Barlowe Digmite
The Barlowe Digmite split from its ancestor and moved into Barlowe, populating and eventually crossing the desert. It has developed larger hind leg fins, which allow it to release excess heat in the desert. It is otherwise very similar to its ancestor, though during its journey through the desiccating desert it mineralized its eggshell and developed a new habit: digging with its butt.
As the gonopodium of Arthrotheres is formed from a fused pair of limbs, it is not unreasonable for a species to unfuse it. The Barlowe Digmite has done just that, regaining the superficial sideways beak-like appearance to the organ not seen since its distant barely-legged aquatic ancestors. This, in combination with added mobility and ridges along the outside, allows it to easily drive this organ into the ground to lay its eggs. Notably, because the unfusing of the gonopodium means its opening can stretch more, male and female Barlowe Digmites have much more similar-looking reproductive organs because the female can literally stretch hers open to receive the male. However, sexual dimorphism still exists, as the male’s gonopodium lacks the ridges that help the female drive hers into the ground.
The Barlowe Digmite’s eggshell is made of aragonite reinforced with chitin. Newborns usually eat their eggshell after hatching, which helps grant them the minerals needed for their endoskeleton to grow. Their exoskeleton, meanwhile, dries quickly after hatching, allowing them to immediately go out on a hunt for their first carcass to feed on. The mother will have usually laid her eggs near a carcass already, but if she hasn’t or if the carcass was already eaten by the time of hatching the newborns are capable of finding one on their own.
Like its ancestor, the Barlowe Digmite is highly aggressive and will kill other organisms similar to it in size. Females will even attempt to kill and eat males after mating, though occasionally the male will escape and live to mate again. The Barlowe Digmite is a burrower, but this is where subspecies are distinguished. I. a. deserta, residing in the Glicker-Barlowe Hot Desert, only burrows to sleep at night and avoid the heat of day, as the hot shifting sand is too unstable for it to form permanent burrows. The other subspecies, I. a. barlowensis, still constructs long winding tunnels like those of its ancestor. Both subspecies burrow using their antennae, though they may assist the efforts by furiously scrabbling with their forelegs.