When the USS Enterprise was exploring this quadrant, the starship picked up a distress call coming from this a city on this planet. A landing party discovered that the world was barren. There were no apparent animal lifeforms and sparse vegetation. According to the distress call, there were 900,000 Scalosians who lived in a nation; 113,000 of them in one city. Their civilization was rated 7 on the industrial scale.
After the world was devastated by volcanic eruptions that contaminated the water with radiation, the Scalosians changed. They were hyper accelerated. The children died, with many females being unable of carrying children and the men were sterile. Desperate, the Scalosians looked for mates outside their world. When a spaceship passed by, a distress call was sent and, when the ship came in to investigate, the crew were captured. After being hyper-accelerated, they did not last long, so the Scalosians waited for the next ship as their population plummeted.
When the planet was visited by the Starfleet vessel USS Enterprise in 2268, only five hyper-accelerated individuals remained. After the Enterprise visited the planet, the Federation quarantined the planet. (TOS: "Wink of an Eye")