plants identifiably belonging to the Magnoliaceae dating to 95 million years ago. Another primitive aspect of Magnolias is their lack of distinct sepals or petals.