Belongs within: Ankyroida.
Mitrocystitida was identified by Parsley (1997) as a paraphyletic group with the Anomalocystitida and Lagynocystis nested within it. Members of this clade mostly have moderately to only slightly asymmetrical thecae (Ubaghs 1967). The basal ‘Mitrocystitida’ have two adorals and lack exothecal posterior processes (Ubaghs 1967).
<==Mitrocystitida [Mitrocystida]
| i. s.: Spermacystis Ubaghs 1967 [=Anomocystis Jaekel 1918 non Haeckel 1896]U67
| `--*S. ensifer (Barrande 1887) [=Anomalocystites ensifer, *Anomocystis ensifer]U67
| VizcainocarpusL03
| |--V. dentigerL03
| `--V. rutaiL03
| PromitrocystitesL03
|--Paranacystis Caster 1954 [Paranacystidae]U67
| `--*P. petrii Caster 1954U67
`--Mitrocystitidae [Mitrocystidae]U67
|--Ovocarpus monceretiP97, L03
`--+--Chauvelia discoidalis Cripps 1990P97, B93
`--+--AspidocarpusP97
| |--A. bohemicus Ubaghs 1979B93
| `--A. discoidalisL03
`--+--Mitrocystites Barrande 1887P97, U67 [=Mitrocystis Bather 1889U67]
| |--*M. mitra Barrande 1887U67 [incl. M. latus Jaekel 1918U67, J18]
| | |--M. m. mitraU67
| | `--M. m. hanusiU67
| `--M. riadanensisU67
`--+--Mitrocystella Jaekel 1901P97, U67
| |--*M. incipiens (Barrande 1887) [=Anomalocystites incipiens]U67
| | |--M. i. incipiensU67
| | `--M. i. miloniU67
| `--M. barrandei Jaekel 1918PP03
`--+--Eumitrocystella savilli Beisswenger 1994P97, L03
`--+--Barrandeocarpus jaekeli Ubaghs 1979P97, L03
`--+--Diamphidiocystis drepanon Kolata & Guensburg 1979P97, L03
`--Anomalocystitida [Anomalocystida, Placocystida]U67
|--Australocystidae [Australocystinae]U67
| |--Australocystis Caster 1954U67
| | `--*A. langei Caster 1954U67
| `--Placocystella Rennie 1936U67
| `--*P. capensis Rennie 1936U67
`--Anomalocystitidae (see below for synonymy)U67
| i. s.: Basslerocystis Caster 1952U67
| `--*B. disparilis (Hall 1859) [=Anomalocystites disparilis]U67
| Victoriacystis Gill & Caster 1960U67
| `--*V. wilkinsi Gill & Caster 1960U67
|--+--Anomalocystites Hall 1859P97, U67 (see below for synonymy)
| | |--*A. cornutus Hall 1859 [=*Anomalocystis cornuta, *Anomocystis cornuta]U67
| | `--A. bohemicusU67
| `--Enoploura Wetherby 1879P97, U67 [=Enopleura Springer 1913K67]
| |--*E. balanoides (Meek 1872) [=Anomalocystites (Ateleocystites) balanoides]U67
| |--E. popeiU67
| |--E. punctataU67
| `--E. wetherbyiU67
`--+--+--Allanicytidium Caster & Gill in Ubaghs 1967P97, U67 [Allanicytidiidae]
| | `--*A. flemingi Caster & Gill in Ubaghs 1967U67
| `--+--NotocarposP97
| `--TasmancytidiumP97
`--+--Ateleocystites Billings 1838P67, U67 (see below for synonymy)
| |--*A. huxleyi Billings 1838 (see below for synonymy)U67
| `--A. guttenbergensis Kolata & Jollie 1982L03
`--+--Rhenocystis Dehm 1932P97, U67
| `--*R. latipedunculata Dehm 1932U67
`--Placocystites de Koninck 1869P97, U67 [=Placocystis Haeckel 1896U67]
|--*P. forbesianus de Koninck 1869 [=*Placocystis forbesianus]U67
|--P. africanusU67
`--‘Placocystis’ crustaceaH04
Anomalocystites Hall 1859P97, U67 [=Anomalocystis Bather 1889U67, Anomocystis Haeckel 1896U67]
Anomalocystitidae [Anomalocystidae, Anomocystida, Atelocystida, Basslerocystinae, Enoplourinae, Placocystidae, Placocystinae, Placocystitidae]U67
Ateleocystites Billings 1838P97, U67 [=Atelecystis Bather 1889U67, Ateleocystis Lindström 1888U67, Atelocystis Haeckel 1896U67]
*Ateleocystites huxleyi Billings 1838 [=*Atelecystis huxleyi, *Ateleocystis husleyi, *Atelocystis huxleyi]U67
*Type species of generic name indicated
References
[B93] Benton, M. J. 1993. Basal deuterostomes (chaetognaths, hemichordates, calcichordates, cephalochordates and tunicates). In: Benton, M. J. (ed.) The Fossil Record 2 pp. 529–535. Chapman & Hall: London.
[H04] Haeckel, E. 1899–1904. Kunstformen der Natur. Bibliographisches Institut: Leipzig und Wien.
[J18] Jaekel, O. 1918. Phylogenie und System der Pelmatozoen. Paläontologische Zeitschrift 3: 1–128.
[K67] Kesling, R. V. 1967. Cystoids. In: Moore, R. C. (ed.) Treatise on Invertebrate Paleontology pt S. Echinodermata 1. General characters. Homalozoa—Crinozoa (except Crinoidea) vol. 1 pp. S85–S267. The Geological Society of America, Inc., and The University of Kansas: Lawrence (Kansas).
[L03] Lefebvre, B. 2003. Funtional morphology of stylophoran echinoderms. Palaeontology 46 (3): 511–555.
[P97] Parsley, R. L. 1997. The echinoderm classes Stylophora and Homoiostelea: non Calcichordata. Paleontological Society Papers 3: 225–248.
[PP03] Prokop, R. J., & V. Petr. 2003. Plasiacystis mobilis gen. et sp. n., a strange “carpoid” (Echinodermata, ?Homoiostelea: Soluta) in the Bohemian Ordovician (Czech Republic). Acta Musei Nationalis Pragae, Series B, Historia Naturalis 59 (3–4): 151–162.
[U67] Ubaghs, G. 1967. Stylophora. In: Moore, R. C. (ed.) Treatise on Invertebrate Paleontology pt S. Echinodermata 1. General characters. Homalozoa—Crinozoa (except Crinoidea) vol. 2 pp. S495–S565. The Geological Society of America, Inc., and The University of Kansas: Lawrence (Kansas).