Hydramendax tricephalus is a large Late Triassic drepanosaur, around 1m long (~3’3″). Related to fossorial forms like Skybalonyx, it digs underground burrows using the massive singular claws on its hands — which are specialized to the point of having fully lost all the other digits — and spends its time on the ground rather than climbing around in trees.
No longer used for grip while climbing, its prehensile tail-claw has been repurposed as a “false head“, enlarged and vividly colored to startle and distract predators. A single Mirasaura-like crest plume with similar bold eyespot markings appears to serve as another decoy head, and also as a visual display structure, able to be raised and lowered atop its shoulder hump.
It primarily feeds on insects, using its claws to rip open rotting wood and its long birdlike jaws to probe inside — but it’s somewhat more omnivorous than its relatives and also eats roots and tubers unearthed while burrowing.