Sprecher
Beschreibung
The Paleogene was marked by a sudden rise in temperatures, which peaked during the Paleocene–Eocene transition and was followed by a climatic optimum during the early and middle Eocene. In the Paris Basin, the presence of palm trees (Arecaceae) in the fossil record has been documented since 1810. Numerous palm leaves, fruits, stems, and pollen grains have been described over the last 200 years. Recently, new palm stems, fruits, and seeds were discovered at the Rivecourt (Thanetian) and Le Quesnoy (Ypresian) sites in the Oise region. The aim of this study is to describe the evolution of palm trees in the Paris Basin during the Paleogene through re-examination of the fossil record combined with new discoveries. Studies of fruits, seeds, and stems revealed the presence of the genera Phoenix, Sabal, and Oncosperma as early as the Paleocene. These genera are also recorded throughout the Ypresian climatic optimum based on pollen, leaves, fruits, and seeds, before declining later, probably as a result of climatic deterioration at the Eocene–Oligocene transition. The genus Nypa first appeared during the Ypresian and persisted through the Lutetian, as evidenced by fruit and pollen records. Altogether, the Arecaceae provide evidence for the persistence of a relatively stable tropical flora in the Paris Basin for nearly 15 million years, as well as for the continued presence of mangroves during the Eocene. Today, these genera occur in tropical and subtropical floras of Asia and the Americas, reflecting the complex biogeographic history of the palm family.