18-Scorpii-4 Fauna: Basal Hexapods

The hexapods of 18Scorpii constitute the dominant and most diverse group of macrofauna on Earth. Their origins are unclear, but it appears that one of the oldest groups of hexapods still exists. And like Earth's monotremes, these survivors seem to have developed a very particular anatomy.
This group has been aptly codenamed, using the already strange animals on Earth: its codename is MCX, for "Monotremata-Curculionidae-Xenarthra."
These animals are quite recognizable due to their singular appearance. Their head (reminiscent of weevils or echidnas) is rounded, but also extended by a kind of long rostrum, at the end of which is a tapered, serrated mouth. Their nasal antennae are very long and angled like those of certain ants or beetles. Their forelegs are often larger than their two hind legs, bearing large claws (similar to those of anteaters or armadillos). But the strangest feature is their back: a bulbous mass composed of a thick, semi-porous carapace made of a mixt of chitin and calcium!
This distinctive dorsal carapace has earned them the nickname "Rockback," because in addition to having a back resembling a large rock, they use it as if it were one. These animals are primarily nocturnal, and to protect themselves from predators, they bury themselves in the ground, leaving only their backs exposed, like a rock emerging from the earth. Unintentionally enhancing this camouflage, certain plants and mosses find a way to grow on the support provided by this dome. This camouflage, combined with their armor being stronger than any other animal on the planet, gives them the advantage of having no predators once they reach adulthood.