Trophic and taxonomic restructuring of Sahul’s large-bodied animal community since the Late Pleistocene

Communities of large-bodied animals have changed in composition since the Late Pleistocene, triggering flow-on effects for modern ecosystems. However, the details of these changes remain unclear. We examined the composition of Sahul's large (>10 kg), non-marine tetrapod community between 100,000 years ago (Late Pleistocene), 1788 (prior to European invasion), and today by quantifying changes in species richness and the proportion of species in different trophic guilds and taxonomic classes. Richness fluctuated through time (between 103 and 37 species), with mammals and herbivores most affected. Most herbivores and invertivores were mammals (>95% and 100%, respectively), most carnivores were reptiles (≥79%), and most omnivores were birds (>62%). In the Late Pleistocene, extinction risk differed among trophic guilds and taxonomic classes-mammals and herbivores were over-represented among extinctions. Although mammals remain the most vulnerable class, post-1788 patterns do not show large differences among taxonomic or trophic groups. Community composition also shifted due to the arrival of species: two large species arrived before European invasion, and 21 have been introduced since. These results indicate substantial changes in the trophic and taxonomic composition of Sahul's large-bodied fauna, pointing to shifts in the structure and function of its ecological communities.