Prometheans are a species of vaguely theropodian sophonts native to the planet Prometheus in the Proxima Centauri system. Their biochemical basis is radically different from any other sophont species in known space, and thus are not fully integrated into the USSC (though they are allied.)


Prometheans, like the rest of Prometheus’ biosphere, have biochemical structures based on both carbon and silicon that allow them to thrive in the terrestrially uninhabitable environment of their frigid homeworld.  

Anatomy & Morphology

Prometheans are horizontal bipedal hexapods with an inherently bifurcated limb structure; the lower portion of each single limb has two separate branches. The forelimbs at the front of the torso are manipulatory in nature, followed by their locomotive midlimbs (with lower branches fused) and fin-like hindlimbs used for balance and steering. The torso itself transitions to a narrow, fluke-like tail held high above the rest of the body as a counterweight and aerodynamic control surface.

The Promethean skeletal system is composed of a substance nearly identical to fibreglass, being a tough carbon polymer reinforced with quartz fibres. Their vascular oxygen carrier is haemiridin, a highly complex iridium-based protein that, while canary yellow in its deoxygenated state, turns a dull orange when oxidized. Though efficient, haemiridin is highly photosensitive, causing the Promethean vascular system to be completely opaque in most places.

Prometheans have a dorsal mane of hairlike silicate fibres running from the tip of their head to the base of the first shoulders, illuminated in a fibre-optic-like manner by bioluminescent skin patches to mimic the flora of their homeworld. Similarly, their tails have an individually-unique pattern of heat-radiating splotches to help pod members identify each other.

Perception & Sensory Capabilities


Like most of the Promethean biosphere, Prometheans' vision is based mainly in the infrared spectrum, with some visible red. To detect this, Prometheans have a short series of sensory pits on either side of the head, just behind the biosonar arch.  


Promethean sensory processing is largely based on hyper-fine sonic ranging; useful for organisms living in the dim glow of a red dwarf sun. Their primary sense is biosonar, facilitated by a complex hydrostatic organ not unlike those of Earth's dolphins. Prometheans use different sonic frequencies for different purposes; lower ultrasound frequencies (20-40 kHz) are used to communicate linguistically, while higher frequencies (40-80 kHz) are used for echolocation.  


Promethean olfactory sense is extraordinarily sensitive as well, facilitated by a pair of long, dexterous tentacle-like appendages that protrude from the skull just below the infrared pits. These antennae each sprout a long, thin line of fine silicate fibres that comb the air for scents.  


The Promethean tactile sense is moderately strong. Their entire epidermis is sensitive to tactile input, though the effect is most intense in the manipulative structures at the ends of the upper limbs and the olfactory antennae.


Geographic Origin & Distribution

Prometheans are quite an uncommon sight across known space, as planetary environments that mirror their homeworld Prometheus are sporadic in the local interstellar group. The planets they have managed to settle are few and far between, thus the likeliest place to meet a Promethean is at an interstellar hub station on one of their intercolonial routes.

Habitat & Survival Factors

The optimal survival range in a variety of factors for an unequipped Promethean is actually somewhat narrow given their unique biochemistry, and while specialized habitats and equipment can allow them to directly interact with other spacefaring species, they typically prefer to keep to their own kind.
Scientific Name
Tesserachira sapiens
Average Height
3 meters
Average Weight
120 kilograms
Biotype biochemical multicellular
Biochemical base carbon/silicon
Solvent CH4
Respiration compounds N2
Physiotype horizontal bilaterally symmetric hexapod (endoskeletal caudal)
Sapience type hemifocal centric
Homeworld Prometheus
Home system Proxima Centauri
Contact date 12083 UME
Tech level 12.5

Interspecies Relations

Shortly after first contact between humans and Prometheans, the two species formed an agreement of interstellar cohabitance called the Proxima Accords, which grant the Prometheans exclusive first claim to any Prometheus-like worlds discovered by most species. The Accords have been expanded over the centuries to include new USSC members; however, the rimor refuse to sign the Proxima Accords, breeding slight contention between themselves and the Prometheans.


Please Login in order to comment!