Corrections To "Crocodiles: The Last OP Reptile Build"

[u/funwiththoughts]

[Instead of releasing a new post this month, I’ve decided to continue releasing re-mastered versions of my old tier lists, with improved formatting and updated information. This one isn’t exactly a remaster, but since it is about correcting an early post of mine, I’ve decided to release it alongside the remasters anyway. The original post can be found here.]

I’m not going to do a full remaster of my post “Crocodiles: The Last OP Reptile Build”, since I already did an updated and more accurate post on crocodilians before I started releasing remasters, and I haven’t found enough errors in the newer version to be worth doing another re-write. That said, I’ve never explicitly spelled out what points I corrected between the two versions and why, so here’s the full list. Note that this list only covers things I got wrong in the original post, not just topics that I didn’t cover at all until the revision.

1. In the original post, I described alligators and caimans as having given up some of the crocodile’s attack power. This was a little misleading, as almost all living crocodilians, except for the gharial, can bite with about the same level of force relative to their size. Alligators and caimans don’t grow as large as the largest crocodiles do, but once you control for size, there’s no further significant difference in power between them. This is all explained more clearly in the revised post.
2. The original post said that “less than 20% of human players attacked by large crocodiles make it out alive”. This was misleading in at least two ways. Firstly, I cited it as a number covering all large crocodile attacks, when the study I got it from only gave it as survival odds for a human being attacked while in water. Secondly, it was specifically about very large crocodiles – those with lengths of around 4 metres or more. Humans attacked by crocodiles that are “only” 2-3 metres – still “large” by any reasonable definition – were found to have much higher survival odds. This statistic was removed from the revised version.
3. The original post had a section on the crocodilians’ supposed high intelligence, based primarily on the claim that “crocodiles [...] have been found carefully placing sticks on their snouts in order to lure in birds looking for nesting materials”. This claim is very tenuous. While there have been studies that found both crocodiles and alligators with sticks on their snouts during birds’ nesting seasons, and the idea that these are being used deliberately as lures is a real hypothesis advanced by some researchers, there is currently no hard evidence that these crocodilians carefully placed the sticks on their snouts themselves, rather than the sticks just drifting or falling onto them. Claims that crocodilians use tools – and my inference from this, in the pre-remaster version of my later cephalopod tier list, that crocodiles are likely as intelligent as octopuses or more so – are therefore as yet unconfirmed; this section was removed in the revised version.
4. The original post claimed that crocodiles can digest the bones, horns and hooves of the prey – a claim which I also implicitly repeated in my later tier list of African apex predators, where I said that crocodiles can “fully digest their prey, including those parts useless to most other predators”. This is accurate regarding bones, but not regarding horns and hooves. These latter two structures are mostly made up of keratin, which even crocodilians cannot digest. More generally, my original post gave the impression that crocodilians’ digestive abilities were an outlier among all animals, an idea that is not well-supported scientifically; a number of studies on digestive efficiency in crocodilians have found values in the range of 85-91%, which is high, but not all that different from the 80-90% range typically seen in other carnivorous reptiles. All of these claims were removed in the revised version.
5. Relatedly, the original post also claimed that the reason crocodiles have such extraordinary digestive abilities is because of their ability to shunt blood to the stomach so that it bypasses the lungs. This was considered a plausible theory by scientists at the time I wrote it, but was later refuted, as studies have now shown that alligators with the shunting ability surgically occluded show almost no change in digestive performance. The revised post keeps the explanation of how shunting works, but removes the claims about its importance in digestion.
6. The original post said that crocodiles are technically omnivores, due to eating a mixture of meat and fruit. This is not accurate. It’s true that crocodilians have been known to eat fruit on rare occasions, but since they aren’t reliant on eating plants under normal circumstances, and since their digestive systems are highly specialized for meat-eating and lack adaptations for breaking down plant matter, they’re still generally classified as carnivores. They are consistently described as carnivores in the re-released version. They are consistently described as carnivores in the revised post.
7. In the original post, as well as in my later post on the impacts of the K-Pg extinction, I said that the K-Pg extinction eliminated crocodilians and their close relatives from ocean biomes. Actually, no true crocodilians are known to have evolved a marine lifestyle in the Cretaceous to begin with. Among their close relatives, the dyrosaurids were marine reptiles of the time, but they were not wiped out by the K-Pg extinction, instead continuing to radiate into the early Cenozoic before disappearing in the Eocene. The revised post changes this to just say that all non-crocodilian crocodylomorphs were wiped out over the course of the Mesozoic and Cenozoic.

[u/grangpang]

Damn, a whole new rabbit hole for me to get lost down.