Yasgnorns are an extinct sentient species native to now sterile Erima, third moon of Pagoma,Mirabilis System,Sombrero galaxy.
Yasgnorns biochemistry was based on methane. They have a very bitter rivalry with Grenusheans over colonization of Mirabilis outer system. This have led to nuclear war between the two species 10 million years ago. Orbital strikes on Erima had a secondary effect of releasing large cantities of free molecular oxygen, which it was toxic to all Erima's life, in atmosphere.
Yasgnorns resembled earth scorpions with claws to manipulate objects. They first appear on Erima 20 millions year ago. Their height was an average of 5 metters and weight 200 kg. They breathed CH4 and N2 which in their body were transform in different complex molecules.
Yasgnorn were an hive minded species. Various hives have battled for dominance before Iwaijama hive have united Erima under their rule. The queens were the larger member and the only fertile females, their purpose was to reproduce. The government was in control of barons, fertile males. Soldiers were infertile males with very sharp claws and toxine producing glandes. Workers were infertile females who were in charge of agriculture and construction. Science,technology and engineering were domains of tekies, hermaphrodite yasgnorns.
Yasgnorn left many ruins on their homeworld. Human archaeologist have a great interest in them. Some artifacts were taken by Venaliri robotic drones. For this humans don't completely understand Yasgnorn society and history.