Belongs within: Hacrobia.
The Haptophyta are a group of aquatic flagellates, many of which are photosynthetic. Most members of this group have a covering of scales that may or may not be mineralised.
Characters (from Adl et al. 2012): Autotrophic, mixotrophic or heterotrophic cells; some in colonies or filaments; motile cells often possessing a filiform appendage (haptonema) situated between cilia; characteristic cell covering of unmineralised and/or mineralised scales; motile cells with two cilia generally without appendages, inserted apically or sub-apically in papilla or groove, or emerging from papilla; 1–4 chloroplasts with thylakoids in groups of three; chloroplasts with immersed or bulging pyrenoid; nucleus usually posterior; outer membrane of nuclear envelope continuous with outer chloroplast membrane; major pigments chlorophylls a, c1, and c2 with c3 in prymnesiophyceans, β-carotene, diadinoxanthin, and diatoxanthin; chrysolaminarin often the main storage product; eyespots recorded in some Pavlovophyceae; life cycles include either single phases or alternating stages; in those with alternating stages, palmelloid (colonial) or filamentous stages alternate with motile stages; sexual reproduction may be common in prymnesiophyceans; some species ichthyotoxic.
Haptophyta [Haptophytina]
| i. s.: Calcidiscus leptoporus QT03
|--Rappephyceae C-SCL15
`--+--Pavlovophyceae [Pavlovophycidae] C-SCL15
| |--Diacronema C-SC06
| | |--D. lutheri C-SCL15
| | `--D. vlkianum C-SC06
| |--Pavlova C-SC06 [Pavlovaceae, Pavlovales]
| | |--P. gyrans MO08
| | |--P. lutheri MO08
| | `--P. salina C-SA96
| `--Exanthemachrysis AS12
`--Coccolithophyceae (see below for synonymy) C-SCL15
| i. s.: Umbilicosphaera P98
| |--U. hulburtiana QT03
| `--U. sibogae P98
| Scyphosphaera P98
| |--S. apstenii P98
| `--S. recurvata P98
| Pontosphaera P98
| |--P. japonica P98
| `--P. syracusana P98
| Ahmuellerella octoradiata P98
| Arkhangelskiella cymbiformis P98
| Anoplosolenia brasiliensis P98
| Rhabdosphaera claviger P98
| Speetonia Black 1971 FT93
| Rhabdothorax Kamptner 1958 FT93
| Syracosphaera Lohmann 1902 FT93
| Ceratolithus P79 [Ceratolithaceae P98]
| `--C. tricorniculatus P79
| Braarudosphaera [Braarudosphaeraceae] P98
| `--B. bigelowii P98
| Discoaster [Discoasteraceae] P98
| |--D. asymmetricus P79
| |--D. binodosus P79
| |--D. brouweri Tan 1927 VC88
| |--D. calcaris P79
| |--D. druggi P79
| |--D. exilis P79
| |--D. gemmeus P79
| |--D. hamatus P79
| |--D. kugleri P79
| |--D. lodoensis P79
| |--D. multiradiatus P79
| |--D. pentaradiatus P79
| |--D. quinqueramus P98
| |--D. saipanensis P79
| |--D. sublodoensis P79
| |--D. surculus P79
| `--D. tani P79
| |--D. t. tani P79
| `--D. t. nodifer P79
| Dicrateria [Dicrateriaceae, Dicrateriales] C-SA96
|--+--Imantonia rotunda C-SC06
| `--Prymnesiales AS12
| |--Chrysochromulina C-SC06
| | |--C. campanulifera OC09
| | `--C. kappa C-SC06
| `--Prymnesium [Prymnesiaceae] C-SA96
| |--P. parvum MO08
| `--P. patelliferum C-SA96
`--+--Coccolithales [Coccolithophorales] AS12
| |--Coccolithus C-SC06
| | |--C. braarudii C-SCL15
| | `--C. pelagicus C-SC06
| |--Balaniger AS12
| |--Calciosolenia [Calciosoleniaceae] AS12
| |--Hymenomonas AS12
| |--Pleurochrysis carterae AS12, MO08
| |--Reticulosphaera [Flavoretea, Flavoretophycidae, Reticulosphaeraceae, Reticulosphaerales] C-SA96
| | |--R. japonensis C-SA96
| | `--R. socialis C-SA96
| `--Wigwamma AS12
`--+--Isochrysidales C-SA96
| |--Emiliania huxleyi (Lohmann) Hay & Mohler 1967 C-SA96, AS12
| |--Isochrysis [Isochrysidaceae] MO08
| | |--I. galbana Parke 1938 C03
| | `--I. zhangjiangensis OC09
| `--Gephyrocapsa AS12
`--Phaeocystis Lagerheim 1893 C-SA96, AS12 [Phaeocystaceae]
|--P. antarctica C-SA96
|--P. globosa C-SA96
`--P. pouchetii C-SA96
Coccolithophyceae [Haptomonadida, Haptophyceae, Patelliferea, Prymnesiomonadida, Prymnesiophyceae, Prymnesiophycidae] C-SCL15
*Type species of generic name indicated
REFERENCES
[AS12] Adl, S. M., A. G. B. Simpson, C. E. Lane, J. Lukeš, D. Bass, S. S. Bowser, M. W. Brown, F. Burki, M. Dunthorn, V. Hampl, A. Heiss, M. Hoppenrath, E. Lara, E. Le Gall, D. H. Lynn, H. McManus, E. A. D. Mitchell, S. E. Mozley-Stanridge, L. W. Parfrey, J. Pawlowski, S. Rueckert, L. Shadwick, C. L. Schoch, A. Smirnov & F. W. Spiegel. 2012. The revised classification of eukaryotes. Journal of Eukaryotic Microbiology 59 (5): 429–493.
