Libocedrus Macrofossils from Tasmania (Australia)

Fossilized Libocedrus (Cupressaceae) foliage from three Tasmanian fossil sites—Regatta Point (∼52–51 Ma), Lea River (∼32–30 Ma), and Balfour (∼29–21 Ma)—is described, and three new species are recognized. Brief descriptions of extant Libocedrus precede the fossil descriptions. Libocedrus leaf morphology has remained much the same for 30 Myr. Variations in leaf size, stomatal frequency, size, and distribution are indicative of prevailing climatic conditions. Although Libocedrus appears to have had a quite widespread distribution in southeastern Australia in the past, the genus is now found only in New Zealand and New Caledonia. Its disappearance from Tasmania and the Australian mainland is linked to continental rearrangement and global climate change. A single specimen from Balfour shares features common to extant Libocedrus and the closely related monotypic cupressaceous genus Diselma.