Early Cretaceous macrofloras 
55 
and its distribution in Neocomian strata of the 
Surat and Gippsland Basins. 
The floras most closely comparable to the 
Western Australian assemblages are those from the 
Algebuckina Sandstone (Eromanga Basin) at Mt 
Babbage, South Australia, and from the Lees 
Sandstone and overlying beds (Carpentaria Basin), 
at Bauhinia Downs, Northern Territory. The 
Algebuckina Sandstone incorporates Middle 
Jurassic to Neocomian sediments (Moore 1986; 
Wiltshire 1989). The macrofloras at Mt Babbage 
occur in the upper part of this unit and are 
probably of Neocomian age. Although requiring 
systematic revision, the Mt Babbage flora shares 
several taxa with the Western Australian 
assemblages (Glaessner and Rao 1955), Most 
notable are the co-occurrences of Nathorstianella 
babbagensis, Ptilophyllum cutchense, and Taeniopteris 
daintreei. (White 1961b, 1966). Tire Bauhinia Downs 
flora likewise shares several key taxa with Western 
Australia including Ptilophyllum cutchense, 
Microphyllopteris gleichenioides, Hausmannia sp., and 
Taeniopteris daintreei, and owing to tire abundance 
of bennettilaleans and lack of ginkgophytes, is of 
probable Neocomian rather than Aptian age as 
suggested by Dettmaim et al. (1992). 
A Neocomian-Barremian age is proposed for the 
collective Western Australian terrestrial plaxrt 
assemblages described here. Accumulation of plant 
remains in several regions along the continent's 
western margin during the Neocomian-Barremian 
probably occurred as part of a single phase of 
widespread fluvio-deltaic sedimentation 
associated with continental breakup, marginal 
basin sag, and regional and global sea-level 
fluctuations at that time (McLoughlin, et al. 1994). 
Comparisons with other Gondwanan floras 
The Western Australian Cretaceous floras share 
several genera and possibly some species with the 
Rajmahal, Kutch, and Jabalpur floras of India. The 
Rajmahal Series has been variously assigned to: the 
lower, middle, or upper Jurassic according to 
traditional palaeobotanical studies (Feistmantel 
1877a; Halle 1913; Sahni and Rao 1933); the Lower 
Cretaceous based on paly nostratigraphy (Playford 
and Cornelius 1967); and the Albian according to 
radiometric (K-Ar) dating (McDougall and 
McElhinny 1970). Sukh-Dev (1987) re-evaluated the 
stratigraphic relationships of the Indian Mesozoic 
macrofloras and established 12 assemblage zones 
from the Early Triassic to latest Cretaceous. He 
reassigned the lower Rajmahal assemblages to the 
Lower Cretaceous. Sukh-Dev's (1987) 
Dictyozami tes-Pterophyll um-Anomozamites 
Assemblage Zone corresponds most closely to the 
Western Australian Cretaceous floras by its high 
proportion of bennettitaleans, Taeniopteris, and the 
occurrence of comparable species of ferns 
[Gleichenites ( =Microphylhpteris), Hausmannia, and 
Cladophlebis] and Conifers [Araucaria, Araucarites 
(cone scales and cones), and Elatocladus]. This 
Indian zone differs from the Western Australian 
assemblages by its possession of ginkgophyte and 
Pachypteris species and its lack of Phyllopteroides, 
Roebuckia, and Nathorstianella species. The 
Dictyozamites-P ter ophyll um-Anomozamites 
Assemblage Zone is best represented in the 
Jabalpur Formation (Chaugan Forest district) of 
Madhya Pradesh (Crookshank 1936), the Lower 
Rajmahal Formation (intertrappean beds 1-3, 
Rajmahal Hills) of Bihar (Bose and Sah 1968; 
Sharma 1969b, 1971, 1975; Zeba-Bano et al. 1979), 
and the lower Bhuj Formation of Kutch (Bose and 
Banerji 1984) together with a number of lesser- 
studied units in peninsula India, Sri Lanka, and 
Nepal (see Sukh-Dev 1987). Certain genera (and 
perhaps species) from Sukh-Dev's (1987) 
succeeding Allocladus-Brachyphyllum-Pagiophyllum 
Assemblage Zone and Weichselia-Onychiopsis- 
Gleichenia Assemblage Zone are also shared with 
the Western Australian floras but these 
assemblages appear to be more akin to the 
Victorian Zone C (?late Neocomian-early Albian) 
floras. 
The Tico (Baquero Formation) Flora of Patagonia 
(Argentina) has a number of conifer, fern, and 
bennettitalean genera in common with the Western 
Australian Cretaceous floras (Herbst 1962a; 
Archangelsky 1963a,b,c, 1964a,b; Archangelsky and 
Baldoni 1972) but the number of shared taxa are 
fewer than between the Western Australian and 
Indian assemblages. The Baquero Formation has 
been assigned a late Barremian to early Aptian age 
based on its palynoflora (Archangelsky et al. 1984) 
and most notably differs from the Western 
Australian Early Cretaceous assemblages by its 
possession of angiosperm remains (Archangelsky 
1963c; Romerro and Archangelsky 1986). It 
probably has greater floristic affinities with the 
Victorian Zone C assemblages. 
A number of other lesser-studied Early 
Cretaceous floras from Argentina show distinct 
similarities to the Western Australian assemblages. 
Though dated as Aptian on the basis of associated 
ammonoid faunas, the Kachaike Formation, Santa 
Cruz, has yielded Microphyllopteris, Hausmannia, 
Cladophlebis, and Ptilophyllum species strikingly 
similar to those from the Broome Sandstone 
(Longobucco et al. 1985). The Apeleg Formation, 
Chubut, also contains species of Taeniopteris, 
Cladophlebis, and Ptilophyllum similar to those from 
Western Australia and has been assigned a 
Hauterivian-Barremian age (Baldoni and de Vera 
1980). Although some elements (e.g., Ticoa, Zamites, 
and Cycadolepis spp.) differ, the Spring Hill 
Formation of southern Argentina and Chile also 
has a number of bennettitaleans, ferns, and 
