Systematics of cretaceous and tertiary Nothofagoxylon:: implications for Southern Hemisphere biogeography and evolution of the Nothofagaceae

Fossil woods with greatest anatomical similarity to modern Nothofagaceae are traditionally assigned to the organ genus Nothofagoxylon Gothan. All fossil wood records of Nothofagoxylon were re-evaluated so that recently collected specimens from the Antarctica Peninsula region could be assigned to taxa within this organ genus. Widespread synonymy was found within the published records of Nothofagoxylon, so that of the 16 described species, only seven were retained. Six of these fossil species were found to be present in Antarctica. In undertaking this review, some lauraceous woods assigned to Laurinoxylon Schuster were found to be nothofagaceous. Temporal and spatial patterns of occurrence of the Nothofagoxylon wood type help support current views that the centre of origin of the Nothofagaceae was within the Antarctic Peninsula-South America region during the Campanian followed by radiation into the lower southern latitudes throughout the Tertiary.