Belongs within: Anthozoa.
Contains: Cerianthidae, Zoanthidea, Rugosa, Tabulata, Halysitidae, Actiniaria, Antipatharia, Corallimorpharia, Scleractinia.
The Hexacorallia are a major group of cnidarians including the stony corals, sea anemones and related taxa. Most species have hexamerous symmetry though some are octomerous or decamerous. The group is more reliably characterised by the presence of spirocysts, cnidae with a single-walled capsule and a tubule composed of tiny entangling subthreads (Daly et al. 2007).
Subgroups of the Hexacorallia include the Ceriantharia, which are solitary, elongate polyps that live burrowed into sediment and contained within a flexible tube constructed from discharged cnidae and mucus (Daly et al. 2007). Relicanthus daphneae is a large, skeleton-less hexacorallian found at deep-sea hydrothermal vents that has historically been identified as a actiniarian but has been placed in an isolated position by recent molecular analyses (Rodríguez et al. 2014).
Hexacorallia [Ceriantipatharia]
|--CerianthariaRB14
| |--IsarachnanthusRB14 [ArachnanthidaeDB07, Penicillaria]
| | `--I. nocturnusRB14
| `--CerianthidaeDB07
`--+--+--+--ZoanthideaMQ21
| | |--Cothonion Jell & Jell 1976F97 [CothoniidaO96, Cothoniidae]
| | | `--C. sympomatum Jell & Jell 1976NS93
| | `--+--RugosaO96
| | `--DividocoralliaO96
| | |--CalyxocoralliaO96
| | `--Heterophylliidae [Heterocorallia]O96
| | |--Pseudopetraia devonica Soshkina 1951NS93
| | `--Hexaphyllia qinghaiensisNS93, CSZ03
| `--+--TabulataO96
| `--HeliolitidaO96
| | i. s.: EllisitesJB12
| |--HalysitidaeNS93
| |--Pycnolithus [Pycnolithidae]NS93
| | `--P. bifidus Lindstrom 1899NS93
| |--CoccoserididaeNS93
| | |--Coccoseris speleana Hill 1957F71
| | `--AcidolitesNS93
| |--TaeniolitidaeNS93
| | |--Wormsipora hirsutus (Lindstrom 1899)NS93
| | `--Bogimbailites sytovae Bondarenko 1966NS93
| |--StelliporellidaeNS93
| | |--Parastelliporella columella Lin & Chow 1977NS93
| | `--PodollitesNS93
| |--PseudoplasmoporidaeNS93
| | |--Visbylites stella (Lindstrom 1899)NS93
| | `--Pachyhelioplasma kettnerovae Kim 1966NS93
| |--SibiriolitidaeNS93
| | |--Mongoliolites paradoxides Bondarenko & Minzhin 1977NS93
| | `--SibiriolitellaNS93
| |--PlasmoporellidaeNS93
| | |--Plasmoporella convexotabulataF71
| | `--Camptolithus papillata (Rominger 1876)NS93
| |--PalaeoporitidaeNS93
| | |--Trochiscolithus micraster (Lindstrom 1899)NS93
| | `--Palaeoporites estonicus Kiaer 1899NS93
| |--Heliolites [Heliolitidae]NS93
| | |--H. daintreei (see below for synonymy)F71
| | |--H. inordinatus (Lonsdale 1839)NS93
| | `--H. porosus Goldfuss 1826NS93
| |--ProheliolitidaeNS93
| | |--Kiaerolites kalstadensis Bondarenko 1977NS93
| | |--Protoheliolites norvegicus Bondarenko 1977NS93
| | `--Avicenia aseptata Leleshus 1974NS93
| |--CyrtophyllidaeNS93
| | |--Cyrtophyllum densum Lindstrom 1882NS93
| | |--Karagemia altaica Dzubo 1960NS93
| | `--Rhaphidophyllum constellatum Lindstrom 1882NS93
| |--+--Innapora incredula (Chernova in Kovalevskiy et al. 1960)NS93
| | `--ProporaNS93
| | |--P. conferta [incl. Plasmopora shearsbyi Dun 1927]F71
| | `--P. tubulata (Lonsdale 1839)NS93
| `--PlasmoporidaeNS93
| |--SquameolitesNS93
| `--PlasmoporaNS93
| |--P. gippslandica [incl. Heliolites regularis Dun 1927]F71
| |--P. heliolitoides (see below for synonymy)F71
| `--P. petalliformis Lonsdale 1839NS93
`--+--ActiniariaMQ21
`--+--Relicanthus Rodríguez & Daly in Rodríguez, Barbeitos et al. 2014MQ21, RB14 [Relicanthidae]
