Species 10-C
Species 10-C or 10-C, originally classified by Starfleet as Unknown Species 10-C in 3190, were a highly advanced non-humanoid species which created the Dark Matter Anomaly (DMA).

History
The Species 10-C homeworld was a gas giant planet in a star system just outside of the Milky Way Galaxy's galactic barrier.

At some point prior to the late 22nd century, the 10-C reached such a level of technological advancement that they were able to construct Dyson rings around their star. However, around the late 22nd century, their homeworld was rendered uninhabitable to them as a result of cataclysmic meteor impacts. Some members of Species 10-C were able to evacuate, but many were stranded on their planet and killed. By 3190, the 10-C had created a hyperfield that served to protect their new home from danger. This hyperfield required boronite to be powered, which was harvested through the use of the DMA.

The 10-C became known to the Federation in 3190 when the DMA began destroying numerous star systems, which the Federation eventually realized was a method of mining boronite. At first, it was believed that the DMA was a natural phenomenon, but after further study it was determined to have been artificially created. Federation Security provisionally named the race behind the DMA's creation Unknown Species 10-C and speculated that this race may have been the Metrons, Nacene, the , or survivors from the Iconian Empire. () It was later determined that Species 10-C was extra-galactic in origin, ruling out some of the aforementioned species as possibilities, and after first contact was made, it was discovered that the 10-C were a previously unknown species and not any of the possible races listed by Federation Security. ()

Later, Zora was able to determine the point that the DMA entered the galaxy, which was possibly the location of Species 10-C. () Upon investigating that region, the  found a void absent of black body radiation large enough to hold a small star system. Based on this, sensor logs were analyzed and showed that Species 10-C were using the DMA to mine boronite. ()

Physiology

On an away mission to the Species 10-C homeworld, Doctor Hugh Culber deduced from fossilized skeletal remains that the Species 10-C were extremely large compared to humanoids, and appeared to have been "perfectly adapted for floating in gas layers" in the atmosphere of a gas giant. The bones had notably low density, and were flexible like cartilage. ()

After initiating first contact, Doctor Hirai scanned a member of Species 10-C and determined that they have visual receptors, pheromone glands, and that they may possess auditory or electrical sensors. The 10-C used these pheromone glands and light emissions/visual receptors to communicate with each other. ()

Culture
The 10-C may have taken special care to protect their offspring, as evidenced by the ruins of a large structure that may have been used as a nursery and as a protected area for infants on their original homeworld. ()

Unlike many of the sentient species native to the Milky Way Galaxy, the 10-C did not have a spoken language. Instead, their language was formed by emitting emotion-conveying hydrocarbons, as well as flashing lights on their bodies to communicate how the hydrocarbons should be understood. () 

Lifeform classifications
Unnamed species