Euryptis

Euryptis is a genus of long-jawed, parthenogenic Figera species sporting large mandibles, fins, and a hard exoskeleton. While individual shapes/sizes differ between species, each is characterized by a front-facing excretion hole and an appearance similar to Terran eurypterids.

Hard-shelled Nepa
(Euryptis testa)

The Hard-shelled Nepa, Euryptis testa, is a large carnivorous species of nepa typically residing in shallow tropical oceans. They are especially notable for sharing evolutionary ties to early invertebrate species, suggesting the development of vertebrae across the evolutionary line. They are immediately recognizable by their splotchy eyes, long and jagged jaw, hard exoskeleton, and front-facing excretion hole. This excretion hole functions just as all other Xi'ialoan organisms' holes function, releasing waste after nutrients have been absorbed. However, nepa species lack digestive enzymes in their stomachs that are key to the breaking down of biomatter. Instead, their stomachs serve more as interior "holding chambers" for ingested food. Excrement, however, undergoes reactions facilitated by the interior circulatory system that result in digestive enzymes forming once the waste is ready to be released. This process, paired with a front-facing excretion hole, makes for a devastating form of attack. Gliding across the ocean floor, these creatures hunt primarily by movement, running their mandibles over the ground beneath their bodies. Once movement is detected, their mandibles lock onto the prey item, preventing escape while excrement is released onto the organism. After this excrement has been released, their exterior jaw and esophagus work to carry the prey into the stomach chamber, where the enzymes in the excrement work to digest nutritious biomatter before the process begins again. They typically grow to around 8 ft (2.4 m) long and typically weigh around 70 lbs (31.75 kg).Â