[C-SA96] Cavalier-Smith, T., M. T. E. P. Allsopp, M. M. Haueber, G. Goethe, E. E. Chao, J. A. Couch & U.-G. Maier. 1996. Chromobiote phylogeny: the enigmatic alga Reticulosphaera japonensis is an aberrant haptophyte, not a heterokont. European Journal of Phycology 31: 255–263.
[C-SC06] Cavalier-Smith, T., & E. E.-Y. Chao. 2006. Phylogeny and megasystematics of phagotrophic heterokonts (kingdom Chromista). Journal of Molecular Evolution 62: 388–420.
[C-SCL15] Cavalier-Smith, T., E. E. Chao & R. Lewis. 2015. Multiple origins of Heliozoa from flagellate ancestors: new cryptist subphylum Corbihelia, superclass Corbistoma, and monophyly of Haptista, Cryptista, Hacrobia and Chromista. Molecular Phylogenetics and Evolution 93: 331–362.
[C03] Chan, B. K. K. 2003. Studies on Tetraclita squamosa and Tetraclita japonica (Cirripedia: Thoracica) II: larval morphology and development. Journal of Crustacean Biology 23 (3): 522–547.
[FT93] Fensome, R. A., F. J. R. Taylor, G. Norris, W. A. S. Sarjeant, D. I. Wharton & G. L. Williams. 1993. A classification of living and fossil dinoflagellates. Micropaleontology Special Publication 7: i–viii, 1–351.
[MO08] Moore, R. B., M. Oborník, J. Janouškovec, T. Chrudimský, M. Vancová, D. H. Green, S. W. Wright, N. W. Davies, C. J. S. Bolch, K. Heimann, J. Šlapeta, O. Hoegh-Guldberg, J. M. Logsdon, Jr. & D. A. Carter. 2008. A photosynthetic alveolate closely related to apicomplexan parasites. Nature 451: 959–963.
[OC09] Okamoto, N., C. Chantangsi, A. Horák, B. S. Leander & P. J. Keeling. 2009. Molecular phylogeny and description of the novel katablepharid Roombia truncata gen. et sp. nov., and establishment of the Hacrobia taxon nov. PLoS One 4 (9): e7080.
[P79] Papp, A. 1979. Tertiary. In: Robison, R. A., & C. Teichert (eds) Treatise on Invertebrate Paleontology pt A. Introduction. Fossilisation (Taphonomy), Biogeography and Biostratigraphy pp. A488–A504. The Geological Society of America, Inc.: Boulder (Colorado), and The University of Kansas: Lawrence (Kansas).
[P98] Prothero, D. R. 1998. Bringing Fossils to Life: An introduction to paleobiology. WCB McGraw-Hill: Boston.
[QT03] Quinn, P., H. R. Thierstein, L. Brand & A. Winter. 2003. Experimental evidence for the species character of Calcidiscus leptoporus morphotypes. Journal of Paleontology 77 (5): 825–830.
[VC88] Vermeij, G. J. & T. M. Collins. 1988. Nerita fortidentata, a new gastropod from the Neogene of Panamá, with comments on the fossil record of Nerita in tropical America. Nautilus 102 (3): 102–105.
