A strain of extremely halophilic archaea was isolated from an Upper Devonia
n oil stratum. Based on its phenotypic and genotypic properties, the isolat
e was identified as Halorubrum distributum INMI 352. Its cultures contained
viable cells with cyst-like ultrastructure. Presumably, these halophilic a
rchaea have survived in the Upper Devonian oil field under conditions unfav
orable for growth.