The Crocodiles of the Pleistocene
A few weeks ago Prehistoric Planet: Ice Age released to a overall positive reception, but alas, as so often the case, my favourite group of animals was shafted. But this won't stop me from providing an overview of what was around.
Let me prefice this by saying that I of course understand their absence, obviously more unique fauna takes priority and I don't begrudge the team their choice. I also want to highlight that I'm just pulling from the entire Pleistocene, rather than just the ice age proper.
Shout out to Joschua KnΓΌppe's fantastic "Giants Among Us" poster, featuring (most) Pleistocene fossil crocodiles Go buy it NOW
Lets start with one that's perhaps the least interesting but easiest to cast: Alligator hailensis. By all accounts, hailensis is not too different from modern gators, being closely related, similarily proportioned and reaching a similar length. Obviously that makes its inclusion the least vital but the easiest. Insert some shots of a modern gator (easy enough to come by) and just pretend its hailensis. Especially as filler along more exciting animals like short faced bears, Xenosmilus, sloths, elephants, etc...
And that's it for North America already. Turns out glaciation is not especially conductive for croc diversity. Thing's aren't looking much better for South America either. Joschua's poster features Caiman venezuelensis, found at the El Breal de Orocual tar pit. But the validity of this species has been questioned. It's known from fragmentary remains and may instead just be a spectacled caiman as we know them today. It does share some similarities with the Rio Apaporis caiman, which is a whole other can of worms (ignore the fraud in the photo).
On the note of C. venezuelensis, I'll also briefly bring up "Crocodylus caiari", which even I was unfamiliar with until earlier this year. Alas, tho a well preserved animal possibly close to modern Orinoco crocs, its a nomen nudum as its never been formally published.
To compensate for the lack of described and distinct fossil crocs from the Americas, I'll give a quick shout out to Cuban crocodiles, which used to be far more wide ranging during the Ice Age and would have come into contact with (and hunted) island ground sloths.
Turning attention towards Africa offers much better studied options. Two of the most well known are probably the Paleoafrican crocodiles of East Africa, Crocodylus thorbjarnarsoni and Crocodylus anthropophagus, both of which would have been in immediate contact with early humans. C. thorbjarnarsoni may have reached sizes larger than even the largest modern saltwater crocodiles. Brochu and Storrs even half jokingly suggest that the reason theres no direct evidence for human predation in Kenya is because it would just swallow early humans whole.
Further north then you would find Crocodylus sudani, perhaps a golden opportunity to address how the Sahara wasn't always an enormous desert. Anatomically this one is considerably smaller than our previous two mentions, but does combine a rostral boss with squamosal horns.
As far as the African mainland is concerned I saved best for last: Euthecodon This one might look like a gharial, but its actually a relic of a time when "dwarf crocodiles" were much more diverse. Long snouted with strange, sleeved teeth and oh yeah probably quite large.
Before moving on theres two more island species to cover. Over on the Seychelles there's Aldabrachampsus, a small species with cute little horns above the ears. It may have fed on or at least scavenged on the island's giant tortoises.
And if you like the "cat ears" then look no further than Voay over on Madagascar. The island is already featured so perhaps there was at one point discussion, but alas. Anyways, Voay is probably the most famous croc with enlarged horns and perhaps the one with the largest. Voay was the one I had more hope for than most the others and I do think it could still work with what we got, but theres a lot of other stuff they could have done with Madagascar, from giant lemurs to the various native hippos.
In Asia we're getting three for the price of one with Toyotamaphimeia and Hanyusuchus, the former featuring two species native to Japan and Taiwan respectively while Hanyusuchus inhabited the Chinese south-east until the 14th century. I will concede that Hanyusuchus is probably most interesting in its recent history and its relationship with advanced human civilisations, while Toyotamaphimeia taiwanicus is rather incomplete.
Toyotampahimeia machikanensis from Japan meanwhile is ideal. 6 to 7 meters long, quite robust, its close kin are interpreted as possibly having been quite vocal and capable of taking down horses and other livestock. It lived at the edge of what crocs can tolerate in terms of cold, shows evidence of fighting others of its kind, etc...
