Can it really be called a hop if the kangaroo uses both legs in the takeoff and landing? Surely even less so if it uses its tail as well?
Just saying.
It's certainly Australia's iconic animal, yet boffins have claimed the kangaroo hasn't always performed its most famous trick: hopping. Once upon a time, the Skippy the Bush Kangaroo's ancestors may not have actually bounded along, instead favouring a gait akin to a drunken human. "At best, they'd have been really clumsy …
This is as good a place as any to remark that I first read about this research in a short column on the front of the Daily Telegraph newspaper - yes, a real folding one! - on Thursday 16/10, wherein the editors, no doubt out of consideration for their SI challenged readers, had kindly converted the units. The article says "They weighed about 37.8 stone...". Decimal stones, now. Honestly, you couldn't make this stuff up.
...theoretical analyses of extinct animals are pretty much wild-ass guesstimates with very little basis in reality. A good example is the constantly upwards-shifting "theoretical maximum size of dinosaurs", which started at 30 tonnes -- no dinosaur could possibly be bigger than that, because gravity would break its bones! -- and every time a heavier dinosaur was found that theoretical limit was shifted just over the most recent find. The currently heaviest known dinosaur weighed about 65 tonnes.
The problem is that all current models have to be based on current animals -- and there just are no terrestrial 65 tonne animals to compare to today.
It's much the same with this kangaroo. The biggest roo today weighs about 70 kilos, so an extinct 225 kilo roo will be shoe-horned into the bone/muscle strength model of the current, much smaller species, and lo and behold!, the big extinct one can hardly move at all.
The other issue I have with this is that Australia was crawling with massive carnivores at the time, and getting away from them was (presumably) a priority for prey animals.
I was hoping the Demon Duck of Doom might have been a predator of these fellows, but they were around 15 million years ago.
>The other issue I have with this is that Australia was crawling with massive carnivores at the time, and getting away from them was (presumably) a priority for prey animals.
Possibly, but another possibility is if it was also a common ancestor to the common drop bear then perhaps it had no need to get away from anything. Would also explain how they got so fat.
I remember a study quite a while ago that "proved" that kangaroos could not possibly eat enough to supply the power needed to hop around all day... until someone pointed out the study calculated the energy requirements of dead-lifting the roo's weight instead of taking into account the spring-like action of the leg muscles. If memory serves, the whole think was put to rest by Terry Dawson in the 70's using kangaroos, a treadmill and a modified breathing mask.
So I'll take this new study with a sprinkle of salt until it has been properly peer-reviewed, thank you.