| `--*R. daphneae [=Boloceroides daphneae]RB14
`--+--AntipathariaMQ21
`--+--CorallimorphariaRB14
`--ScleractiniaMQ21
Hexacorallia incertae sedis:
AulosmiliaSR02
Hughaea Lamouroux 1821RL03
`--H. caribaeorum Duchassaing 1850RL03
LophoserisH04
|--L. divaricataH04
`--L. frondiferaH04
Tridacophyllia lactucaH04
Lithophyllia laceraH04
AstraeaH04
|--A. expansaH04
`--A. magnificaH04
Pterogyra laxaH04
NumidiaphyllumNS93 [NumidiaphyllidaeG02]
`--N. gillianum Flügel 1976NS93
Kilbuchophyllia Scrutton & Clarkson [Kilbuchophyllida, Kilbuchophyllidae]O96
`--*K. discoidea Scrutton & Clarkson 1991O96
Tabuloconus kordaeO96
Flindersipora bowmaniO96
Moorowipora chamberensis Fuller & Jenkins 1994B96
Heliolites daintreei [incl. H. regularis var. humewoodensis Dun 1927, H. jackii Dun 1927, H. wellingtonensis Dun 1927 (n. n.), H. yassensis Dun 1927]F71
Plasmopora heliolitoides [incl. Heliolites distans Dun 1927, H. distans var. humewoodensis Dun 1927, H. distans var. intermedia Dun 1927, H. distans var. minuta Dun 1927]F71
*Type species of generic name indicated
References
[CSZ03] Chen, Z.-Q., G. R. Shi & L.-P. Zhan. 2003. Early Carboniferous athyridid brachiopods from the Qaidam Basin, northwest China. Journal of Paleontology 77: 844–862.
[DB07] Daly, M., M. R. Brugler, P. Cartwright, A. G. Collins, M. N. Dawson, D. G. Fautin, S. C. France, C. S. McFadden, D. M. Opresko, E. Rodriguez, S. L. Romano & J. L. Stake. 2007. The phylum Cnidaria: a review of phylogenetic patterns and diversity 300 years after Linnaeus. Zootaxa 1668: 127–182.
[F97] Fedorowski, J. 1997. Rugosa and Scleractinia—a commentary on some methods of phylogenetic reconstruction. Acta Palaeontologica Polonica 42 (3): 446–456.
[F71] Fletcher, H. O. 1971. Catalogue of type specimens of fossils in the Australian Museum, Sydney. Australian Museum Memoir 13: 1–167.
[G02] Gudo, M. 2002. Soft body reconstructions of Palaeozoic corals: implications for the system of Anthozoa (Coelenterata). Lethaia 35: 328–344.
[H04] Haeckel, E. 1899–1904. Kunstformen der Natur. Bibliographisches Institut: Leipzig und Wien.
[JB12] Johnson, M. E., & B. G. Baarli. 2012. Development of intertidal biotas through Phanerozoic time. In: Talent, J. A. (ed.) Earth and Life: Global biodiversity, extinction intervals and biogeographic perturbations through time pp. 63–128. Springer.
[MQ21] McFadden, C. S., A. M. Quattrini, M. R. Brugler, P. F. Cowman, L. F. Dueñas, M. V. Kitahara, D. A. Paz-García, J. D. Reimer & E. Rodríguez. 2021. Phylogenomics, origin, and diversification of anthozoans (phylum Cnidaria). Systematic Biology 70 (4): 635–647.
[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.
[O96] Oliver, W. A., Jr. 1996. Origins and relationships of Paleozoic coral groups and the origin of the Scleractinia. Paleontological Society Papers 1: 107–134.
[RB14] Rodríguez, E., M. S. Barbeitos, M. R. Brugler, L. M. Crowley, A. Grajales, L. Gusmão, V. Häussermann, A. Reft & M. Daly. 2014. Hidden among sea anemones: the first comprehensive phylogenetic reconstruction of the order Actiniaria (Cnidaria, Anthozoa, Hexacorallia) reveals a novel group of hexacorals. PLoS One 9 (5): e96998.
[RL03] Ryland, J. S., & J. E. Lancaster. 2003. Revision of methods for separating species of Protopalythoa (Hexacorallia: Zoanthidea) in the tropical West Pacific. Invertebrate Systematics 17: 407–428.
[SR02] Stolarski, J., & A. Russo. 2002. Microstructural diversity of the stylophyllid (Scleractinia) skeleton. Acta Palaeontologica Polonica 47 (4): 651–666.