Early Cretaceous macrofloras 
47 
comparison to Indian Bucklandia species described 
by Seward (1917), Sahni (1932), Bose (1953a, b) and 
Sharma (1969a). Anatomically preserved Bucklandia 
axes have been associated with Williamsonia 
fructifications and Ptilophy Hum-type foliage in 
India (Sahni 1932) suggesting a bennettitalean 
affinity. Although a Roebuckia spatulata frond 
occurs on the same slab as the Bucklandia specimen 
(Figure 5E), no connection is evident or inferred. 
Ribbed axes 
Figure 10B 
1993 Striate axis; McLoughlin and Guppy; figure 
23. 
Material 
WAM P.63.30, WAM P.65.38, WAM P.65.43, 
WAM P.65.46, WAM P.65.47, WAM P.65.48, WAM 
P.66.3, WAM P.66.4, WAM P.66.6, WAM P.66.7, 
WAM P.66.8, WAM P.66.9, WAM P.66.10, WAM 
P.66.12. 
Distribution 
Broome Sandstone, Canning Basin; Bullsbrook 
Formation, Perth Basin (both Neocomian- 
Barremian). 
Description 
Several indeterminate longitudinally ribbed or 
striate axes are preserved as casts (figure 10B) and 
impressions. Axes reaching 4.5 cm wide, 13.5 cm 
long, cylindrical or flattened through compaction, 
commonly with external? longitudinal ribs 
averaging 2.5 mm apart. No axis nodes, attached 
leaves, fruits, or roots evident. 
Comments 
These axes lack diagnostic features necessary to 
assign them to any plant group, however, their size 
suggests that they may be the remains of a robust 
gymnosperm. The ribbed surface of some 
specimens invites comparison to equisetalean axes 
(e.g., Roy 1968; Drinnan and Chambers 1986), 
however, the Western Australian axes lack the 
transverse nodes typical of that group. 
Genus Rhizomopteris Schimper, 1869 
Type species 
Rhizomopteris lycopodioides Schimper, 1869; 
Carboniferous; near Dresden, Germany. 
Rhizomopteris sp. 
Figure IOC 
Material 
WAM P.89.184. 
Distribution 
Broome Sandstone (Neocomian-Barremian), 
Canning Basin. 
Description 
Irregular ?bifurcate axis bearing circular to 
elliptical protuberances set in surface depressions 
(on mould) separated by broad ridges and folds 
(Figure IOC). Protuberances reaching 3 mm wide, 7 
mm long, roughly arranged along axis in en echelon 
bands. Sporangia, leaves, and cuticle not evident. 
Comments 
A single available specimen is similar to axes 
figured by Seward (1904) and Chapman (1909) 
from the Lower Cretaceous of Victoria. Chapman 
(1909) inferred a relationship between his 
Rhizomopteris axes and Taeniopteris leaves. No such 
affinity can be deduced from the present material. 
The fossil probably represents a fern rhizome 
bearing circular to elliptical scars of abscissed 
frond rachises although no vascular traces are 
evident on the abscission zones. Rhizomopteris 
rajmahalensis Gupta, 1955 is most closely 
comparable to the Broome Sandstone specimen but 
has C-shaped rather than circular to elliptical 
rachis scars. Bose (1958) figured additional 
material comparable to Gupta's (1955) specimens 
and considered that the axes belonged to conifers. 
Coniferous axes figured by Bancroft (1913) and 
Sahni (1931) have transversely elongate abscission 
scars in contrast to the oblique or longitudinally 
elongate scars of Gupta's (1955), Bose's (1958), or 
the Broome Sandstone Rhizomopteris species. 
Genus Mesembrioxylon Seward, 1919 
Type species 
Mesembrioxylon woburnense (Stopes) Seward, 1919; 
Cretaceous; Woburn, England. 
Mesembrioxylon sp. 
Figures 10D-H 
1993 Silicified wood with Teredo burrow casts; 
McLoughlin and Guppy; figure 1. 
1994 Fossil wood; McLoughlin et al; p. 453; figs 
8a-m, 10a,b. 
Material 
UWA120186-UWA120237. 
Distribution 
The described specimens are derived from the 
Birdrong Sandstone (Neocomian-? Aptian), 
Carnarvon Basin. Other fossil woods have been 
reported from the Nanutarra Formation 
