Hadesians

The Hadesians was a sentient race that inhabited the Hades System until about 300,000 years ago. It is theorized that they destroyed themselves in a civil war. Long before any other known race, they accomplished spaceflight and settled on Hades I, Hades II, Hades III and Hades IV.

However, this race wasn't able to expand into other systems before their annihilation. They also hadn't discovered any jump point before.

The settlements on Hades I, II, are now ruined and their atmospheres are in a state of nuclear winter. Hades IV was literally split by an unknown weapon of mass destruction.

According to the writers, the species is completly extinguished.

Appearance
Hadesians were roundish, seven to eight feet tall. Their bulky central body had multiple thin appendages and a pair of long arms.