For some time now — about four weeks — it has been the accepted wisdom that the native Australian water rat or rakali, is superior to our much-beloved platypus.

If you're unsure of why this is a fact, you need to read the very compelling case for why the rakali is our superior amphibious mammal.

TL;DR, the rakali is as soft, cute and clean as the platypus, but with one massive trump card — the rakali has been known to disembowel cane toads and gorge on their tasty insides.

This alone could have sent the minties at the Royal Australian Mint into meltdown, as they scrambled to design a 20 cent piece featuring the worthier semi-aquatic mammal.

But new information exposes a glaring omission in our earlier analysis and which, depending on your outlook, could shake the recently manufactured platypus versus rakali controversy to its very foundations.

Check your pockets. If you've got a 20 cent-piece in there, you're walking around with a cold-blooded, duck-billed psychopath, dangerously close to your nether regions.

Footage first shot at Rutherglen, in north-eastern Victoria, by Victorian photographer Ann Killeen in 2017, which has only just surfaced, shows a much darker side to the animal once thought to have been stitched together from a duck and a mole as a prank.

"I think the whole thing started in a nesting burrow and the platypus had eggs under her tail," Ann says.

Round 1: Fight

Ann believes the fight started when the rakali tried to get eggs from the platypus. ( Supplied: Ann Killeen )

By the time she got to the scene, the platypus and rakali were entangled in a tumbling mess of webbed feet and sharp claws, with only a white tail and ridiculous bill intermittently breaking the surface.

Ann positioned herself, half hanging off a bridge above the melee. From there she captured the only known photographs of a rakali-vs-platypus showdown.

Rakali on top

The rakali appeared on top early on in the stoush. ( Supplied: Ann Killeen )

In the early stages, Ann says the rakali appeared to be in control.

"[The platypus] was trying to shake [the rakali] off, but as it went on she just couldn't get rid of him."

Rakali may have started it

Rakali have been accused of biting platypus at other locations. ( Supplied: Ann Killeen )

Female platypuses have previously been found with bite marks on their feet, including one in Warrawong Sanctuary in Adelaide with its hind foot "almost reduced to a stump", platypus expert Tom Grant told Australian Geographic.

After the rakali were removed from that area, the bites stopped appearing.

But Ann says she's observed platypuses and rakali sharing the same burrow at Rutherglen without rancour.

The tables begin to turn

Ann initially thought the platypus might have spurred the rakali. ( Supplied: Ann Killeen )

Midway through their battle, the tables began to turn in favour of the platypus.

Ann says she initially suspected it may have caught the rakali with its venomous spurs located on the back of the platypus's hind feet.

But that was later ruled out when experts from the Australian Platypus Conservancy analysed the footage and identified the platypus as female.

Only the male platypuses carry venom.

Damnit, don't you dare give up!

The rakali was able to get to the surface for air less as the fight wore on. ( Supplied: Ann Killeen )

The rakali was being held under by the platypus, and as time passed, was making it to the surface for breath less often.

"It went on for about 20 to 30 minutes as the platypus dragged him across the river," Ann says.

A spokesperson for the National Platypus Conservancy said he believed the platypus simply overpowered the rakali.

"[The platypus] managed to drown the water-rat by holding it underwater while presumably squeezing its mid-section forcefully," he said.

So why did this fight happen?

The white balls may be platypus eggs, rakali testicles, or something else entirely. ( Supplied: Ann Killeen. )

Platypus lay two soft, sticky eggs which they incubate under their tail.

Ann believes the rakali was likely looking for a quick meal, and tried to get the eggs from under the platypus.

She says her hypothesis is backed up by a photo she snapped, which may show the two eggs still stuck to the animal's tail.

"It's either that or the rat had some very big testicles," she says.

The Australian Platypus Conservancy favoured the big-testicle hypothesis, saying any eggs would have likely detached during the fight.

"It's very hard to believe that these would remain stuck to a female's fur through the course of a very active and physical close interaction in the water," the spokesperson said.

Though they remained unconvinced by either explanation.

A third, admittedly unsubstantiated, theory says that platypus are actually a short-tempered and vindictive animal, with murderous hearts. There is zero evidence to back this up.

Where does that leave us?

In happier times before his life was cut short by a platypus. ( Supplied: Ann Killeen )

So does this change the hitherto undisputed superiority of the rakali over the platypus?

For Team Platypus, this will no doubt be twisted into proof that theirs is Australia's finest semi-aquatic, web-footed, plush toy in waiting.

Team rakali are too devastated to comment at this time.

Maybe more to come.