The name Thermus ruber Loginova, Egorova, Golovacheva, and Seregina 1975 is revived for the same organism on which the original description was based. The temperature range for growth on a potato-peptone-yeast extract medium is 37 to 70°C, and the optimum temperature for growth is 60°C. T. ruber is characterized by the production of an intracellular bright red (or occasionally bright orange) carotenoid pigment with an absorption spectrum similar to that of retro-dehydro–γ-carotene (or occasionally neuro-sporaxanthine). The type strain is strain 1258 in the All-Union Collection of Microorganisms, Moscow, USSR.