Kingdom - Protozoa

Name derivation: "first animals"

  • Phylum: Amoebozoa
  • Phylum: Calcitarcha
  • Phylum: Choanozoa
  • Phylum: Euglenozoa
  • Phylum: Loukozoa
  • Phylum: Metamonada
  • Phylum: Microsporidia
  • Phylum: Mycetozoa
  • Phylum: Sarcomastigophora
  • Phylum: Sulcozoa
  • Four further classes not assigned to a phylum

Number of Classes: 41

Number of Orders: 74

Number of Families: 227

Number of Genus: 1,090

Number of known Species: 32,000 (approximate extant species)

Earliest Fossil Record:  Statherian 1,800 mya

Habitat: Marine, Freshwater, Terrestrial, Brackish, Parasitic

Size Range: 1 μm to 3 mm 

Notes: Previously placed as a Subkingdom within the Animalia but now a sperate Kingdom also known as Protista, however exact numbers and relationships are still under investigation. Based partly on Catalogue of Life as of July 2024 but species number is an estimate