Banksieaephyllum taylorii ( Proteaceae) from the late paleocene of New South Wales and its relevance to the origin of Australia's scleromorphic flora

Abstract

Leaf specimens from Late Paleocene sediments in New South Wales are assigned to a new species of Banksieaephyllum, B. taylorii. In gross morphology the leaves are indistinguishable from those of extant Dryandra formosa, and similar to a few other species of Dryandra and Banksia. These species have pinnately lobed leaves and are now confined to south-western Australia. In cuticular morphology, B. taylorii is most similar to Banksia species from subgenus Banksia, section Oncostylis. One species in this section, B. dryandroides, also has pinnately lobed leaves. The fossil specimens demonstrate that subtribe Banksiinae had differentiated by the Late Paleocene and represent the earliest record of angiosperm scleromorphy in Australia to date. The superficial placement of the stomates compared with most modem Banksiinae supports the hypothesis that xeromorphy in this group generally increased in response to the development of less mesic climates in the Late Tertiary.