Rockshorian

The rockshorian has split from its ancestor, specializing as a piscivore and spreading along the coasts of the Dixon peninsula, where it stands still over the water waiting, pretending to be a rock. The shell-like extension of the sauce has taken a rock like shape externally, growing layer by layer with tiny gaps in between from the inside out, letting erosion and cracks form on the surface and result in a rocky surface. Likewise the tail plate has evolved to complete the camouflage with a rocky club. The raised spiracles have flattened laterally, creating a fan shape that allows the spiracles to be raised between the rocky shell and tail club with minimum disturbance to the illusion.

Adapting to handle the heavy salt content of its diet, the kidney equivalent within its digestive system has evolved to excrete salt in large quantities, even allowing it to quench it's thirst with saltwater. It is stockier overall, with a relatively shorter tail and most its weight placed directly over the legs, but its neck is longer, allowing it to catch prey out of the water and even raise its head to sniff around for danger without moving its body. A series of flexer tendons extend between the bones, allowing them to stay still for hours while exherting minimal effort, turning their waiting pose into a resting pose. Its feather whiskers touch the water waiting for any sign of motion, and concentrations of facial muscles around its mouth allow it to suck in and temporarily hold onto water without oral respiration, thus not losing their prey.

Rather than building nests, the female's shell curves inwards along the edges, where she will spit out a sticky mucus and stick her eggs, using her lips and long neck to capture each egg directly from her cloaca. Juveniles hatch with claws to hang to the feathery lining of the shell, and the exoskeleton covering of the palm of the claw has grown to create an opposable thumb for the claws to close onto. She will place food on the inner curve of the shell for her larva, and older juveniles will use it as a deck from which to start practicing and seeking prey from the water themselves.

Rockshorians live in outcrops of 6 to 12 adult females and their juveniles. Losing their nomadic lifestyle has come with a cost of genetic diversity and intermingling, so to avoid inbreeding, males reaching puberty will be expelled from the outcrop to roam as bulls, competing with other males through tail bashing and seeking female outcrops to breed with. While they do have a sturdier shell and slightly longer tails, most males die due to predation before getting to compete, so the sex dimorphic pressure isn't very strong.