Lansor's species

From Memory Alpha, the free Star Trek reference

Lansor's species were a humanoid species distinguished by a bifurcating (cartilaginous) ridge running vertically down the forehead stopping at the nose. They were native to the Delta Quadrant.

Members of this species came into contact and were assimilated by the Borg sometime before the 2370s, when a Borg sphere crashed on Planet 1865-Alpha, severing the three surviving Borg drones from the Collective. Among the drones was Lansor, who managed to escape the Collective permanently some time before 2376. (VOY: "Survival Instinct").

Some speculation has suggested that Dala, Mobar and Zar (seen in "Live Fast and Prosper") were of the same species as Lansor, but, while they shared similar prosthetic make up, there is no canon evidence to support this. Similarly, P'Chan could also have been a member of Lansor's people, as he too was distinguished by a ridge - though his lack of hair could discount that possibility. P'Chan was said to be a member of Species 571.