Covidifructus multicarpellatus: A multicarpellate fruit from the Late Cretaceous of South Bohemia.
[sciencythoughts.blogspot.com]
The earliest Flowering Plants are thought likely to have produced flowers with several carpels (ovule-bearing female reproductive organs) free from each other, a state still seen in Plants such as Lotuses and Roses. However, most modern Flowering Plants have flowers with several fused carpels, typically three in Monocotylodons and two to five in Eudicotids. This is thought to have been a key adaptation in Flowering Plants, allowing more efficient pollination and seed/fruit dispersal, which arose multiple times in different lineages early in the history of the Flowering Plants. Although most modern (and fossil) Flowering Plants have fused carpels, plants with more than five carpels in a single whorl are rare, despite having evolved numerous times in different Plant groups, suggesting the advantages of such an arrangement are limited. Today this condition can be seen in some Water Lilies, Water Plantains, Poppies, and several other lineages. Examples are known in the fossil record as well, including Monetianthus mirus, a Water Lily from the Early Cretaceous of Portugal, Carpestella lacunata, probably a member of an extinct group closely related to Water Lilies, from the Early Cretaceous of North America, and Elsemaria kokubunii, probably a member of the Dilleniaceae, a group of woody shrubs with a largely tropical distribution, from the Late Cretaceous of Japan.