Procoptodon goliah. Image by By Nobu Tamura – https://spinops.blogspot.com/2020/07/procoptodon-goliah.html, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=99474302
Dear Readers, an adult red kangaroo is quite scary enough when it decides that it doesn’t like you: Roger the red kangaroo went viral after a video of him crushing a steel bucket as if it was a paper cup highlighted the strength of these animals.
Roger the ‘ripped’ red kangaroo from the Kangaroo Sanctuary in Alice Springs (Photo from https://www.theguardian.com/world/2018/dec/10/death-of-roger-the-ripped-kangaroo-sparks-outpouring-of-grief-on-social-media)
Imagine, then, meeting up with one of their ancestors. Procoptodon goliah became extinct about 40,000 years ago. Although they were only a little taller than Roger, at 2 metres, they weighed a gob-smacking 240 kilograms (Roger was 89 kilograms). And that caused something of a problem for scientists. Was this massive animal actually able to hop around like today’s kangaroos?
One of a group of extinct animals known as the sthenurine or short-faced kangaroos, Procoptodon was thought to have been unable to hop, because the impact of landing would have broken their legs, but more importantly their Achilles tendons would have snapped. Scientist Megan Jones, at the University of Manchester here in the UK, notes that the tendons in kangaroos alive today are often dangerously close to snapping, but this is because the Achilles tendon holds a lot of the elastic energy that enables the kangaroo to power itself through a series of hops – in fact, this is a very energy-efficient way of getting around.
However, Procoptodon is not just a scaled-up version of a red kangaroo – their feet are shorter, and their calcaneus, or heel bone, is wider. Jones believes that because of this, the bones of this ancient kangaroo would have been more resistant to bending, and could have accommodated a larger Achilles tendon.
While hopping probably wasn’t Procoptodon’s main method of getting around, it could certainly have thundered across the outback when needed (though goodness knows what was brave enough to chase it). Current day kangaroos also use a range of different ways to get about: they wander around on four legs, sit up like a tripod using their tail and, of course, speed around the place when necessary. I always think that kangaroos travelling at speed are extremely elegant animals, and sometimes wonder why more large animals didn’t choose this as a method of locomotion (although it’s very popular in small animals, with jerboas and springhaas both choosing to boing about the desert/savannah). All in all, I am delighted to think of these massive animals crashing about, and am only sorry that there aren’t any left for us to witness.
You can read the whole article here
Procoptodon hopping – image by Megan Jones