Spindle

The Spindle are, or were, the dominant race in the Universe before the advent of humanity. They died of culture shock on discovering a race called the Wheelers had preceded them.

The Spindle evolved on a low-gravity world: mummified Spindle corpses discovered aboard a derelict spacecraft point to a race three feet tall, long-snouted, double-thumbed, and with legs alternately banded in blue and orange. It appears their whole body could act as a brain. They were telepathic and claustrophobic: no more than a thousand could bear to inhabit the same world or it would have become overcrowded and unbearable.

For a crew of three Spindles, the spacecraft needed to be a hundred miles long... however, the recovered wreck contained the secret of the Strata-machine as well as other goodies that when retro-engineered, provided secrets that enabled the human race to progress to a new stage in its development.

Annotation

Again this echoes a concept from Douglas Adams' Hitch-hiker's Guide to the Galaxy. Adams creates a race of evolved, serene, beings whose maturity and gentleness so gets up the nose of the rest of the Galaxy that they are inflicted with the worst social disease of all - telepathy. Either they have to block out the telepathic messages by constantly talking to each other, or their home planet Kakrafoon has to play host to the loudest and most destructive plutonium rock band ever, Disaster Area. Again, you wonder about cross-fertilization of ideas - Pratchett taking what was only ever a single throwaway joke in h2g2, and expanding it a little further to see where it led.