Remember my post from last year about azendohsaurs and trilophosaurs? Well just the other day, paleoartist extraordinaire Gabriel Ugueto posted a sketch of something called Teraterpeton. I had no idea what this zany-looking reptile was, so I looked it up and was flabbergasted to find that it's a trilophosaur that is quite unlike Trilophosaurus. You'll notice that I did mention Teraterpeton in passing in that post, which must mean I didn't think it was a trilophosaur or at least was not unambiguously a trilophosaur. Turns out I'm incorrect--Teraterpeton is a perfectly good trilophosaur, and therefore an allokotosaur!
|A drawing of the header image from Sues (2003).|
In fact, that's probably not the case. Trilophosaurus lacks an antorbital fenestrae, as do the closely-related azendohsaurs. Sues initially believed the large opening to be an antorbital fenestra but, given what bones it's bordered by, "the opening most likely represents a greatly enlarged external narial fenestrae." Indeed, the premaxillae are extremely long and the nasals have been reduced to oddly-shaped bones that have been shoved backwards toward the skull roof. Behind them, the prefrontals form small lateral flanges overhanging the orbits.
The rest of the skeleton is mostly unremarkable although the incomplete right manus has distinctive claws: they are tall but narrow and "blade-like." This is also a major difference from Trilophosaurus, who has slender fingers and relatively small claws. Trilophosaurus is usually considered arboreal, but what was Teraterpeton doing?
|The intimidating claws of Teraterpeton|
It was almost certainly not arboreal, but the large claws; long, toothless snout; and closely-packed occluding teeth remind me of burrowing insectivores like aardvarks and armadillos who slurp up bugs and grubs with a long tongue and crunch them up with strong molars. Note that this is not the same as specializing for eating eusocial insects like termites or ants: in those animals, dentition is typically reduced in size or lost entirely. For example, anteaters are completely toothless and aardwolves have extremely small molars.
I'm coming around to the idea that Teraterpeton was the Late Triassic equivalent of the aardvark. But this also speaks to the great morphological distance between Teraterpeton, a burrowing aardvark-like animal, and Trilophosaurus, an arboreal iguana-like animal. It makes me think that the Trilophosauridae is far more diverse than we currently know, which is an exciting thought!
|An adorable aardvark emerging from its burrow, from Wikipedia.|