OFR 151.pdf - CRC LEME

genera are Gymnostoma (Casuarinaceae) and Eucryphia (Eucryphiaceae); extinct genera
include Banksieaephyllum (Proteaceae) (Hill 1991, Carpenter et al. 1994b, Scriven and Hill
1995, Taylor and Hill 1996).
The flora is an important one, not only because it includes taxa whose NLRs are widely
separated in the South-west Pacific region, but also because of the diversity of morphological
adaptations. For example the closest relatives of Gymnostoma (G. antiquum) and
Banksieaephyllum (B. taylorii) occur in relatively dry areas in (tropical) New Guinea and
(humid) southwestern Western Australia, respectively. The latter is the earliest known
example of scleromorphy recorded in an Australia Tertiary angiosperm.
Inferred climate
Well-defined growth rings in the fossil gymnosperm wood point to tree growth being
controlled by strong seasonal fluctuation in mean temperature since neither photoperiod nor
precipitation are likely to have been limiting factors. Based on bioclimatic data from extant
NLRs, Taylor et al. (1990) propose that mean annual temperatures were mesotherm (~14-
20 0 C) but frost-free. To what degree the cool/wet conditions at Palaeolake Bungarby were
due to elevation and orographic cloudiness reducing evapo-transpiration on the Southeastern
Highlands of New South Wales is uncertain.
1.1.7 Tasmania
No known record.
1.2 Microfloras
Early and/or Late Paleocene marine sediments are widespread in the offshore Carnarvon,
Canning and Bonaparte Basins but are seldom sampled (Apthorpe 1988). Dredge samples
from the continental shelf off the central and northern New South Wales coast include some
rocks that preserve Paleocene dinoflagellate floras (R. Helby pers. comm.) but information on
the associated spore-pollen content is unavailable. Other Paleocene sequences in the same
category occur off the western margin of Tasmania margin, and in north-west Tasmania (e.g.
Sorell Basin) and south-west Western Australia (Kings Park Shale). For this reason what is
currently known about the Paleocene flora and vegetation mostly comes from
Lygistepollenites balmei Zone microfloras preserved in subcrop in southeastern Australia.
1.2.1 North-West Australia
No known record.
1.2.2 North-East Australia
1. Northern Tablelands of New South Wales
Palaeosols and braided stream deposits underlie latest Paleocene [~54 Ma] basalts at
elevations above 800 m on the Mt. Royal Range and sites near Tamworth on the Northeastern
Tablelands (Morgan 1978, Martin et al. 1987).
Microfloras recovered from Mt. Royal are dominated by araucarians (Araucaria), podocarps
(Dacrydium, Lagarostrobos, Podocarpus-Prumnopitys) and ferns (Cyatheaceae,
Gleicheniaceae). Angiosperm pollen are relatively rare, with the most common taxon being
small, nondescript Proteaceae. Nothofagus is absent. The Tamworth assemblages are
dominated by Podocarpaceae (Dacrycarpus, Lagarostrobos, Podocarpus-Prumnopitys), but
204