Tertiary Nothofagus macrofossils from Cethana,Tasmania

Two new Tertiary species of Nothofagus from the Early Eocene-Oligocene deposit at Cethana represent the first reports of fossil species which are not closely related to the extant Australian species N. moorei and N. cunninghamii. N. cethanica sp. nov. is most closely related to the extant New Zealand species N. fusca and N. truncata and gives further evidence of the relatively slow evolution within this genus. The other specimen is indistinguishable from extant adult N. gunnii leaves, and has been assigned to that species. This fossil shows that the deciduous habit was probably already present in N. gunnii by the Oligocene, and this may have helped N. gunnii to survive the Late Tertiary/Quaternary glaciations. Juvenile N. gunnii foliage gives some insight into the possible origins of this species, which may have been from the same ancestral stock as N. fusca, N. truncata, and N. cethanica.