If we wanna talk more generalized crocs we got Crocodylus palaeindicus, close kin to today's Mugger crocodiles, in India and the contentious Crocodylus ossifragus, perhaps a synonym of the Siamese crocodile. Alas I gotta read more into them so apologies for the bare bones summary.
An animal I am more familiar with is the Mun River Alligator, Alligator munensis. It is one of the two alligators from Pleistocene Asia (alongside the still living Chinese Alligator), but easily recognized by its deep, body skull that may suggest it fed on hard-shelled prey.
Another one from South Asia is Gavialis bengawanicus. Unlike Toyotamaphimea and co. this one is in the same genus as todays Indian Gharials and therefore a great deal more gracile, with large, telescoped eyes.
Continuing this southward trajectory takes us to our second to last gharial for this thread, and one of the most interesting ones. Ikanogavialis (?) papuensis inhabited the coast of the Salomon Islands of New Guinea and would therefore have inhabited saltwater. It was described as a species of Gavialis then attributed to Ikanogavialis. Problem is that geographically and stratigraphically, Ikanogavialis is rather distant. Then again, PhP does not concern itself with genus names that much and Papua gharial would actually work just fine. It's also been argued that the holotype is nondiagnostic on a species level and could still be Gavialis, but perhaps additional remains and studies can clarify things beyond the fact that it existed.
Instead, lets turn to our last gavialoid over on the Australian mainland: Gunggamarandu. Now two big caveats 1. it's not known from the most complete material 2. it's not entirely clear whether or not it was Pliocene or Pleistocene, like another croc later on
What Gunggamarandu would offer is a unique branch of gavialoid on continental Australia. Phylogenies suggest it may have been a very early branch and gharials are an underappreciated part of Cenozoic Australian croc fauna, otherwise dominated by the next few taxa.
We've finally arrived at mekosuchines, a unique radiation exclusive to Australia and some islands. First lets talk about Paludirex, the swamp king. There are two species to be considered, the smaller Paludirex gracilis which was definitely Pleistocene. And the larger, more robust Paludirex vincenti, although much like Gunggamarandu its not entirely clear whether or not it actually reached into the Pleistocene or died during the Pliocene. For entertainment value tho I would have loved to see it featured.
Of course we can't talk mekosuchines without mentioning Quinkana, a mysterious animal with a deep skull and serrated teeth often interpreted to have been terrestrial. Sadly, while I would have loved to see it, the lack of remains means its at a high risk to age badly.
Theres at least two more mainland mekosuchines I at least want to mention, the Darling Downs taxon and the Floraville taxon. The former may represent a third species of Paludirex, while the latter is a ziphodont form, possibly distinct from Quinkana.
Which takes us to some of the last holdouts of mekosuchines. Over on Fiji there was Volia, an animal some 2 or 3 meters in length. It's remains are fragmentary, but show an animal with at least somewhat elongated jaws that likely filled the niche of top predator.
Finally, there is the iconic Mekosuchus, known from two species from New Caledonia and Vanuatu. Contrary to popular belief, its not that likely that they were tree climbers and instead their teeth suggest adaptations to feeding on hard shelled prey like crabs and snails.
Now as I said at the beginning of the post, I don't blame anyone on the lack of crocs. As has been said in the aftermath of the first two seasons, when you got the choice between something clearly unique vs a croc with small horns, its obvious where the budget goes. But I do believe that there are a handful that could have been nice additions for their ecological impact or their anatomy. Still second fiddle but unique in their own right. I also do think that theres a handful of forms that could have been aluded to via stock footage and only IDd via narration, tho of course we all know that animal IDs in season 3 are their own can of worms but I digress, the main point of the thread is not a critique, but a love letter to the crocs that were knocking around at the time in addition to the ones still with us.
And of course theres still plenty of cool things that can be done with crocs regardless, even as a simple secondary antagonistic force to the protagonist animal of whatever segment.
