SEEDS OF AMPELOCISSUS, CISSUS, AND LEEA (VITALES) FROM THE PALEOGENE OF WESTERN PERU AND THEIR BIOGEOGRAPHIC SIGNIFICANCE

摘要

Seeds of Vitaceae and Leeaceae are recognized from the late Early Oligocene of Belen, near Talara, northern coastal Peru. Reexamination of fossils described by Berry in the 1920s, supplemented by newly collected specimens, leads us to accept his identifications of Ampelocissus and Cissus. In addition to the two species previously recognized (Ampelocissus bravoi [Berry] Berry and Cissus willardii Berry), the new material allows recognition of another species of Cissus-that is, Cissus lombardii sp. n.-and confirms the presence of Leea, represented by Leea olssonii (Berry) comb. n. These well-preserved fossils show seed characters unequivocally diagnostic for these three extant genera and include two distinct morphotypes of Cissus, indicating that this genus was already diversified in South America by ～28.5 million years ago. The fossils are biogeographically informative because Ampelocissus and Leea are absent from South America today, and the latter is now native only to the Old World tropics. Confirmation of both Vitaceae and Leeaceae from the Oligocene of Peru is significant as an indication that the Vitales were well diversified by this time in South America.