Data from: Dietary responses of Sahul (Pleistocene Australia–New Guinea) megafauna to climate and environmental change

Throughout the late Quaternary, the Sahul (Pleistocene Australia–New
Guinea) vertebrate fauna was dominated by a diversity of large mammals,
birds, and reptiles, commonly referred to as megafauna. Since ca.
450–400Ka, approximately 88 species disappeared in Sahul, including
kangaroos exceeding 200kg in size, wombat-like animals the size of
hippopotamuses, flightless birds, and giant monitor lizards that were
likely venomous. Ongoing debates over the primary cause of these
extinctions have typically favored climate change or human activities.
Improving our understanding of the population biology of extinct megafauna
as more refined paleoenvironmental data sets become available will assist
in identifying their potential vulnerabilities. Here, we apply a
multiproxy approach to analyze fossil teeth from deposits dated to the
middle and late Pleistocene at Cuddie Springs in southeastern Australia,
assessing relative aridity via oxygen isotopes as well as vegetation and
megafaunal diets using both carbon isotopes and dental microwear texture
analyses. We report that the Cuddie Springs middle Pleistocene fauna was
largely dominated by browsers, including consumers of C4 shrubs, but that
by late Pleistocene times the C4 dietary component was markedly reduced.
Our results suggest dietary restriction in more arid conditions. These
dietary shifts are consistent with other independently derived isotopic
data from eggshells and wombat teeth that also suggest a reduction in C4
vegetation after ~45 Ka in southeastern Australia, coincident with
increasing aridification through the middle to late Pleistocene.
Understanding the ecology of extinct species is important in clarifying
the primary drivers of faunal extinction in Sahul. The results presented
here highlight the potential impacts of aridification on marsupial
megafauna. The trend to increasingly arid conditions through the middle to
late Pleistocene (as identified in other paleoenvironmental records and
now also observed, in part, in the Cuddie Springs sequence) may have
stressed the most vulnerable animals, perhaps accelerating the decline of
late Pleistocene megafauna in Australia.