Gadmeer

The Gadmeer are a races of aliens from the Stargate Universe they are reptilian/amphibian in appearance but unlike most life in the milky way galaxy are sulphur based organisms, they are a technologically advanced race, the Gadmeer were wiped out by a larger military power and are currently extinct.

Technology
The gadmeer had some fairly advanced technology, they had music, sub-light propulsion, some weapons but limited, spaceships, advanced holographic technology, transporters/shuttles, fairly advanced biological technology (successfully grew an adult human), sensors, perhaps there most impressive technology was the terraforming technology, able to turn a completely carbon based ecosystem into a sulphur based one in just a matter of weeks, this is achieved via an energy curtain that is deployed from a ship.

Biology
The Gadmeer were a sulphur based peaceful people, they look reptilian/amphibian in appearance and have two arms and two legs with a tail, there ears are very different from a humans as when humans here they're music it is unpleasant this is known to be due to human ears as the human created by the gadmeer spaceship for communication states " the music sounds most unpleasant, this is down to are ears being of the wrong design".