Price et al.: koala palaeoecology 
45 
Fig. 4. Photographs of fossil koala 
teeth from eastern Australia. (A) 
QMF52288, LM 2 of Phascolarctos 
sp., site QML1384, Mt. Etna. (B) 
QMF52289, RM 1 2 or 3 metacone 
fragment of Ph. ?stirtoni, Chinchilla. 
(C) QMF52290, RM 2 protocone 
fragment of Ph. ?stirtoni, Marmor. 
similar dentitions to Ph. cinereus (Bartholomai, 1968), 
the underlying assumption is that they had broadly similar 
habitat and dietary preferences (Archer et al., 1991). 
The Chinchilla Local Fauna represents a rich and diverse 
assemblage of fossil taxa, many of which are considered to 
be restricted solely to Pliocene deposits (e.g., Euryzygoma) 
(Archer, 1977b). The fauna includes molluscs, fish, lungfish, 
crocodiles, turtles, squamates, birds, rodents, dasyurids, 
bandicoots, diprotodontoids, wombats, marsupial lions, 
kangaroos, wallabies, and rodents (Bartholomai & Woods, 
1976; Hutchinson & Mackness, 2002). The Pliocene 
palaeohabitat of the region was interpreted as consisting of 
a seasonal wetland component, with grasslands interspersed 
with complex and mature woodlands (Hutchinson & 
Mackness, 2002). The interpreted Pliocene habitat differs 
significantly from the habitats of the region today, which 
are dominated by open Acacia and Eucalyptus populena 
woodlands and grasslands (Fensham & Fairfax, 1997). 
Dawson (2004) recently described the first record of a 
potentially arboreal tree kangaroo from the assemblage. 
Thus, the identification of Phascolarctidae gen. et sp. indet. 
and Phascolarctos ?stirtoni significantly increase the known 
diversity of arboreal forms within the Chinchilla Local 
Fauna. Although the presence of such taxa provides support 
for the former existence of large-scale complex woodlands, 
they do not necessarily indicate Pliocene closed-forest in the 
region (Dawson, 2004). The modern Koala, Ph. cinereus, is 
extant in the region, whilst tree kangaroos are now restricted 
to rainforest communities in northeastern Queensland and 
New Guinea. Tree kangaroos are also absent from nearby 
intensively-sampled Late Pleistocene deposits of the eastern 
Darling Downs and Gore (Bartholomai, 1977; Price & Sobbe, 
2005; Price & Webb, 2006; Price et al., 2009). Generally, 
both the Late Pleistocene Darling Downs and Gore fossil 
faunas are dominated by terrestrial, non-arboreal, open 
woodland and grassland taxa (Bartholomai, 1977; Price, 
2002, 2005; Price & Sobbe, 2005; Price et al., 2005, 2009; 
Price & Webb, 2006) with very few species that also occur 
in Pliocene deposits (a possible exception being a species of 
marsupial “tapir”, Palorchestes (Price & Hocknull, 2005)). 
Thus, those data suggest that significant habitat and faunal 
reorganization occurred in the Chinchilla region between 
the Pliocene and Pleistocene, presumably reflecting the 
contraction of dense woodlands and expansion of open 
woodlands and grasslands. A local reduction in habitat 
heterogeneity (associated with an expansion of open habitats) 
is also evident between the Late Pleistocene and Recent 
(Price & Sobbe, 2005). Therefore, those observations suggest 
that significant regional habitat changes have been underway 
since at least the Middle Pliocene. 
The Middle Pleistocene Marmor (Site QML1420) 
faunal assemblage includes dasyurids, thylacinids, 
possums, marsupial lions, wombats, diprotodontoids, 
macropodoids, and rodents (Longman, 1925; Hocknull, 
2005). The palaeohabitat is interpreted as representing a 
mosaic vegetation complex comprised of sclerophyll forest 
and grasslands based on the presence of closed forest taxa 
(e.g., tree kangaroos and pademelons) and open woodland 
taxa (e.g., grazing kangaroos and wombats) (Hocknull, 
2005). The presence of Phascolarctos ?stirtoni supports an 
open woodland component of the Pleistocene habitat. The 
interpreted palaeohabitat differs from the modern habitat 
of the region, which is dominated by open woodlands and 
grasslands, with refugial forest and vine thickets restricted 
to the hillsides. Although some arboreal taxa such as tree 
kangaroos are now locally extinct, extant Koala populations 
persist in the region. 
Site QML1384 (Mt. Etna, Unit “L.U.”) contains a diverse 
faunal assemblage including squamates, turtles, dasyurids, 
bandicoots, possums, kangaroos, bats, and rodents. Hocknull 
(2005) suggested that the palaeohabitat was an angio sperm- 
dominated rainforest based on the presence of “specialist” 
extant rainforest taxa such as cuscuses ( Strigocuscus ), striped 
possums ( Dactylopsila ), tree kangaroos ( Dendrolagus ), 
and giant white-tailed rats ( Uromys ). The new record of 
Phascolarctos sp. in the assemblage suggests the possibility 
that a more sclerophyllous open-forest habitat type was 
also sampled in the deposit. That interpretation does not 
necessarily refute the hypothesis that the palaeohabitat was 
predominantly rainforest, but it does suggest that Eucalyptus 
may have formed a minor vegetative component of the 
palaeohabitat. Thus, the Middle Pleistocene vegetation 
surrounding the QML1384 “L.U.” deposit may have 
consisted of a mosaic of habitat types. Such mosaic habitat 
types appear to be characteristic of many pre-Holocene 
Australian fossil deposits (Lundelius, 1983, 1989; Price, 
2005). Alternatively, the deposit represents a significantly 
temporally-mixed assemblage. U/Th dating of the deposit 
(Table 1) provides only minimum ages of deposition 
and thus, the precise duration of accumulation cannot be 
determined. The provenance of fossil material is unclear. It 
is possible that different habitats occurred, and were sampled 
proximal to the cave over the period of deposition. However, 
this hypothesis cannot be tested on the basis of the data 
