The 3 Domains of the Tree of Life 54


Actinobacteria (Gram-positive, found mostly in soil, they help to make humus)

Aquificae (Extremophiles living in hot springs, sulfer pools, thermal ocean vents)

Bacteroidetes/Chlorobi group (Intestinal tract commensuals/Green sulfur bacteria)

Chlamydiae/Verrucomicrobia group (Intracellular bacteria/Soil and fresh water microbes)

Chloroflexi (Green nonsulfur bacteria: aerobic, filamentous, and photosynthetic)

Chrysiogenetes (Chemolithoautotroph that eats rock containing arsenic)

Cyanobacteria (Blue-green bacteria: aquatic and photosynthetic)

Deferribacteres (Anaerobic, sulfur-reducing thermophiles)

Deinococcus-Thermus (Some eat nuclear waste, survive extreme heat/cold/vacuum of space)

Dictyoglomi (Extremely thermophilic bacteria)

Fibrobacteres/Acidobacteria group (Gram-positive, acidophilic bacteria)

Firmicutes (Gram-positive bacteria, diverse group, round or rod shaped cells)

Fusobacteria (Gram-negative anaerobes living in intestinal tracts)

Gemmatimonadetes (Gram-negative, aerobic, and polyphosphate-accumulater)

Nitrospirae (Nitrite oxidizers common in soil)

Planctomycetes (Obligate aerobic aquatic bacteria reproducing by budding)

Proteobacteria (Gram-negative, large group, e.g. E. coli, Salmonella, Vibrio, purple bacteria)

Spirochaetes (Mostly long free-swiming helically coiled cells having flagella)

Thermodesulfobacteria (Thermophilic sulfate-reducing bacteria)

Thermotogae (Anaerobic thermophiles or hyperthermophiles that metabolize carbohydrates)


Crenarchaeota (Extreme thermophilic and cryophilic archaeons)

Euryarchaeota (Extreme halophiles, thermophiles, methanogens)

Korarchaeota (Hyperthermophiles: some like it hot, 85oC or 185oF)

Nanoarchaeota (Very small archaeons: hyperthermophilic symbionts)


Acanthamoebidae (Acanthopod forming amoeboid protists)

Acantharea (Free-floating marine protists with mineral skeletons that includes strontium)

Alveolata (Protists having small vesicles or alveoli in or just under the plama membrane)

Apusomonadidae (Apusomonads: gliding biflagellated bacteria-eating protists)

Centroheliozoa (Centrohelids: round bodied protists with stiff radiating arms)

Cercozoa (Protozoans: amoebae and flagellates that feed by means of filose pseudopods)

Cryptophyta (Cryptomonads: photosynthetic planktonic protists with two flagellae)

Diplomonadida group (Heterotrophic flagellates with no mitochondria)

Entamoebidae (Intestinal ameobae, a few are disease causing)

Euglenozoa (Mostly unicellular flagellates, some having chloroplasts like Euglena)

Fungi/Metazoa group (Fungi and animals like you)

Glaucocystophyceae (Glaucocystophytes: primitive freshwater algae)

Granuloreticulosea (Amoeboid protists having granular cytoplasm and pseudopodia)

Haplosporidia (Sporozoan parasites of mostly marine invertebrates)

Haptophyceae (Prymnesiophytes: marine flagellates, most with chlorophyll)

Heterolobosea (Heterotrophic amoebae: amoebo-flagellates, flagellates, and cellular slime molds)

Jakobidae (Protist flagellates with two flagella and having primitive mitochondria)

Lobosea (Amoebae with lobose pseudopods, e.g. Amoeba proteus)

Malawimonadidae (Small bacterivorous zooflagellates found in lake mud in Malawi)

Mycetozoa (Slime molds: free-living cells can assemble into giant gelatinous slugs)

Nucleariidae (Amoeboid protists with fine pseudopodia found in soil and freshwater)

Oxymonadida (Oxymonads: mostly flagellates living in the intestines of termites)

Parabasalidea (Parabasalids: mostly flagellated protozoa living in the guts of insects)

Paramyxea (Parasitic heterotrophic protists often found in the gut of marine invertebrates)

Pelobiontida (Pelobionts: primitive protists, mostly uniflagellated and lacking mitochondria)

Plasmodiophorida (Plasmodiophorids: mostly parasitic protists of plants)

Polycystinea (Marine protists: radiolaria with a skeleton of silica)

Rhodophyta (Red algae: one or multicellular up to 1 meter with chloroplasts containing red phycobilins)

Stramenopiles (Heterokonts: diverse group of tubulocristate protists)

Viridiplantae (Green algae and green plants)