Descendants of the Finger Fishers.
Bat People: While they don't fly their sail-wing-thingies and fearsome facial features are invocative of both bats and pterosaurs.
Bizarre Alien Locomotion: The Sail People used wing-like arms to catch the wind as they drifted across the water.
The Grand Hunt: Once they finally settled down and stopped with the warfare, they still had to deal with their race's violent urges. Therefore they would regularly organize broad hunts of the local sea life.
Multipurpose Tongue: The Sail People used forked tongues instead of hands, their arms having been re-shaped into wing-like forms.
Space Orcs: Marine edition. While they are not evil outright they are noted as inherently oriented towards extreme violence and their history is marked by constant warfare.