Golgafrinchan

Golgafrinchans are a sapient humanoid species from the planet Golgafrincham, which colonized Earth two million years ago. They're believed to be the ancestors of Humanity.

Biology
Golgafrinchans are externally identical to Humans, and are presumably identical or extremely close to Humans in terms of internal physiology.

Culture and society
Golgafrinchan civilization was divided into three social groups: one consisting of leaders, scientists and artists; another consisting of menial workers; and a third group considered largely "useless" by the other two. This middle class included non-essential professions such as telephone sanitizers, hairdressers, advertising account executives, used car salesmen, TV producers, etc.

At some point, the Golgafrinchans decided to get rid of their "useless" middle class and fabricated a story about their planet being in immediate danger. Different versions of this story existed, some possibly involving the planet crashing into the sun, being invaded by giant piranha bees, or devoured by a mutant star goat.

The Golgafrincham Ark Fleet Ship B was constructed to transport 15 million middle class Golgafrinchans to another planet, unaware that the other two classes were staying behind. The ark ship eventually crashed on Earth and colonized it, while those who stayed behind on Golgafrincham ended up being killed by a virulent disease contracted from a dirty telephone.

Appearances

 * The Restaurant at the End of the Universe, by Douglas Adams (1980)