Sagmalix
The Sagmalix split from its ancestor and eliminated its ties to water, becoming fully terrestrial. It did not make its babies significantly better at walking on land, nor did it find some way to take the water with it; rather, its babies have only lost their gills, and it developed its parental care instinct to where it could simply carry its babies around—on its back.
The Sagmalix has developed its ancestral keratinous skin into a series of keratin plates—scales. The scales over most of the body are medium-sized and the size decreases on smaller body parts such as the face and digits. However, towards the top of its back, many are bigger, leading up to a giant saddle-like scale on its upper back. This saddle scale is present in both males and females, and during mating season the skin under the large scales surrounding the saddle will flush with blood to turn them a vivid magenta color. When a pair have babies, they place them onto the saddle so that they can carry them around until their limbs develop enough that they can walk on their own. In addition to the scales, the Sagmalix has also developed keratinous claws that serve to increase traction on land.
The Sagmalix has a variety of adaptations connected to its new method of parental care, as well as to being able to move more easily on land. Its legs have rotated at the hips so that its feet face more forwards, allowing it to leap like a terran frog. This is smoother and more stable than what it was doing before, preventing it from accidentally throwing its babies off its back and making its locomotion more energy efficient. Its pelvic ring is also warped to place the raptorial limb much further in front of its legs, therefore allowing it to land on its raptorial limb at the end of a leap. Modified clavicle-like ribs alongside the raptorial scapular ribs support the raptorial limb so that it isn’t dislocated from being used like this repeatedly. Further ribs fit along the pelvic ring so that even in the event of the clavicle ribs being broken, an impact won’t just drive the jutting part of the pelvic ring into the Sagmalix's organ-filled body. All of this stabilizes the part of its back which contains the saddle scale even more, making for a relatively smooth ride for its babies. The changes to its limbs also now make it able to walk short distances on two legs where hopping would be overkill, making it a facultative biped.
Ecologically, the Sagmalix is a small omnivore. It primarily uses its lateral mandibles for prey capture and to pull food into its mouth to process. Its brown coloration helps it to blend in with soil and leaf litter. It mates in either the spring or early wet season depending on where it lives within its range.
To reduce the strain involved in having babies, the Sagmalix has moved its cloaca to the base of the anal arm, effectively turning the anal arm into a tail. Because of this, mating has also changed; instead of holding hands, the male mounts the female and curves his anal arm under hers, performing a cloacal kiss. This change makes the anal arm far more useful as a sensory and manipulatory appendage, as injury to it no longer means injury to the ability to mate. The change had another, more bizarre effect, however. While millions of years of natural selection had put safeguards in place against any radial part of the head reduplicating, no such protection had evolved for the limbs because such mutations were usually fatal long before birth and therefore wasted far fewer resources. With the previous removal of most organs from the anal arm and now the movement of the cloaca far closer to the pelvic ring, however, it is now possible for a non-fatal mutation to occur which grants a given Sagmalix an extra anal arm. This mutation is rare and offers little advantage, and “twin-tailed” males usually struggle to mate successfully, but its sudden appearance is notable enough for mention anyway. Like its ancestor, the Sagmalix gives live birth to pseudo-radial babies.