A cave dweller or caveman was a being inhabiting a cave. This was not uncommon in primitive cultures.

On ancient Earth, Troglodyte was a term for cave dwellers. (TOS: "The Cloud Minders")

The early Earth cartoon Daffy Duck and the Dinosaur showed a caveman and the cave in which he lived. (VOY: "Memorial")

After being stranded on Hanon IV, USS Voyager crewmembers speculated that its natives might be cave dwellers. (VOY: "Basics, Part I")

Upon studying an Iconian device recovered from Denius III, Donald Varley described his frustration at not understanding it by comparing him to a caveman confronted with a Tricorder. (TNG: "Contagion")

Two decades after Dramia II was first hit by an Dramia II plague, the once civilized planet again had cave dwellers. (TAS: "Albatross")

It seems Novans would also qualify as cave dwellers.