Araucaria section Eutacta macrofossils from the Cenozoic of southeastern Australia

Abstract

PREMISE OF RESEARCH. We collate and interpret previously undescribed foliar material of Araucaria section Eutacta from Australian Cenozoic sediments. METHODOLOGY. The fossils we describe here were collected over several decades and were identified by direct comparisons with extant and fossil species using light and scanning electron microscopy. PIVOTAL RESULTS. Fossil leaves and leafy shoots of three new species of Araucaria section Eutacta (A. macrophylla, A. mollifolia, and A. balfourensis), along with new records of the previously described A. planus, are described from eight localities in southeastern Australia, spanning the early Eocene to the early Miocene. CONCLUSIONS. These well-preserved fossils add significantly to our knowledge of Araucaria and confirm the dominance of the section Eutacta compared with other sections in the region during that time. The range of leaf morphology exhibited is similar to that seen in extant New Caledonian species and probably reflects past phases of radiation in similar wet climates.