Editing Apicomplexa (section)

===History===
The first Apicomplexa protozoan was seen by [[Antonie van Leeuwenhoek]], who in 1674 saw probably [[oocyst]]s of ''[[Eimeria stiedae]]'' in the [[gall bladder]] of a [[rabbit]]. The first species of the [[phylum]] to be described, ''[[Gregarina ovata]]'', in [[earwig]]s' intestines, was named by Dufour in 1828. He thought that they were a peculiar group related to the [[trematode]]s, at that time included in [[Vermes]].<ref name="Levine (1988b)" /> Since then, many more have been identified and named. During 1826–1850, 41 species and six genera of Apicomplexa were named. In 1951–1975, 1873 new species and 83 new genera were added.<ref name="Levine (1988b)">{{cite journal | author = Levine N. D. | year = 1988 | title = Progress in taxonomy of the Apicomplexan protozoa | journal = The Journal of Protozoology | volume = 35 | issue = 4| pages = 518–520 |pmid=3143826 | doi=10.1111/j.1550-7408.1988.tb04141.x}}</ref>

The older taxon Sporozoa, included in [[Protozoa]], was created by [[Rudolf Leuckart|Leuckart]] in 1879<ref>{{cite book |first=R. |last=Leuckart |title=Die menschlichen Parasiten |publisher=Winter |location=Leipzig |year=1879 |edition=2nd |volume=1 |url=https://www.europeana.eu/portal/record/9200143/BibliographicResource_2000069323145.html}}</ref> and adopted by [[Otto Bütschli|Bütschli]] in 1880.<ref>Bütschli, O. (1880-82). ''Dr. H.G. Bronn's Klassen und Ordnungen des Thier-Reichs''. Erster Band: Protozoa. Abt. I, Sarkodina und Sporozoa, [https://archive.org/details/drhgbronnsklasse0101bron].</ref> Through history, it grouped with the current Apicomplexa many unrelated groups. For example, Kudo (1954) included in the Sporozoa species of the [[Ascetosporea]] ([[Rhizaria]]), [[Microsporidia]] ([[Fungi]]), [[Myxozoa]] ([[Animalia]]),  and ''[[Helicosporidium]]'' ([[Chlorophyta]]), while Zierdt (1978) included the genus ''[[Blastocystis]]'' ([[Stramenopiles]]).<ref>{{cite journal |first=G. |last=Perez-Cordon |display-authors=etal |title=Finding of ''Blastocystis'' sp. in bivalves of the genus ''Donax'' |journal=Rev. Peru. Biol. |volume=14 |issue=2 |pages=301–2 |year=2007 |doi=10.15381/rpb.v14i2.1824 |doi-access=free }}</ref> ''[[Dermocystidium]]'' was also thought to be sporozoan. Not all of these groups had spores, but all were parasitic.<ref name="Levine (1988b)" /> However, other parasitic or symbiotic unicellular organisms were included too in protozoan groups outside Sporozoa ([[Flagellata]], [[Ciliophora]] and [[Sarcodina]]), if they had flagella (e.g., many [[Kinetoplastida]], [[Retortamonadida]], [[Diplomonadida]], [[Trichomonadida]], [[Hypermastigida]]), cilia (e.g., ''[[Balantidium]]'') or pseudopods (e.g., ''[[Entamoeba]], [[Acanthamoeba]], [[Naegleria]]''). If they had cell walls, they also could be included in plant kingdom between [[bacteria]] or [[yeast]]s.

Sporozoa is no longer regarded as biologically valid and its use is discouraged,<ref>{{cite web |url=http://www.ucmp.berkeley.edu/protista/apicomplexa.html |title=Introduction to the Apicomplexa |access-date=2009-05-31| archive-url= https://web.archive.org/web/20090420123252/http://ucmp.berkeley.edu/protista/apicomplexa.html| archive-date= 20 April 2009 | url-status= live}}</ref> although some authors still use it as a synonym for the Apicomplexa. More recently, other groups were excluded from Apicomplexa, e.g., ''[[Perkinsus]]'' and ''[[Colpodella]]'' (now in Protalveolata).

The field of classifying Apicomplexa is in flux and classification has changed throughout the years since it was formally named in 1970.<ref name="Levine1970" />

By 1987, a comprehensive survey of the phylum was completed: in all, 4516 species and 339 genera had been named. They consisted of:<ref name="Levine (1988a)">{{cite book |first=N.D. |last=Levine |title=The protozoan phylum Apicomplexa |publisher=CRC Press |year=1988 |isbn=978-0849346538 }}</ref><ref name="Levine (1988b)" />
* Class [[Conoidasida]]
** Subclass [[Gregarinasina]] ''[[pro parte|p.p.]]''
*** Order [[Eugregarinorida]], with 1624 named species and 231 named genera
** Subclass [[Coccidiasina]] ''p.p''
*** Order [[Eucoccidiorida]] ''p.p''
**** Suborder [[Adeleorina]] ''p.p''
***** Group [[Hemogregarine]]s, with 399 species and four genera
**** Suborder [[Eimeriorina]], with 1771 species and 43 genera
* Class [[Aconoidasida]]
** Order [[Haemospororida]], with 444 species and nine genera
** Order [[Piroplasmorida]], with 173 species and 20 genera
* Other minor groups omitted above, with 105 species and 32 genera

Although considerable revision of this phylum has been done (the order Haemosporidia now has 17 genera rather than 9), these numbers are probably still approximately correct.<ref>{{Cite journal |last1=Karadjian |first1=Gregory |last2=Hassanin |first2=Alexandre |last3=Saintpierre |first3=Benjamin |last4=Gembu Tungaluna |first4=Guy-Crispin |last5=Ariey |first5=Frederic |last6=Ayala |first6=Francisco J. |last7=Landau |first7=Irene |last8=Duval |first8=Linda |date=2016-08-15 |title=Highly rearranged mitochondrial genome in Nycteria parasites (Haemosporidia) from bats |journal=Proceedings of the National Academy of Sciences |language=en |volume=113 |issue=35 |pages=9834–9839 |doi=10.1073/pnas.1610643113 |pmid=27528689 |pmc=5024609 |bibcode=2016PNAS..113.9834K |issn=0027-8424|doi-access=free }}</ref>