Dulainian
The Dulainians were a technologically advanced humanoid species native to the planet Dulaine. They were characterized by orange skin and pale hair. ()

History
Due to their homeworld's ionically charged thermosphere blocking the use of transporters, the Dulainians built a series of orbital lifts to allow access to and from the surface.

In 2382, one of the orbital lifts malfunctioned. The  hosted the stranded travelers while an away team consisting of Commander Jack Ransom, Lieutenant Commander Andy Billups, and Ensigns Beckett Mariner and Sam Rutherford was dispatched to effect repairs. Ransom, wanting to prove that Beckett would disobey his orders, deliberately assigned her and himself to the repairs and Billups and Rutherford to liaising with the Dulainians, despite the mismatch with their respective aptitudes. 

After Billups and Rutherford unwittingly offended the Dulainian religion by entering a sacred hall with covered belly buttons, and were taken to the sentient volcano Morgo to be sacrificed, Ransom admitted his unprofessional motivations and, with their shuttle already dispatched to the surface, skydived with Mariner from the lift to intervene. Knowing that the Dulainians prized physical health above all, Ransom revealed his muscular physique to them, impressing their leaders enough for them to listen to his parley. ()

Society and culture
The Dulainians had a "wellness-based" society that held health as their highest calling. They accordingly valued exercise, evidenced by practices such as public wrestling displays and building climbing walls into their orbital lifts, and regarded superlative physical condition as a sign of wisdom. The Dulainians were also famed for their hospitality, wherein guests were pampered, adorned with flower garlands, and treated to dances, feasts, and drinking competitions. Instead of handshakes, they greeted each other by kissing with tongue.

Dulainian religion centered on Volcanic Lord Morgo, an ancient volcano god known as the "Navel of the Planet". Thus, the belly button was highly significant to Dulainian culture, appearing on their national symbol and as the means by which their spacesuits were activated. Dulainians dressed skimpily, leaving their midriffs bared; to enter a sacred hall with a covered belly button, particularly one that was an "outie", was a severe religious transgression. Such sinners were liable to be sacrificed to Morgo by being thrown into the lava within his summit crater.

Morgo was one of three co-leaders of the Dulainians, the other two in the late 24th century being Mendrick, a telepathic baby, and 355, a sentient computer. It was believed that having three rulers provided "a system of checks and balances". ()

Individuals
Named
 Mendrick
 Timber
Unnamed
 Unnamed Dulainians

Species