Tanugans were distinguished by their up-swept eyebrows and two to three successive V-shaped ridges on their foreheads, which echoed the brow line. Both genders preferred stiffly up-swept hairstyles. Tanugan males had very pronounced receding hairlines and enlarged foreheads. The foreheads of Tanugan females were only slightly enlarged.
The Tanugans were a technologically advanced civilization and maintained an orbiting research station, the Tanuga IV research station, and a facility on Tanuga IV.
In the Tanugan system of justice, the accused were guilty until proven innocent. Furthermore, witness accounts could be made by those who only heard about an event happening in addition to those involved.
In 2366, the Tanuga IV research station exploded during a visit by the USS Enterprise-D, which was to report on the status of Tanugan scientist Dr. Nel Apgar's project. Tanugan investigators took statements and attempted to apprehend Commander William T. Riker, accused of Apgar's murder. Because of the Tanugan rules for proceedings, Jean-Luc Picard insisted all the evidence be reviewed on the Enterprise with Krag present. It became clear Riker was not responsible, and Krag withdrew his request for extradition. (TNG: "A Matter of Perspective")