Baru: The Cleaver-Headed Crocodile
Ok back on my croc stuff, today discussing Baru. Like most the other crocs I've been talking about, Baru was a mekosuchine, a member of an endemic radiation of crocodilian native to Australasia.
Baru is easily among the largest of this group and among the most robust, with massive curved teeth and almost inflated looking jaws.
Left my interpretation of Baru darrowi, right the illustration by Willis et al. from 1990.
My reconstruction differs subtly in some regards, obviously the jaw material shown is from Ristevski et al. 2023 and elements of the posterior skull are based on the older Baru wickeni. My mandible also turned out slightly different, tho the quality of the images in the original description is not great so that is not guaranteed.
Anyhow, this head likely sat atop the body of what was a decently large crocodilian, with estimates suggesting four or even five meters in length for both currently recognized species Baru wickeni and Baru darrowi. As you can see below, I went for the lower estimate (which is the one given by proper publications), which still renders an immense animal all things considered, certainly holding up with many crocs of today.
Currently, there's two recognized species, one unnamed species and one that has been reassigned. The older of the named species is Baru wickeni, which was found in the Lake Eyre Basin and Riversleigh World Heritage Area during the late Oligocene. Like I already said, it was approximately as large and robust as the later Baru darrowi, but did differ in some regards. The skull had much more prominent crests, the nasal bone extended into the opening for the nares and importantly, the cutting edges of the teeth were smooth.
During the Miocene, Baru wickeni would be replaced by Baru darrowi, known from younger strata of the Riversleigh and the Bullock Creek fauna. Baru darrowi had less prominent crests, but in turn slight serrations on its teeth. Also the nasal bones did not extend into the nares. Baru darrowi is the species shown at the start.
The other two are then the unnamed Baru species from the Alcoota fossil site and "Baru" huberi. I talked about the latter before and how it is now thought to be something else entirely. Which leaves us with the Alcoota form. Generally regarded as a distinct species, fossils of the Alcoota Baru have been found from 2000 onwards near Alice Springs and appear to represent an animal more robust than the other known Baru. Below you can see a skeletal mount on exhibition at the Megafauna Central in Alice Springs (image by Aussie Bucket List) and a skull held by Adam Yates, an important researcher of this animal.
A little side note I want to mention is the name Baru. As you might have guessed from the etymology of various other mekosuchines (Kambara, Mekosuchus, Quinkana, Kalthifrons), the name actually ties into the native People of Australia. Specifically, Baru is a figure in the mythology of the East Arnhem Region, which describes him as a sort of totem crocodile that brought law to the lands he named. Baru also had a fight with Jarkitj (Willy Wagtail) after stealing fire for himself. Sadly I couldn't find much about the mythical Baru beyond a brief summary written up by George Pascoe Gaymarani you can read here.
Returning to the animal, one would suspect that the robust skull meant that it didn't quite hunt like modern crocodiles, especially considering the serrated teeth found in the younger species. Well, tho nothing concrete is known Willis and colleagues speculate that this might have been an adaptation to shallower waters. While modern crocs tend to ambush prey, grab it using a strong bite and conical teeth and then proceed to drown it, Baru may not have had that option. A modern croc can just drag a zebra for instance into deep water, weaken it and let go to adjust its grip without the risk of it getting away. In shallow waters, this may have been too risky and lead to prey escaping. So Baru's robust head and curved, sometimes serrated teeth were built to inflict a lot of damage upon prey when lunging, securing the bite and incapacitating it. Willis estimates that it may have taken prey as heavy as 300 kilos.
There's also the interesting tidbit of Baru wickeni coexisting with a diverse croc fauna, yet being conspicuously absent from more southern regions of Australia despite entering the respective drainage basin. I go into more detail while talking about Australosuchus, but the jist of it is that Baru was likely not as cold resistant as Australosuchus and thus not found as far north.
Alas, as with other mekosuchines, not much art of Baru exists aside from this absolutely fantastic piece by @knuppitalism-with-ue
As per usual, this deep dive is brought to you as part of me redoing the wikipedia page of this genus, which resulted in a major size increase. The image below is just to show the difference, but if you want to read it here's the link: Baru - Wikipedia