Fossil leaves of Banksia, Banksieae and pretenders: resolving the fossil genus Banksieaephyllum

Abstract

The genus Banksieaephyllum, originally erected for cuticle-bearing fossil leaves of subtribe Banksiinae (Proteaceae subfamily Grevilleoideae, tribe Banksieae), is reassessed. Of the 18 described species, nine are accepted within Banksia, including Banksieaephyllum obovatum Cookson & Duigan, which is synonymised with B. laeve Cookson & Duigan on the basis of new cuticular preparations. Two other species are transferred to Banksieaefolia gen. nov., a genus erected for Banksieae of uncertain affinities, and which presently includes only fossils that probably belong to subtribe Musgraveinae. The seven other Banksieaephyllum species lack definitive characters of Proteaceae (i.e. brachyparacytic stomata and annular trichome bases) and do not have Banksieae-type cylindrical trichome bases. These species are, therefore, not accepted as Proteaceae and are transferred to Pseudobanksia gen. nov., together with another fossil Banksia-like leaf species, Phyllites yallournensis Cookson & Duigan. Lectotypes are chosen for Banksia fastigata H.Deane, Banksieaephyllum acuminatum Cookson & Duigan, Banksieaephyllum angustum Cookson & Duigan and Banksieaephyllum laeve Cookson & Duigan. Implications arising from the re-assessment of Banksieaephyllum include clarification of biome conservatism in Banksieae; Banksia has long had an association with relatively open, sclerophyllous vegetation, and Musgraveinae with rainforest. Pseudobanksia and Banksia share convergent traits, but in contrast to Banksia, Pseudobanksia failed to survive the drying climates and increased fire-frequencies of the Neogene.

Pinnule and Stomatal Size and Stomatal Density of Living and Fossil Bowenia and Eobowenia Specimens Give Insight into Physiology during Cretaceous and Eocene Paleoclimates

“…8). The Lowana Road vegetation was distinct from that at Anglesea and Nerriga, with evidence for mangrove vegetation (Pole and Macphail 1996), diverse broadleaved angiosperms (Carpenter et al 2007;Carpenter et al 2012), diverse and common conifers (Bigwood and Hill 1985;Hill and Bigwood 1987;Hill 1990), and other gymnosperms (McLoughlin et al 2008). The vegetation may have been open canopied (Pole 1998).…”

New Macrofossils of the Australian Cycad Bowenia and Their Significance in Reconstructing the Past Morphological Range of the Genus

“…A regional Early Eocene flora was reported by Pole (2007) from dispersed cuticular remains. Mangrove species (e.g., the southernmost record of the mangrove palm genus Nypa; Pole and Macphail 1996) occur widely, and the (Rozefelds et al 2017), and probable rainforest angiosperms (Carpenter et al 2007;Conran et al 2009). Conifer fossils are diverse and common regionally, and they include representatives of the Araucariaceae (Bigwood and Hill 1985;Hill and Bigwood 1987;Hill 1990), Cupressaceae (Paull and Hill 2009), and Podocarpaceae (Wells and Hill 1989;Hill and Carpenter 1991).…”

Early Eocene plant macrofossils from the Booval Basin, Dinmore, near Brisbane, Queensland

“…(Cookson and Duigan, 1950;Hill and Christophel, 1988). Some of these fossil taxa are clearly Proteaceae, but Carpenter et al (2016) have pointed out that some do not have epidermal details typical of Proteaceae, and are therefore unlikely to belong in the family. Of relevance here is a taxon that was first described as Banksia fastigata (Deane, 1925), which is smaller, but has a similar venation and margin as the Dinmore material.…”

“…This was placed in Banksieaephyllum by Cookson and Duigan (1950), a genus accepted as Proteaceae by Hill and Christophel (1988). Carpenter et al (2016) reconsidered the material and concluded that the stomata "do not appear brachyparacytic," and both the form and location (restricted to epidermal cell junctions) Parataxon: DINM-JJI Figure 12 Reference specimen. Parataxon JBJ Figure 14 Reference specimen.…”