El-Aurians

In 2473, a ship was discovered in difficulty with on board 75 El-Aurians. They were happily welcomed on Terra Nova. Also, they are compatible genetically with many other races, Humans, Klingons, Vulcans, Betazoid, and others.
Planet : Geologically, the planet evolved much like Earth did, with lushes forest and plentiful oceans. Now, there’s nothing left of the beautiful planet, the Borg took everything away.
History : When we could say that the first civilization were starting on earth, the El-Aurians had took their first step in space. By the time that we reach the 19th century, they were capable of space travel through out the galaxies, just like us right now in the 24th century.
They encounter the Borg around the beginning of the 22nd century. At first, they didn’t seem interested by the El-Aurians but it all changed at the second half of the century. The El-Aurians fled their home world and disperse through out the galaxies. In 2293, a first contact was establish with the federation, when a group of refugees, cut up in the gravitational pull of a nexus asked for help (Episode ST Generation). Some of those people decided to stay on earth.
To be noted, they knew about the existence of Earth but found the people to be backward, truth that it was around the 19th century and the United States had just come out from civil war, and the mentalities were less then open about other races, (Episode with Guinan).
They don’t mingle mush with the federation, but we can find them at position like Counsellors, or in other capacities as civilians bar keeper, hair dresser, places where their skills of listening sometimes help others deal with life’s problems.
Physically : The El Aurians are almost identical to Humans, even down to the gender and ethnic groupings. They have a far longer life span than Humans, but just how long they live is unclear. (Guinan is approximately over 500 years old.) Some developed a heightened sense of time and space as a result, although details of this ability are not clear, it could be a general biological aspect of their species. 
Custom , traditional, religion, etc : El Aurians pride themselves on being a race of listeners, and appear to have a form of limited empathic ability. Some have used this to help others, acting as advisors or confidants. A few have turned their talent to more dubious pursuits, becoming con men and tricksters. What is less known are the deeper elements that makes an El-Aurian.
Most of the heritage, paintings, music and written nearly all disappeared during their escapes. Some still subside and some El-Aurians accepted to talk about that or provide copies. There’s a beautiful symphonies that survived, they had great success on many federation worlds. Some paintings can be found on museums, and the books can be read having been copied and recorded for the enjoyment of everyone. The survival ship had with them some of those precious items, but a lot got lost, or presumed so.
There are certain steps to an individual’s life that are extremely important and they believe that rushing through those periods are sacrilege. All first steps are important throughout their life. For a woman or a man, the age of becoming one of the community is very important, because it is also the achievement of reaching wisdom and take decisions around 50 years old. Before that time, it is the “Time of Growth” the period which the older are more permissive with the “young” yet guide them.
Marriage is important, but they are not the ones to keep a couple together no matter what. They have a ritual where one listen to the other, reciting a ritualized text and vice a versa. Sexuality is view has an higher plane and one of the steps that is taboo to rush but has they evolved, now it depends on a lot of factors. They have a day to pray for the memories of people gone (a day of complete silence), they have a three day ritual to celebrate life in all forms. This period is usually where the weddings are celebrated.