Illuminating the unanticipated diversity of tree-climbing kangaroos in Australia and New Guinea in the recent geological past

A project undertaken at the School of Veterinary and Life Sciences, Murdoch University, and supervised by Dr Natalie Warburton

An ability to climb trees is known for modern tree-kangaroos (Dendrolagus) and their extinct ancestors (Bohra) (Prideaux & Warburton 2008, 2009). Study of the skeletons of several new Pleistocene (2.6–0.01 Myr ago) kangaroo species, including the enigmatic genus Congruus and “giant” rat-kangaroo Propleopus, has led to surprising observations of adaptations consistent with tree-climbing. Further, hind-limb bones from a 3.5-Myr-old site in New Guinea tentatively referred to the forest-wallaby genus Dorcopsis (Plane 1967) also preserve a number of anatomical features that bespeak an ability to climb trees. The main aim of this study is to verify whether these species were indeed built for climbing, and to synthesise our results with other lines of evidence to shed light on the hitherto-unanticipated ecological roles that these species may have filled in Australian ecosystems.

The key objectives of this study are to:
  1. Completely describe Pleistocene skeletal material referable to species of Congruus and Propleopus from the Nullarbor (WA), Naracoorte (SA) and Wellington (NSW) caves, and the large extinct species referred to Dorcopsis from New Guinea;
  2. Make comparisons with skeletal material of other macropods and climbing mammals (e.g., tree-kangaroos, primates, sloths, bears) to functionally assess their likely arboreal abilities and to determine their likely mode of climbing;
  3. Generate the most accurate estimates yet of body size in these extinct species using skull / jaw, femur and heel-bone dimensions (with high correlation coefficients in modern macropods) as body-size proxies;
  4. Combine dental-microwear data, which provide dietary insights, with anatomical and body-size deductions to provide the most detailed interpretations yet of the ecology of these intriguing kangaroos and the communities in which they lived.
Research Team:

Natalie Warburton (Murdoch University, Perth) and Gavin Prideaux (Flinders University, Adelaide).