A curiosity even on an island of curiosities, the scissor-head is quite possibly the strangest predator on the island. Actually a variety of pterosaur, the species has given up flight entirely, becoming bipedal, specializing to an extreme. Slender and stilt-legged, it has an oversized, scissor-like head with interlocking rows of fine, comb-like teeth. The legs are oddly proportioned, with long shins that elevate the creature above the streams where it hunts bony fish with its unusual head. The forelimbs have evolved into tiny flipper-like appendages, while the tail is shortened and stiff.
The functions of these bizarre characteristics become clear when the reptile enters the water. Living in fast-running streams, the scissor-head prowls the shallows like a heron but can also hold its breath and dive beneath the water to chase down prey along the bottom. Specialized organs in the body and tail allow the animal to maintain neutral buoyancy while its streamlined shape affords it speed and grace underwater. Propelled along the stony bottom by its long legs, scissor-heads can chase down bony fish. It can use its long snout to retrieve aquatic invertebrates hiding under stones on the bottom.
Sphincter nostrils, high on the head, permit it to quickly take in air on the surface and seal the airways tightly before diving, cormorant-like, and continuing to hunt along the streambed. A scissor-head is able to hold its breath for several minutes below water. In the cool water, blood can be drawn from the outside surfaces of its body to retain heat, extending its hunting periods.