An excerpt from my favourite scene in the 1987 film, the Princess Bride:
Westley: Rodents of Unusual Size? I don’t think they exist.
[R.O.U.S. attacks Westley]
Why is that my favourite scene? Because I laugh every time I watch it. The R.O.U.S. is just so ridiculous-looking and shows up right after Westley disbelieves its existence.
For the devoted readers out there, you’re maybe wondering what my obsession with R.O.U.S.es is because I’ve written about them before, but somehow they capture my imagination unlike any other strangely-proportioned creature. I think it has something to do with the comedic effect of reversing the expectation of something cute.
The R.O.U.Ses from the Princess Bride have come to set the standard for overgrown rodents, but sometimes reality is stranger than fiction.
The largest discovered member of the rodent family (membership to which depends on having a pair of razor-sharp, ever-growing incisors), Josephoartigasia monesi is estimated to have been the size of a bull.
Since only its skull was discovered, the weight has been debated. The original discovery paper pegged the mass of monstrous mulch muncher at 1211kg on average with a maximum of 2584kg. To put that into perspective, that’s anywhere from 1 to 4 dairy cows. A more recent study, however, showed that depending on the part of the skull you use to predict the mass of the full creature, J. monesi could have weighed from as low as 356kg (half a cow) to 1534kg (back up to the 2-cow range). Even if the creature was as small as 356kg, that still makes it nearly 6 times heavier than the current rodent heavyweight champion of the world,
Floyd Mayweather the capybara.
In any case, it’s definitely big enough for a recent Science Magazine article to correctly use the term “Ratzilla”.
Ratzilla’s bite force was recently estimated up to 4000N, enough to outperform modern crocodiles and tigers. It was definitely a herbivore though, and is thought to have used its teeth as elephants use their tusks: to dig around for tasty treats.
Luckily for us, Ratzillas (Ratzillae?) no longer roam the plains of South America. They went extinct about 2 million years ago, after 2 million years of rodent dominance. Interestingly, that makes them the contemporaries of terror birds, sabre-toothed cats, and giant ground sloths. Their size and sharp teeth probably made them tough prey items.
Just like the R.O.U.Ses in the Princess Bride though, they were probably susceptible to fire jets and swords.
And with this rodent rant written, I promise to not write about any more Rodents of Unusual Size for the remainder of this ABCs series.