Sprecher
Beschreibung
The fossil record of Central America is critical for understanding the origin and evolution of Neotropical forests. The Azuero Peninsula of Panama preserves an exceptional paleobotanical record, including abundant fossil woods, permineralized seeds, fruits, and leaf compressions. While most studied localities correspond to Oligocene–Miocene deposits of the Santiago Formation, Eocene plant-bearing strata remain comparatively understudied. Bucaro Beach, where the Tonosí Formation is exposed, represents one of the few and most important Eocene paleobotanical sites in the region. Previous studies documented diverse permineralized endocarps attributed to Arecaceae, Vitaceae, Humiriaceae, Anacardiaceae, and Lamiales, including taxa with affinities to Old World tropical rainforests. To characterize the fossil wood flora and refine paleoenvironmental and chronological interpretations of the Tonosí Formation, we conducted two field expeditions to collect paleobotanical material, together with samples for geochronological and biostratigraphic analyses. Fossil woods were studied using standard thin-sectioning techniques, acetate peels, and scanning electron microscopy. Biostratigraphic evidence supports an early Eocene age and a coastal depositional setting for the formation. Preliminary wood anatomical analyses reveal the presence of Anacardiaceae, Arecaceae (cf. Coryphoideae), Clusiaceae, Leguminosae, and members of Malpighiales. Anatomical features, including vessel tangential diameter, parenchyma distribution, and ray structure, suggest a diverse angiosperm-dominated flora with strong affinities to modern tropical rainforest ecosystems. These findings provide the first detailed account of the wood flora from the Tonosí Formation and offer new insights into the composition, ecology, and biogeographic relationships of early Eocene forests in Central America.