The Ghorusdans were a species native to Ghorusda.
Ghorusdans have values that are very complex and differ greatly from Federation values; furthermore, they have a large number of cultural taboos.
When first contact was attempted with the species, the Federation sent a specialist, the Betazoid Tam Elbrun to handle the difficult situation. Elbrun got too involved with the Ghorusdans, however, and First Contact went fatally wrong, resulting in the death of 47 crewmembers of the USS Adelphi. This tragic incident was known as the Ghorusda Disaster from then on. (TNG: "Tin Man")