CONCLUSIONS

Plant species identified in the Rio Puerto Viejo deposit lived in a lowland neotropical forest of Northeastern Costa Rica during the Pleistocene (younger than 915 ka), with cooler paleotemperatures than at present. Sedimentary analysis of the gray layer from which the fossils were found suggests a fluvially reworked volcanic or primary airfall deposit. Except for a single leaflet, all the leaves are fragmented suggesting a fluvial deposit but further taphonomic analysis is required to confirm this assessment. The fossil flora is similar to modern Costa Rica tropical forest and shows a biogeographic connection with northern South America.