The Taxonomic Hierarchy |
The taxonomic hierarchy is a method of grouping together living organisms that share common features. The basis of the system in use today was formulated by Swedish biologist Carl Linnaeus (1707-1778).
The hierarchy starts with the largest groups and goes down to specific species. Using the Indian Elephant as an example:-
| Domain | Eukarya | Organisms with a complex cell structure | |
| Kingdom | Animalia | Animals | |
| Phylum | Chordata | Organisms with a backbone | |
| Class | Mammalia | Placental animals that suckle their young | |
| Order | Proboscidea | Animals with a proboscid trunk | |
| Family | Elephantidae | Elephantine Mammals | |
| Genus | Elephas | Elephants | |
| Species | Maximus | Indian Elephant |
Given that there are of thousands of genera and millions of species, the table below shows the hierarchy down to Sub-Order level only.
| DOMAIN | KINGDOM | PHYLUM | CLASS | Sub-CLASS | ORDER | Sub-ORDER | Description |
| Bacteria | Cyanophyta | Blue-green algae | |||||
| Schizomiceta | Photo-synthesising Bacteria | ||||||
| Archaea | Methanogenia | Intestinal bacteria | |||||
| Thermoacidiphilia | Bacteria from hot springs | ||||||
| Halophilitia | Marine bacteria | ||||||
| Eukarya | Protoctista | Rhodophyta | Solenoporacaea | Red Algae | |||
| Corallinacaea | Marine colonial organisms | ||||||
| Chlorophyta | Green Algae | ||||||
| Rhizopoda | Single-celled organisms that move through pseudopoda | ||||||
| Chrysophyta | Flagellates | ||||||
| Pyrrophyta | Dinoflagellates | ||||||
| Protozoa | Foraminifera | Marine micro-organisms with a calcareous shell | |||||
| Radiolaria | Marine micro-organisms with a siliceous shell | ||||||
| Ciliata | Marine micro-organisms with a chitinous shell | ||||||
| Bacillariophyta | Diatoms | ||||||
| Myxomycota | Plasmodial slime moulds | ||||||
| Acrasiomyota | Cellular slime moulds | ||||||
| Fungi | Zygomycota | Parasitic fungi | |||||
| Ascomycota | Yeasts & Truffles | ||||||
| Basidiomycota | Mushrooms puffballs etc | ||||||
| Mycophycomycota | Lichens | ||||||
| Deuteromycota | Penicillin | ||||||
| Plantae | Bryophyta | Hepticae | Liverworts | ||||
| Anthocerotae | Hornworts | ||||||
| Musci | Mosses | ||||||
| Tracheophyta | Psilopsida | The first land plants | |||||
| Lycopsida | Club mosses | ||||||
| Sphenopsida | Horsetails | ||||||
| Phyllicopsida | Ferns | ||||||
| Gymnospermopsida | Pteridospermales | Seed Ferns (extinct) | |||||
| Cycadeoidales | Cycads | ||||||
| Ginkgoales | Ginkgoes | ||||||
| Cordaitales | Primitive Trees (extinct) | ||||||
| Voltziales | Trees similar to Araucaria (extinct) | ||||||
| Coniferales | Conifers | ||||||
| Angiospermopsida | Magnoliidae | dicots | |||||
| Liliidae | monocots | ||||||
| Animalia | Porifera | Sponges | |||||
| Archeocyathida | Extinct colonial organisms | ||||||
| Cnidaria | Scyphozoa | Jellyfish | |||||
| Hydrozoa | Anenomes | ||||||
| Anthozoa | Rugosa | Corals with 4 primary septa | |||||
| Scleractina | Corals with 6 primary septa | ||||||
| Tabulata | Tabulate corals | ||||||
| Bryozoa | Marine colonial organisms | ||||||
| Brachiopoda | Shellfish | ||||||
| Nematoda | Roundworms | ||||||
| Platyhelminthes | Turbellaria | Planarians | |||||
| Trematoda | Flukes | ||||||
| Cestoda | Tapeworms | ||||||
| Annelida | Oligochaeta | Earthworms | |||||
| Polychaeta | Lugworms | ||||||
| Hirudinea | Leeches | ||||||
| Mollusca | Monoplacophera | Primitive mollusc with bilaterla symmetry | |||||
| Polyplacophora | i.e. Barnacles | ||||||
| Scaphopoda | Scaphopods | ||||||
| Bivalvia | Shellfish | ||||||
| Gastropoda | Snails slugs | ||||||
| Cephalopoda | Tetrabranchiata | Nautiloidea | Nautiloids | ||||
| Ammonoidea | Ammonites | ||||||
| Dibranchiata | Cuttlefish squid octopus | ||||||
| Arthropoda | Arachnida | Spiders scorpions mites | |||||
| Cirripedia | Barnacles | ||||||
| Merostomata | Eurypterids | ||||||
| Insecta | Beetles flies etc | ||||||
| Crustacea | Shrimps crabs lobsters | ||||||
| Trilobata | Trilobites | ||||||
| Chilopoda | Centipedes | ||||||
| Diplopodia | Millipedes | ||||||
| Echinodermata | Starfish sea urchins brittlestars | ||||||
| Chordata | Enteropneusta | Extinct wormlike organisms | |||||
| Pterobranchia | Extinct colonial organisms | ||||||
| Graptolithina | Graptolites | ||||||
| Agnatha | Jawless Fish i.e. Lampreys Hagfish | ||||||
| Placodermi | Armoured fishes | ||||||
| Acanthodii | First fish with jaws | ||||||
| Chondrichthyes | Cartilageous Fish i.e. Sharks & Rays | ||||||
| Osteichthyes | Dipnoi | ||||||
| Actinopterygii | Bony Fish | ||||||
| Teleostei | Lungfish | ||||||
| Crossopterygii | Extinct group of fishes from the Devonian | ||||||
| Amphibia | Labyrinthodonta | Extinct group of amphibians from the late Palaeozoic/early Mesozoic | |||||
| Leptospondyli | Extinct group of amphibians from the Palaeozoic | ||||||
| Lissamphibia | Frogs Toads | ||||||
| Temnospondyli | |||||||
| Anthracosauria | Extinct reptile-like amphibians | ||||||
| Reptilia | Anapsida | Extinct group of primitive reptiles | |||||
| Archosauria | Chelonia | Turtles | |||||
| Dinosauria | Dinosaurs | ||||||
| Pterosauria | Flying Reptiles | ||||||
| Crocodilia | Crocodiles | ||||||
| Lepidosauria | Lizards | ||||||
| Squamata | Snakes | ||||||
| Euryapsida | Extinct group of reptiles from the Mesozoic | ||||||
| Ichtiopterygia | Extinct group of marine reptiles | ||||||
| Synapsida | Extinct mammal-like reptiles from the Permo-Triassic | ||||||
| Aves | Birds | ||||||
| Mammalia | Prototheria | Monotreme Mammals | |||||
| Metatheria | Marsupial Mammals | ||||||
| Eutheria | Placental Mammals |
