Central American rainforests are among the most diverse biomes in the world today. However, we know little about their history because of a poor fossil record. Here, we augment previous studies based on fossil pollen of Panama with an investigation of eight species of endocarps and seeds from an upper Eocene locality near Tonosí on the Pacific coast of central Panama. Affinities at the family/order level include: Arecaceae, Vitaceae, Humiriaceae, Anacardiaceae, and Lamiales. Biogeographically, two of the Tonosí fossil taxa, Dracontomelon and cf. Leea, are interesting because they occur today only in lowland rainforests of the Old World. The new fossil genus Saxuva, together with cf. Leea, are the earliest evidence of Vitaceae (the grape family) in the Neotropics. The new genus Lacunofructus is the oldest record for Humiriaceae and supports the previously suggested Neotropical origin for the family. We interpret the Tonosí macroflora as a record of the vegetation which colonized land that emerged as part of the Eocene volcanic arc in southern Central America.
