Ancient kangaroos did not hop

Oct 15, 2014, 10:48 PM EDT
In this handout image provided by Taronga Zoo, an unnamed baby Goodfellows Tree Kangaroo joey is seen in it's mothers pouch on February 24, 2014 in Sydney, Australia.
Handout/Getty Images

Recent research suggests that ancient kangaroos -- or giant marsupial relations to modern-day kangaroos -- did not hop, and instead just walked on two legs. They lived about 100,000 to 30,000 years ago. LiveScience elaborates:

The largest kangaroo (Procoptodon goliah) weighed an estimated 529 pounds (240 kilograms), or about three times the weight of today's kangaroos. Their enormous size may have prevented them from hopping, and analyses show that their bodies were configured differently than their modern ancestors.
For instance, the anatomy of sthenurines suggests they held their bodies in an upright position, and could support their weight on one leg at a time by using their large hips, knees and stabilized ankle joints.
As well as discovering that their hind limbs and spines were different to the red and grey kangaroos of today, the team realised that it was unlikely that an animal that weighed 550lbs would be able to hop. It is unknown if they evolved to be bipedal or they originally jumped but became too large.
"I don't think they could have gotten that large unless they were walking," said Christine Janis, professor of ecology and evolutionary biology at Brown University, US.
“We need to consider that extinct animals may have been doing something different from any of the living forms, and the bony anatomy provides great clues.”