Belongs within: Rugosa.
The Pachythecaliina are a Mesozoic assemblage of corals characterised by pachytheca, distinctive thick, epithecal walls with a modular structure (Stolarski & Russo 2001).
<==Pachythecaliina [Amphiastraeina, Hexactiniaria, Hexanthiniaria, Pachythecalidae, Zardinophyllidae]
|--+--Zardinophyllum Montanaro-Gallitelli 1975RS01
| | `--Z. zardinii Montanaro-Gallitelli 1975SR01
| `--Pachythecalis Cuif 1975RS01
| `--P. major Cuif 1975SR01
`--+--Pachydendron Cuif 1975RS01
| `--P. microthallos Cuif 1975SR01
|--Pachysolenia Cuif 1975RS01
| |--*P. cylindrica Cuif 1975RS01
| |--P. mardjinaicaNS93
| `--P. primoricaRS01
`--+--+--Carolastraea Eliášová 1976 [Carolastraeidae]SR01
| | `--C. fraji Eliášová 1976SR01
| |--Intersmilia Eliášová 1974 [Intersmiliidae]SR01
| | |--I. djartyrabatica Mel’nikova in Mel’nikova & Roniewicz 1976NS93
| | `--I. irregularis Roniewicz 1976SR01
| `--DonacosmiliidaeSR01
| |--Cylismilia Roniewicz 1988SR01
| |--Parepismilia Beauvais 1964SR01
| |--Prodonacosmilia Melnikova 1976SR01
| | `--P. dronovi Mel’nikova in Mel’nikova & Roniewicz 1976NS93
| `--Donacosmilia de Fromentel 1861SR01
| `--D. coralline de Fromentel 1861SR01
`--AmphiastraeidaeSR01
| i. s.: Budaia travisensis Wells 1933NS93
| AxosmiliaNS93
|--Quenstedtiphyllia Melnikova 1975 [Quenstedtiphylliinae]RS01
| |--*Q. fritschi (Volz 1896) [=Hexastraea fritschi, Volzeia (Hexastraea) fritschi]RS01
| `--Q. mardjanaica Melnikova 1975RS01
|--Sichuanophyllia Deng & Zhang 1984 [incl. Lubowastraea Melnikova 1986]SR01
| |--S. prima (Melnikova 1986)SR01
| `--S. sichuanensis Deng & Zhang 1984SR01
`--+--HeterocoeniidaeSR01
| |--Heterocoenia Milne-Edwards & Haime 1849SR01
| |--Latusastraeopsis Morycowa & Marcopoulo-Diacantoni 1997SR01
| |--Pachycoenia Alloiteau 1952SR01
| |--Confusaforma Löser 1987SR01
| |--Latusastraea d’Orbigny 1850SR01
| | `--L. exiguis de Fromentel 1862SR01
| `--Thecidiosmilia Koby 1888SR01
| `--T. morycowae Kołodziej 1995SR01
`--AmphiastraeinaeRS01
|--Amphiastrea Étallon 1859SR01
|--Pleurostylina de Fromentel 1856RS01
|--Aulastraea Ogilvie 1897RS01
|--Hexapetalum Eliašova 1975RS01
|--Hykeliphyllum Eliašova 1975RS01
|--Cheilosmilia Koby 1888RS01 (see below for synonymy)
|--Simplexastraea Eliašova 1976SR01
|--Pseudopisthophyllum Geyer 1955SR01, RS01
|--Selenegyra Ogilvie 1897SR01
|--Amphiaulastraea Geyer 1955RS01
| `--A. rarauensis (Morycowa 1971)SR01
|--Mitrodendron Quenstedt 1881RS01
| `--M. ogilviae Geyer 1955RS01
`--Pleurophyllia de Fromentel 1856RS01 [incl. Cuneiphyllia Eliašova 1978SR01]
`--P. minuscula Roniewicz 1976SR01
Cheilosmilia Koby 1888RS01 [incl. Lingulosmilia Koby 1888SR01, Opistophyllum Ogilvie 1897SR01, Sclerosmilia Koby 1888SR01]
*Type species of generic name indicated
References
[NS93] Nudds, J. R., & J. J. Sepkoski Jr. 1993. Coelenterata. In: Benton, M. J. (ed.) The Fossil Record 2 pp. 101–124. Chapman & Hall: London.
[RS01] Roniewicz, E., & J. Stolarski. 2001. Triassic roots of the amphiastraeid scleractinian corals. Journal of Paleontology 75 (1): 34–45.
[SR01] Stolarski, J., & A. Russo. 2001. Evolution of the post-Triassic pachythecaliine corals. Bulletin of the Biological Society of Washington 10: 242–256.