Overview
- Published January 22 in Scientific Reports, the study reexamines giant kangaroo locomotion using biomechanical tests rather than simple scaling of modern species.
- The team measured 94 modern and 40 fossil specimens across 63 species, focusing on fourth metatarsal strength and whether the calcaneus could accommodate sufficiently large Achilles tendons.
- Results overturn earlier claims that kangaroos above roughly 150–160 kilograms could not hop, showing extinct giants had shorter, stouter feet and broader heels suited to withstand hopping forces.
- The authors conclude hopping was mechanically feasible but energetically inefficient at large size, so it was likely used only in short bursts such as traversing rough ground or evading predators like Thylacoleo.
- Fossils indicate a varied movement repertoire that likely mixed brief hops with bipedal walking or quadrupedal movement, with species such as Procoptodon goliah estimated at about 240–250 kilograms and extinct roughly 40,000–50,000 years ago.