Washington, Oct 16 (IANS): Giant kangaroos which are now extinct could not hop and used a more rigid body posture to move their hind limbs one at a time, says a study.

The 'short-faced', large-bodied sthenurine kangaroos - a now extinct relative to modern-day kangaroos - first appeared in the middle Miocene and became extinct in the late Pleistocene era.

The largest of these kangaroos had an estimated body mass of 240 kg - three times the size of modern kangaroos.

The large kangaroo species lacked many specialised features for rapid hopping, but had an anatomy suggesting they supported their body with an upright posture, showed the study.

They could support their weight on one leg at a time using their larger hips, knees, and stabilised ankle joints.

"Sthenurines adopted a walking gait on two hind legs. This gait may have been used as an alternative gait to using the tails as fifth limb at slower speeds," said Christine Janis from the Brown University in the US.

The study was published in the journal PLOS ONE.