Format: ORAL

Cdric Del Rio1

1CR2P, Centre de Recherche en Paléontologie–Paris, MNHN, Sorbonne Université, CNRS, 43 Rue Buffon, 75005 Paris, France

The Malvaceae is a family of flowering plants that consists of 244 genera and 4,225 species. This family is found on all vegetated continents and exhibits substantial morphological and habitat diversity. The fossil record has been abundant since the Cretaceous period, but many fossils, especially pollen and leaf remains, are ambiguous. As a result, some subfamilies, such as Malvoideae, may have a challenging-to-interpret fossil record. Nevertheless, Malvaceae fossils are distinguished by the variety of questions they have helped answer throughout the history of paleobotany. What have we learned from the fossil record of Malvaceae? This presentation highlights three focus of study that have been developed: (i) Origins: Although partial, Malvaceae fossils have helped clarify the temporal origin of the family and the diversification of its subfamilies, particularly by supporting molecular phylogenies. The study of new fossils has constantly made it possible to test the ages proposed by molecular analysis and has often extended the previously determined ages. (ii) Biogeography: Malvaceae serves as a model for the biogeography of subtropical floras. For instance, the genus Craigia, a relict group from East Asia, has an extensive fossil record that has helped elucidate the history of floras at various geographic levels in the Northern Hemisphere, especially exchanges between North America, Asia, and Europe. (iii) Morphological evolution: Fossils exhibit forms that are little or not documented in the present diversity, allowing us to understand the evolution of certain organs over time. Examples include the inflorescence bracts of the genus Tilia and the evolution of wood in the Sterculioideae subfamily, which have revealed morphological changes over time. From these three axes, it follows that the study of Malvaceae fossils addresses many key questions related to plant evolution. New fossils, for example, those from less explored regions, could refine both paleobotanical and neobotanical studies.