After Parker, 1982

<==o Coccidia
   |-- Rhytidocystidae [Agamococciida]
   |--o Protococciida
   |  |-- Eleutheroschizonidae
   |  `-- Grelliidae
   `--o Eucocciida
      |-- Plasmodiidae [Haemosporina]
      |--o Adeleina
      |  |-- Adeleidae
      |  |-- Legerellidae
      |  |-- Haemogregarinidae
      |  `-- Klossiellidae
      `--o Eimeriina
         |-- Spirocystidae
         |-- Selenococciidae
         |-- Dobelliidae
         |-- Aggregatidae
         |-- Caryotrophidae
         |-- Cryptosporidiidae
         |-- Pfeifferinellidae
         |-- Lankesterellidae
         |-- Eimeriidae
         `-- Sarcocystidae

Reference(s):